1989 Mariner 175Ski

[Glastron1987]

Picking up a 1989 Mariner 175Ski. Engine looks pretty clean. Appears to be a 2.4L XRI system engine.

Owner says he's been running for years with a small knock.

First of all, any comments about this model engine? Anyone have one?

Second, any ideas on what a small knock might be?

I'm think it could be anything simple like a clogged injector, to a full rebuild required.

[rock]

A knock on 2 stroke is not usually a good sign and rarely do they run "for years". I would look for something like flywheel contacting something or something else loose. If it is internal be careful.

Rock

[idvette]

I blew one up last year, was a good performer up to that point. I had a 2.4 200 xri before it, and key differences were 2:1 lower unit and a different shaped throttle cam. I was told those 2 were to get a skier out of the ditch quickly and give the driver decent low speed management. Have the knock diagnosed and if easily fixed, it'll be a solid performer.

[Glastron1987]

I blew one up last year, was a good performer up to that point. I had a 2.4 200 xri before it, and key differences were 2:1 lower unit and a different shaped throttle cam. I was told those 2 were to get a skier out of the ditch quickly and give the driver decent low speed management. Have the knock diagnosed and if easily fixed, it'll be a solid performer.
Good info, thanks.

[Aaronhl]

Did you take those spark plugs out yet

[David]

from a 1989 Mariner brochure:

175 ski 2:1 gears, 5000-5600 max rpm, 398 lb
175 carb, 1.87 gears, 5300-5800 max rpm, 382 lb
200 carb, 1.87 gears, 5400-5900 max rpm, 382 lb

[Glastron1987]

from a 1989 Mariner brochure:

175 ski 2:1 gears, 5000-5600 max rpm, 398 lb
175 carb, 1.87 gears, 5300-5800 max rpm, 382 lb
200 carb, 1.87 gears, 5400-5900 max rpm, 382 lb

Interesting

[Glastron1987]

Did you take those spark plugs out yet

Not yet. Have to get it home first.

[Glastron1987]

Spark plugs look good. Except plug #1 looked just very slightly dirtier. No aluminum on any of them.

Did compression test and 5 out of 6 were fine. #1 was very low.

Took head off and appears head gasket at the top was bad... leaking compression into the water jacket. Otherwise, all parts look fine.

I may have gotten lucky with this engine.

Will replace the head gasket and see how it runs.

Question... What do I put on the new head gasket so that it will come off OK in the future, or do I put it on dry?

[rock]

dry. oil threads on head bolts

Rock

[Glastron1987]

dry. oil threads on head bolts

Rock
Thanks.

Plan to use 2-stroke oil on the bolts and torque to 35lbs in an alternating pattern starting from the center going out and do it a little at a time.

[Glastron1987]

Little disappointed after replacing the head gasket. Compression did improve from about 45psi to about 80psi, but probably I'll try replacing that piston and rings to get it closer to 120.

In any case, it seems to start up and run fine, except there is this little hose at the top of the block that I don't know what to do with. After the engine is warmed up it dripples water out of it. On some engines, it might be attached to the poppet, but I see no connection for that on this poppet. Attached are photos. Any ideas?
523700523701

[OnPad]

Sometimes a overnight soak with seafoam, will free stuck rings.
The hose at the top of engine is for a water pressure gauge. You can block it off, or better yet install a gauge.

[Glastron1987]

Fantastic. I'll try the soaking and for now will block it off. Thank you.

[tlwjkw]

looks like you have one of tha very first of tha water cooled reg/rect. motors... first '89's didn't have tha hose from top down to tha poppet.. that came later in tha year model ('89) ta help keep tha reg/rec cool.. yours is for an added water pressure gauge....

[Mrzip]

I Have Some 200 XRI Parts. If Anyone Is Looking.. Thanks

[Glastron1987]

Still working on getting a good Seafoam soaking of that #1 cylinder. This time I will do it trimmed up.

In any case, what is even more troubling is that when I was running it on the muffs, it seemed like water was not getting up to the heads properly, and it was getting really hot. No water was coming out of the tell-tail even after getting really hot. So, I figured the LU impeller needed replacement and replaced it.

After that, no change, it is still running hot. The only thing coming out of the tell-tail is some hot air.

To add to this, I think the owner before me may have had some similar issues because there were no thermostats in the top of the heads when I got it (I put some in immediately). Why would somebody take thermostats out of an engine? Also, an idea why water would not be getting up to the heads? Could it be a bad poppet or water tube?

[pcrussell50]

This is how I made sure I had no blockages, before I put in the thermostats and fired up a new (to me), power head:

https://youtube.com/shorts/3hwgS8gboi8?si=bKbMgejzJhqNhDrP

===

For carbon/stuck rings, people here have talked about using Mercury Power Tune. I’ve never tried it. Thankfully not needed to. But I unstuck some car engine rings by several overnight soaks in ATF, then drive and burn it off and repeat. Heard about it on the internet. BUT why wouldn’t a good quality deterrent motor oil work even better? Don’t know never tried. Maybe go with Power Tune if the legends here say so.

-Peter

[Glastron1987]

This is how I made sure I had no blockages, before I put in the thermostats and fired up a new (to me), power head:

https://youtube.com/shorts/3hwgS8gboi8?si=bKbMgejzJhqNhDrP

===

For carbon/stuck rings, people here have talked about using Mercury Power Tune. I’ve never tried it. Thankfully not needed to. But I unstuck some car engine rings by several overnight soaks in ATF, then drive and burn it off and repeat. Heard about it on the internet. BUT why wouldn’t a good quality deterrent motor oil work even better? Don’t know never tried. Maybe go with Power Tune if the legends here say so.

-Peter

Thanks for the good tips.

[OnPad]

Usually a bad poppet makes too much pressure due to being stuck closed, or torn diaphragm, but having it stuck open, or missing, could cause low pressure at idle. Maybe your adapter plate/powerhead gaskets are bad/wrong, or some sort of leak in the water pump/tube.
Someone likely was fighting with a overheat issue, instead of fixing, tossed the thermostats. If the block isn't filling up it wouldn't take long to smoke the cylinders without water, causing low compression.

Seafoam works well. It is a blend of diesel, naphtha, and alcohol. If after two overnight soaks the compression doesn't come up, it likely is damaged. If so, you should be able to see some scuffing on the exhaust side of the cylinder. Possibly with a flashlight thru the spark plug hole, definitely with the head off.

[Glastron1987]

Usually a bad poppet makes too much pressure due to being stuck closed, or torn diaphragm, but having it stuck open, or missing, could cause low pressure at idle. Maybe your adapter plate/powerhead gaskets are bad/wrong, or some sort of leak in the water pump/tube.
Someone likely was fighting with a overheat issue, instead of fixing, tossed the thermostats. If the block isn't filling up it wouldn't take long to smoke the cylinders without water, causing low compression.

Seafoam works well. It is a blend of diesel, naphtha, and alcohol. If after two overnight soaks the compression doesn't come up, it likely is damaged. If so, you should be able to see some scuffing on the exhaust side of the cylinder. Possibly with a flashlight thru the spark plug hole, definitely with the head off.

That does make sense... they probably did toss the thermostats instead of fixing the overheat problem. It does get hot fast even at idle. I have to figure out how to test the system and narrow down the failure point. I already put on the lower unit with the new impeller so I'm hoping there is a way to do that without removing it again. It was challenging putting it on while on the stand.

I'm soaking the low cylinder in Seafoam, but truthfully what is the best position to do this in (e.g. trimmed up or down), and where should the piston be placed, high or low so that not all the Seafoam leaks out?

[OnPad]

Set the piston up most of the way. Trim engine all up, trailer tongue on the ground, on a hill if you have one:)I've used a syringe and hose to shoot it around the hole.

You said you had the head off, what did it look like in there?
A water pressure gauge might help in diagnosing your cooling problem, but a mute point if you can't get some compression back in that one hole.

[Glastron1987]

Well the compression in that hole was about 45psi before I replaced the head gasket and about 90psi after. So replacing the head gasket did help somewhat. There was a visible breach in the head gasket allowing exchange between coolant and compression. There was some, what I would consider minor, scuffing in the input side of the cylinder. Right now I am not sure if that scuffing is severe enough to cause the compression leak or if the rings are compromised. Figured I would give it a good soaking with Seafoam and maybe even try to run it before pulling the piston out.

... but before running it anymore I need to correct the overhead problem first.

[Glastron1987]

With the piston most of the way up, even on the stand, I think I got it in a pretty good position for the soaking. I did use a syringe too, but just pouring it I could fill it until it overflowed.

524253

[Glastron1987]

Any way to test why no water is getting up to the heads without pulling the LU off again?

[Aaronhl]

Any way to test why no water is getting up to the heads without pulling the LU off again?

Rev it up and see how much sprays out of the fitting on top

https://www.screamandfly.com/attachment.php?attachmentid=523700&d=1693144790

[OnPad]

Pull the poppet cover, and make sure you got one in there.

[Glastron1987]

The attached photo shows the poppet pulled. Without running it, I just turned it over with the starter a while and eventually a dribble came out of the left hole. Does this seem normal, and does it indicate the impeller and water tube are functioning OK?

524479

The left hole is the smaller one. Not sure why the photo got rotated.

[OnPad]

Ummmm.... Anyone ever seen a hole in the block on the little side of the poppet cavity? I've never seen the little side with a hole in the block like that. You should have water gushing out of that hole even at cranking speed, but in my mind that hole shouldn't be there, your block wouldn't fill or hold pressure correctly. Maybe someone else has some idea?

83, 2.4L52448288, or 90? 2.4L524483

[skialot2]

The attached photo shows the poppet pulled. Without running it, I just turned it over with the starter a while and eventually a dribble came out of the left hole. Does this seem normal, and does it indicate the impeller and water tube are functioning OK?

524479

The left hole is the smaller one. Not sure why the photo got rotated.

Nope! Not normal. I have never seen a hole on the little side. It's always plugged off. That's probably your overheating problem. Find a freeze plug that will fit and plug it.

Your motor was probably run with the blown head gasket for a while. With 40psi compression, it probably wasn't running on that cylinder at all. Probably washed out the rings a little. Maybe glazed the cylinder walls. Go for a ride if it's not overheating. With 90psi it should run on that cylinder and compression may come back after a while. If it doesn't, before rebuilding, you can try pulling the head again. Push that piston down. If the cylinder walls are smooth, put some rags in the ports and take a scotchbrite pad and lightly scrub the cylinder walls down to break the glaze. Clean it out good, Put the head back on, go for a ride. Then check compression again. You might get lucky. Be careful if you have nikasil cylinders. They are thin and easy to sand through.

[pcrussell50]

Ummmm.... Anyone ever seen a hole in the block on the little side of the poppet cavity? I've never seen the little side with a hole in the block like that. You should have water gushing out of that hole even at cranking speed, but in my mind that hole shouldn't be there, your block wouldn't fill or hold pressure correctly. Maybe someone else has some idea?

I can confirm that my late 1990 2.4/200 does not have that hole in the small cavity.

Further, I have two 2.0/150’s (1986 and 1987) and they both have the two bolt poppet with the small cavity completely uncovered. Obviously no hole in the small cavity in that case.

-Peter

[rock]

I have seen them both ways. Not real sure why but it is a factory thing.

Rock

[OnPad]

I have seen them both ways. Not real sure why but it is a factory thing.

Rock

Interesting,..... That hole would lead directly to the main water feed, before it made it to the top of block, on the 1990 engine I'm looking at.
524503
At this point I think Glastron1987 would be wise to drop the lower again and check his work, or for any missing parts. It gets easier the more times you do it. If you can't find a helper, use a piece of wood to jam the case up (third hand) while you fiddle with water tube, driveshaft, and shifter. Leaving it in gear will allow you to spin the propshaft, helping align your driveshaft splines. When you have the l/u off you can remove the pipe plug you were asking about earlier, install a garden hose in that hole. While trimmed up, you may be able to back flush sand /gravel out the intake side of adapter plate.

A idling engine should fill to the top of both heads, (or the plug in the top of block) in about 20 seconds at the lake, probably faster on the hose with proper fitting muffs. Likely never with poorly fitting muffs. Once the engine is full it takes a few minutes for the thermostats to open.

[Glastron1987]

Nope! Not normal. I have never seen a hole on the little side. It's always plugged off. That's probably your overheating problem. Find a freeze plug that will fit and plug it.

Your motor was probably run with the blown head gasket for a while. With 40psi compression, it probably wasn't running on that cylinder at all. Probably washed out the rings a little. Maybe glazed the cylinder walls. Go for a ride if it's not overheating. With 90psi it should run on that cylinder and compression may come back after a while. If it doesn't, before rebuilding, you can try pulling the head again. Push that piston down. If the cylinder walls are smooth, put some rags in the ports and take a scotchbrite pad and lightly scrub the cylinder walls down to break the glaze. Clean it out good, Put the head back on, go for a ride. Then check compression again. You might get lucky. Be careful if you have nikasil cylinders. They are thin and easy to sand through.

I like the idea of once getting past the overheat problem taking it for a ride and seeing if compression comes back and if not take the scotchbrite to it. I'm still confused about the small hole though because Rock says he's seen them opened and blocked. Per Onpad I probably do need to take the LU off again and test that way.

[Glastron1987]

Rev it up and see how much sprays out of the fitting on top

https://www.screamandfly.com/attachment.php?attachmentid=523700&d=1693144790

Just a little spitting came out even when reving it.

[OnPad]

I believe Rock,... and also like the idea of blocking the little hole off, like skialot recommended. It's a leak directly down the poppet dump. Not unlike the hose from poppet cover to top of engine on later model stuff, but in a less ideal location. Maybe not enough to keep the block from filling with a operational pump, but it isn't helping. That little hole isn't far from your pump. If your having problems getting water there, you got no chance at the top of the block. We're only talking like 6 or 19 oz.of water above pump to that hole. How does a garden hose not fill the block with tight fitting muffs, properly installed (rotating) water pump and feed tube??? My guess is something isn't right in the water pump/feed, or plugged adapter plate.
The test pcrussell showed a video of is legit. Good for testing if your getting water through the block, or dislodging crud in adapter. If you were to momentarily apply water this way, then let drain, it could back flush junk out of the adapter that collects at the first low spot. Kinda the reverse of the method I mentioned a few posts back.

524553this is where all the pebbles and fishing sinkers get stuck between the two plates.

Was your poppet, and associated parts present?
How are you feeding the engine water, ...muffs, trough, or lake? Your muffs good n tight?

[tlwjkw]

:thumbsup:...
I have seen them both ways. Not real sure why but it is a factory thing.

Rock

i have, as you, seen tha hole in a few motors.. jus never paid much attention to it...... sometimes ya jus gotta wonder what merc engineers were thinkin'...........

jus gonna add..
if its got tha hole then you would think tha plate/plates may be a little different maybe???

[Glastron1987]

I believe Rock,... and also like the idea of blocking the little hole off, like skialot recommended. It's a leak directly down the poppet dump. Not unlike the hose from poppet cover to top of engine on later model stuff, but in a less ideal location. Maybe not enough to keep the block from filling with a operational pump, but it isn't helping. That little hole isn't far from your pump. If your having problems getting water there, you got no chance at the top of the block. We're only talking like 6 or 19 oz.of water above pump to that hole. How does a garden hose not fill the block with tight fitting muffs, properly installed (rotating) water pump and feed tube??? My guess is something isn't right in the water pump/feed, or plugged adapter plate.
The test pcrussell showed a video of is legit. Good for testing if your getting water through the block, or dislodging crud in adapter. If you were to momentarily apply water this way, then let drain, it could back flush junk out of the adapter that collects at the first low spot. Kinda the reverse of the method I mentioned a few posts back.

524553this is where all the pebbles and fishing sinkers get stuck between the two plates.

Was your poppet, and associated parts present?
How are you feeding the engine water, ...muffs, trough, or lake? Your muffs good n tight?

My muffs seem to fit snuggly, but the water pressure from my hose isn't really too strong. Never observed this as an issue on other motors using my hose, but I'm wondering if that is an issue.

[rock]

Might need to dip it in the crick. I have had motors show nothing on the muff but be fine in the water. Pump and lower being submerged makes aa difference on some of them.

Rock

[Glastron1987]

Might need to dip it in the crick. I have had motors show nothing on the muff but be fine in the water. Pump and lower being submerged makes aa difference on some of them.

Rock

Interesting. Now I may mount it to the boat and try it out.

[Aaronhl]

Interesting. Now I may mount it to the boat and try it out.

Order the jack plate yet ??

[Glastron1987]

Order the jack plate yet ??

Since you're pushing me, I just ordered a 6":)

[Glastron1987]

So I got the kit to replace the poppet. Should I block that small hole with a freeze plug before installing? or leave it as is? Not sure how that works.

[rock]

I would leave it alone. Merc put it here for a reason even though we can't figure out what the reason was. Pretty sure the engineers were smarter than I.

Rock

[Glastron1987]

Poppet in now. I'll start it up and see if there is any water getting to the heads.

[Glastron1987]

1) Is that a normal amount of water coming out of the thermostat holes at idle on the muffs?
2) Thought I installed the poppet right, but now I have water streaming out of the pinhole/vent at the bottom of the poppet cover. Any ideas what is wrong there?


https://youtube.com/shorts/HyWYCAX8a0s

[tlwjkw]

something amiss in tha poppet.. no tellin' what piece/gasket.. check plastic disc for being warped while your in there...

[OnPad]

Sounds rough!

[pcrussell50]

1) Is that a normal amount of water coming out of the thermostat holes at idle on the muffs?
2) Thought I installed the poppet right, but now I have water streaming out of the pinhole/vent at the bottom of the poppet cover. Any ideas what is wrong there?

One of the legends can correct me, but I don’t think there should be that much steam coming from the water. I fought that problem on my stock 2.4/200 (low flow and too much steam) a couple of months ago. For me, it was a missing black elastomer water tube grommet in the black water pump housing. Replacing that restored the flow.

I also had water weeping out the air vent hole in my poppet. A not-warped plastic disc did not fix it for me. I had to replace the rubber diaphragm. It was slightly worn around its hard-reinforced rim. Barely noticeable. You would not have thought it would be the problem unless you looked closely at it. Anyway, replacing the rubber diaphragm fixed it for me.

I want to add that my 2.4/200 has the two-chamber poppet with the barb that runs up to the starboard thermostat. It now flows enough since I installed the grommet in then pump housing. BUT I also have a 2.0/150 with the one chamber poppet that does not have that extra hose run. And it just simply flows more/pees stronger. I suspect it’s just because it has fewer fittings and hose runs to push through. The 2.4/200 still runs nice and cool even with more hose and fittings and a slightly weaker telltale.

-Peter

[Glastron1987]

Sounds rough!

Yeah we'll have to get to that too. It seemed to smooth out as I ran it, but that may be my imagination.

[Glastron1987]

something amiss in tha poppet.. no tellin' what piece/gasket.. check plastic disc for being warped while your in there...

Guess I'll have to pull it apart and see what is going on. It is difficult because I am not sure how it is supposed to work. It is clear to me that as pressure is exerted from the center it would move and open up the drain to the exhaust, but I have no idea what the outside part needs to do.

[Glastron1987]

One of the legends can correct me, but I don’t think there should be that much steam coming from the water. I fought that problem on my stock 2.4/200 (low flow and too much steam) a couple of months ago. For me, it was a missing black elastomer water tube grommet in the black water pump housing. Replacing that restored the flow.

I also had water weeping out the air vent hole in my poppet. A not-warped plastic disc did not fix it for me. I had to replace the rubber diaphragm. It was slightly worn around its hard-reinforced rim. Barely noticeable. You would not have thought it would be the problem unless you looked closely at it. Anyway, replacing the rubber diaphragm fixed it for me.

I want to add that my 2.4/200 has the two-chamber poppet with the barb that runs up to the starboard thermostat. It now flows enough since I installed the grommet in then pump housing. BUT I also have a 2.0/150 with the one chamber poppet that does not have that extra hose run. And it just simply flows more/pees stronger. I suspect it’s just because it has fewer fittings and hose runs to push through. The 2.4/200 still runs nice and cool even with more hose and fittings and a slightly weaker telltale.

-Peter

Yeah, less steam and more water sounds good to me. What is that black elastomer water tube grommet in the black water pump housing that you are referring to?

[skialot2]

If water is coming out the little vent hole on the poppit cover, the diaphragm is leaking. It could have a hole, a crack, be pinched or just installed wrong or the center screw could be loose. that hole is just so when the poppit moves out, it doesn't build pressure behind the diaphragm.

The black elastomer water tube grommet is this 524959 It goes in the water pump housing, under the water tube guide and seals the end of the water tube.524960

[Glastron1987]

If water is coming out the little vent hole on the poppit cover, the diaphragm is leaking. It could have a hole, a crack, be pinched or just installed wrong or the center screw could be loose. that hole is just so when the poppit moves out, it doesn't build pressure behind the diaphragm.

The black elastomer water tube grommet is this 524959 It goes in the water pump housing, under the water tube guide and seals the end of the water tube.524960



OK great, I get it now, about that black elastomer water tube grommet. Thank you. I will have to pull the LU to check on that.

Also, thanks for the explanation on the poppet, that makes sense to me now.

[Glastron1987]

I pulled the poppet out and examined how it was put together and it looks OK to me, but when I pour water in the small side, it just leaks out the vent hole. The diaphragm is brand new with no tears. Something's not right, but it is not obvious to me.525016

[OnPad]

Merc made two different diaphragms. That style should be the later version, part 14479. If you had the older diaphragm in there it would leak. It would also leak if the Philips head screw isn't tight.

[Glastron1987]

Merc made two different diaphragms. That style should be the later version, part 14479. If you had the older diaphragm in there it would leak. It would also leak if the Philips head screw isn't tight.

The screw is tight, and the diaphragm does appear to be the newer 14479 as opposed to the older 64877, based on the pictures I've seen and matches the one I replaced.

Not so obviously, something is not right.

[Glastron1987]

Looks like the stream coming out of that vent hole is because the outside edge of the diaphragm is supposed to mate up against the inside of the outside cover. The new gasket installed appears thicker than the original one and was not letting this mating occur. So, I replaced that with a decent used one of original thickness. The stream changed to a dripple. I think a brand-new gasket of proper thickness is order.

[Glastron1987]

So, after running it again a few times, it still heats up so I have to figure that out still.

...but I pulled the head again to look for the source of the noise that is persisting. Seem I have found it.

525149
https://youtube.com/shorts/qDhg1qETMfc

[skialot2]

That is not good. That also probably why its running hot.

[Glastron1987]

That is not good. That also probably why its running hot.

Was wondering if that could make it run hot.

[Glastron1987]

Want to try to replace the piston on the bad cylinder and see if that corrects the compression problem good enough. Any advice on the easiest way to get at the connecting rod bolts? ...or do I need to take of all of the following individually -Lazer/XRi computer, oil injection tank, fuel/water separator, high pression fuel management assembly. Any easy way to take the whole thing off in one shot?

[skialot2]

Just changing the piston is not going to fix it. That is going to need to be bored out for an oversize piston or a sleeve.

[tlwjkw]

jus re-read tha whole thing.. tha only thing i see is you replaced tha impeller.. if you didn't replace everything with tha pump ya need ta start over.. get a water pump "kit".. it should include tha pump base, stainless ride plate, stainless lined housing and all gaskets... tha two stainless pieces can be worn and ya can't tell they are outta spec... have seen this condition many times when folks "think" justa an impeller will fix it.. you should have a steady stream from tha little hose on top.. this is where ya need a pressure gauge.. you can also pull that plug tha little fitting is in and start tha motor.. you should have steady heavy stream overflow from tha hole..... same with discharge from heads with stats removed...... same amount as in pcrussell 50's video in all three places if pump is correct and healthy.......... ya may get a tad less at tha stat openings with tha plug on top removed.. might vary by opening and closing tha hole on top.... jus one other thing... GET A WATER PRESSURE GAUGE!

for tha low comp hole.. thats a chrome bore motor.. when you pulled tha head was there any aluminum stuck to tha cyl. wall? or was jus tha piston scared up?.. if tha cyl. is clean with no deposits and/or scaring replace piston and rings and move on.. if it has scaring and/or deposits it gonna need ta be sleeved.. be very aware of getting any type of debris (shavings/trash) in tha motor,, it needs ta be "clean"... piston "rock" may or may not be excessive.. you can't tell by jus "feel".. it needs ta be measured..

jmo...........

[Glastron1987]

Just changing the piston is not going to fix it. That is going to need to be bored out for an oversize piston or a sleeve.

No real disagreement there, just that I thought it might be worth try before I pull the whole thing apart.

[Glastron1987]

jus re-read tha whole thing.. tha only thing i see is you replaced tha impeller.. if you didn't replace everything with tha pump ya need ta start over.. get a water pump "kit".. it should include tha pump base, stainless ride plate, stainless lined housing and all gaskets... tha two stainless pieces can be worn and ya can't tell they are outta spec... have seen this condition many times when folks "think" justa an impeller will fix it.. you should have a steady stream from tha little hose on top.. this is where ya need a pressure gauge.. you can also pull that plug tha little fitting is in and start tha motor.. you should have steady heavy stream overflow from tha hole..... same with discharge from heads with stats removed...... same amount as in pcrussell 50's video in all three places if pump is correct and healthy.......... ya may get a tad less at tha stat openings with tha plug on top removed.. might vary by opening and closing tha hole on top.... jus one other thing... GET A WATER PRESSURE GAUGE!

for tha low comp hole.. thats a chrome bore motor.. when you pulled tha head was there any aluminum stuck to tha cyl. wall? or was jus tha piston scared up?.. if tha cyl. is clean with no deposits and/or scaring replace piston and rings and move on.. if it has scaring and/or deposits it gonna need ta be sleeved.. be very aware of getting any type of debris (shavings/trash) in tha motor,, it needs ta be "clean"... piston "rock" may or may not be excessive.. you can't tell by jus "feel".. it needs ta be measured..

jmo...........

For the overheat issue, when I said that the impeller was replaced, I did mean that the whole kit was replaced. So, at this point I will be dropping the LU and test it like pcrussell 50. Thanks.

For the cylinder issue, when I pulled the head there was no aluminum stuck anywhere that I could tell, and the spark plug even looked like it had been firing healthy and OK. The top of the piston looked fine. The cylinder wall does seem smooth though, and I can tell even without a gauge that it is too big starting at the top of the exhaust relief notch, Here is a photo:526718

[tlwjkw]

does tha block have a serial number on it anywhere (flange or welsh plug)??? reason for askin' is every 2.4 175 i've seen was a chrome bore motor.. forget anything i suggested with tha piston and ring thing being a steel sleeve motor... i've have never put eyes on whats called a "ski 175" so can't say for sure if its supposed ta be a steel sleeve or not... on tha parts list it doesn't show any size oversize pistons same as a chrome bore parts list does??? they usually show at least one oversize ).015) for a steel sleeve motor...
jmo

on tha water flow.. if you do not get good flow to tha top of tha block (where tha nipple for tha gauge is) ya got a problem between tha intakes and tha bottom of tha block (intakes, pump, water tube)

[tlwjkw]

think i got to tha bottom of it all.. looks like tha "ski" 175 uses tha XR4 rotating assy. and jus threw on a laser efi and jacked up tha rating ta 175............. so yeah, it will have steel sleeves.

[Glastron1987]

Not sure does this identify the block? 526735

[Glastron1987]

Some sort of "S" block I guess.526738

[Aaronhl]

U got that 175 ski cheap enough it might be worth putting another sleeve in it over the winter especially to keep it all as a complete unit i have never seen a block painted gray before it matches everything else

[Glastron1987]

U got that 175 ski cheap enough it might be worth putting another sleeve in it over the winter especially to keep it all as a complete unit i have never seen a block painted gray before it matches everything else

So, you know where the nearest shop is (near CT) that can do that, so I don't have to ship?

[Glastron1987]

To test the overheat issue I took down the LU and put a hose the water tube like pcrussel50 did.

Water came out of the port side, but nothing from the starboard side. So where would the blockage be?

526828526829

[Glastron1987]

I'm thinking that the flow of the water should be, maybe not exactly, but something like this:

1) Up the water tube
2) Through the exhaust and engine plates
3) Through the engine block
4) Into the heads
5) Through the thermostats
6) Out

Which means that if water is coming out of only the port thermostat hole, but not the starboard one, then the blockage is in the starboard side of the engine block.

[XstreamVking]

Or the poppet is leaking and the block can't get enough "head" pressure to fill completely.

[tlwjkw]

here it is...... get a pressure gauge!!!!!!!!!!!!!!!!!

[Glastron1987]

here it is...... get a pressure gauge!!!!!!!!!!!!!!!!!

Cool

[Glastron1987]

Or the poppet is leaking and the block can't get enough "head" pressure to fill completely.

Yeah, I think I'll make fixing that entirely a priority before another test.

[skialot2]

I think you have a blockage in the exhaust plate or in the block going from the exhaust plate to the cylinder cooling passages. Here is some pictures of how the water travels. The water goes up the water tube to the top of the block. It comes out here 526852 Then it goes into the exhaust plate here 526853 Comes out the exhaust plate and goes through these 2 sets of three little holes 526854 into the cylinder cooling passages 526855 Only the bottom 2 cylinders have the holes. Then into the top of the head past the thermostats and out the bottom. I think your problem will be with the three little holes going through the block into the cylinders. If it was a poppit problem, I don't think water would come out of either head.

[Glastron1987]

Very nice, thank you skialot2.

[Glastron1987]

I cleaned up the poppet plates with sandpaper on glass and a sanding block. There actually was one spot on one of the edges that looked suspicious and may have been causing the leaking. I ran the garden hose through the water tube to test, and it appears to be good now with no leaking.

Also, when running the garden hose through the water tube I noticed, as before, that water would come out of the port thermostat hole but not the starboard side ...until I blocked the port side. Then water would come out from the starboard side no problem. Is that normal?
526900526901

Also, around the garden hose, I assume there was leakage because it was not clamped to the water tube, but there was this constant stream behind the hose coming down from the midsection. It's tough to look up there to find the source, but anyone know what that could be? Seems like that may not be normal and could be robbing the system of some volume.526904

[Glastron1987]

Oh, now looking at the diagram again maybe that little stream is the cooling spray into the exhaust tubes. Hope so.

[OnPad]

Could be a combo of low pressure on your hose, and leaks. I think your extra hole under the poppet cover is leaking down the dump into the mid, and the holes that skialot mentioned, also dump into mid. Not a deal breaker, but enough of a leak that merc changed the design in order to help keep the block full at idle. The port thermostat is lower than starboard, hence you only get water out of the low one, until you block it off.

I would measure all cylinders, If good, replace bad piston/s, rod bolts, rod bearing/s. put thermostats back in, install a pressure gauge, and check pressure. If you still can't keep water in engine,... block the extra hole under the poppet, or remove powerhead, clean and replace the adapter plate gaskets. If still concerned about the starboard side, a tell tale from each thermostat housing is a option.

I believe this to be where water is leaking out of the bottom of the water column. This passage runs up under the poppet diaphragm, then out the dump, or if making lots of volume it helps open the poppet (possibly)....
The later design doesn't put water here until the block is full, getting its flow from a hose where your water pressure gauge was located, then to a fitting on the poppet cover. This is also a option you could retrofit.
526905

[Glastron1987]

Sure, if the poppet gives me any more trouble, I'll do the retrofit. Right now, it is looking good.

All cylinders except #1 look good. I'll try running one more time with a water pressure gauge applied and see what I get. Hopefully the cooling system will be OK now, then I'll proceed to break down the engine to repair that bad cylinder.

[skialot2]

You definitely need to plug the small hole in the poppet. If the small boss is open, the water is going from the intake dumping straight out the poppet. Never going through the cooling system. Put the hose on with the poppet cover off and see how much water shoots out. All that is missing the cooling system. https://www.screamandfly.com/attachment.php?attachmentid=524479&d=1694987138&thumb=1 Plugging the small hole should fix the cooling flow problem.

[pcrussell50]

You definitely need to plug the small hole in the poppet. If the small boss is open, the water is going from the intake dumping straight out the poppet. Never going through the cooling system. Put the hose on with the poppet cover off and see how much water shoots out. All that is missing the cooling system. https://www.screamandfly.com/attachment.php?attachmentid=524479&d=1694987138&thumb=1 Plugging the small hole should fix the cooling flow problem.

I can confirm this. One of my motors in this family has this “dogbone” style poppet, in which the small end is open. There is a hose barb on the small end, with a hose that joins up with the other hoses.

There is another style of poppet in this family of motors, in which the cavity for the small hole is present, but there is no opening there into the rest of the block. This kind of poppet only uses the big end. So it’s a circle instead of a dogbone.

-Peter

[Glastron1987]

The poppet isn't leaking anymore. That is good, but it looks like the exhaust system has been redesigned to exit the pee-hole. This keeps the water pressure from going to high; stays at around 1lb.:mad:

526946526947

[skialot2]

The poppet isn't leaking anymore. That is good, but it looks like the exhaust system has been redesigned to exit the pee-hole. This keeps the water pressure from going to high; stays at around 1lb.:mad:

526946526947

Unfortunately, you are going to have to pull the poppet cover again and plug the small side of the poppet. It is the original thermostat location. but it didn't work well so they moved the thermostats to the heads. They just left the boss there and didn't machine it for the thermostat. It needs to be plugged. It will cause a major loss of water pressure. The water from the water pump as going straight out the poppet without going through the motor.

Compression is getting into the cooling system. Probably the head gasket. I know you had the head off a couple of times. Did you replace the head gasket? They are not reuseable.

[tlwjkw]

Unfortunately, you are going to have to pull the poppet cover again and plug the small side of the poppet. It is the original thermostat location. but it didn't work well so they moved the thermostats to the heads. They just left the boss there and didn't machine it for the thermostat. It needs to be plugged. It will cause a major loss of water pressure. The water from the water pump as going straight out the poppet without going through the motor.

jus where in tha hell did you come up with this??? in your dreams??.. tha 2.0, 2.4, 2.5 has NEVER had a stat there............. not even for practice....

jan... tha few we had come thru tha shop "with that hole" and completely stock did not have any coolin' problems.. they were there for other reasons.........

[Glastron1987]

The poppet worked stock for at least a decade. I can tell because good compression ratings are written on the engine in 1999. So, I am doubting that the poppet is causing any issue right now.

The head gasket I had replaced, but yes, I did take the head off again so maybe I need to get another head gasket to try. Probably that is one advantage of the newer o-rings.

[tlwjkw]

you need ta look at tha head and tha deck surface.. you will need a good/accurate straight edge... we have reused head gaskets (ones that were never over heated) many times over tha years without a problem... tha o-rings, not so much...

but at tha same time we mostly used regular heads and gaskets on our motors (had ta deck tha blocks 'bout 40 thousands also) that originally had o-rings.. was to expensive to cut tha o-ring head ta get tha compressiopn we were lookin' for back then...

[skialot2]

jus where in tha hell did you come up with this??? in your dreams??.. tha 2.0, 2.4, 2.5 has NEVER had a stat there............. not even for practice....

jan... tha few we had come thru tha shop "with that hole" and completely stock did not have any coolin' problems.. they were there for other reasons.........



I heard that it is the original thermostat location from Jerry Hale. RCKID74 on this site. He was the project engineer for Mercury's (Black Max) 2 liter V6. You can read all about it on this site. It is in a sticky in "Outboard and Racing history" called "Merc V6 History" started by warrior74z in 2007. It's somewhere around 15-20 pages in. It's one of the best reads on this site. Lots of cool information.

[tlwjkw]

if they in fact did it never went into production............. tha very first 1976 175 2.0 V6 on tha market had stats in tha heads................

one thing 'bout tha 175"ski" is thats its built from tha only steel sleeve 2.4 motor (XR4 rotating assy and only with tha mariner badge) merc built.. it seems like it (steel sleeve 2.4) was just an experiment that used tha public for their R and D...... jmo.

[tlwjkw]

jus another note.. that "extra hole" seem ta appear at tha same time they realized they had a coolin' problem with tha water cooled rec/reg... they may have been lookin' for any way possible ta help with its (rec/reg) problem... jmo

[skialot2]

if they in fact did it never went into production............. tha very first 1976 175 2.0 V6 on tha market had stats in tha heads................

one thing 'bout tha 175"ski" is thats its built from tha only steel sleeve 2.4 motor (XR4 rotating assy and only with tha mariner badge) merc built.. it seems like it (steel sleeve 2.4) was just an experiment that used tha public for their D and D...... jmo.


That is exactly correct. They never went to production with the stat next to the poppet. That is why the thermostats in the heads look like an afterthought with the hoses. They were.

[tlwjkw]

jus that something doesn't add up with that hole (which seems synonymous with tha XR4 block), 2 and 4 bolt poppets.. everything had a two bolt with first gen blocks.. then came a 4 bolt for a time then back to two bolt and then tha 4 bolt again.. i know why tha 4 bolt with tha hose goin' to tha top of tha block came about (and has stayed around tha longest) and what its for but don't have a clue as to why tha other changes were made.... jus never questioned it... they either worked or they didn't.. if they didn't, replace with what ever it called for... jmo.

[Glastron1987]

Would putting a little antisieze on the head gasket be a no-no so that it comes off easier and keep in in better shape for reuse?

[tlwjkw]

dry.. justa a touch of 2 stroke oil on tha bolt threads..... did ya check tha surfaces for being flat?

[skialot2]

everything had a two bolt with first gen blocks..

I have a 1st gen. 1976 175 Mercury serial #4303839 It has a 4 bolt poppet with the hose barb. I guess could it have been changed.

[skialot2]

jus that something doesn't add up with that hole (which seems synonymous with tha XR4 block), 2 and 4 bolt poppets.. everything had a two bolt with first gen blocks.. then came a 4 bolt for a time then back to two bolt and then tha 4 bolt again.. i know why tha 4 bolt with tha hose goin' to tha top of tha block came about (and has stayed around tha longest) and what its for but don't have a clue as to why tha other changes were made.... jus never questioned it... they either worked or they didn't.. if they didn't, replace with what ever it called for... jmo.



Actually, I looked it up. according to the schematics the original 2.0L V175 first poppet design was a 4-bolt design. Part # 68729(#3) It has the hole for a nipple, but it is not shown. Probably uses a plug.

The second poppet design was a 2-bolt design. Part # 66563A1(#6) No hole for barb

The 3rd design went back to a 4-bolt design. Part # 14462A1(#17) Comes from the factory with the hose nipple.

https://cdn.boats.net/cdn-cgi/image/quality=50/MTA/d/f/OTM3MjA5OA-f3539cf8.png

[tlwjkw]

had it backwards but i'm old and no books ta read... so glad ya got all that straightened out.. some had a nipple and some didn't.. no mater what merc wasn't consistent with a "single" poppet design that would probably work in any of tha V6 blocks.. its like they were just experimenting with 'em.. but merc was famous for **** such as that back then...... even more so in tha hi perf. division............. jmo

still think tha reason for extra small hole is in some way connected to tha 40 amp rec/reg coolin' problems.. they were gettin' air pockets (normal) in tha system that caused tha problems with it... seems ta be thats when it showed up...........

[pcrussell50]

still think tha reason for extra small hole is in some way connected to tha 40 amp rec/reg coolin' problems.. they were gettin' air pockets (normal) in tha system that caused tha problems with it... seems ta be thats when it showed up...........

This^^^

I’m sooo glad my 1990 2.4/200 was converted by the previous owner to 16A/clamshell cowl. It does still have the extra hose from the small side of the 4-bolt poppet, up to the top. But no water cooled regulators.

-Peter

[Aaronhl]

exhaust in the pee hole or steam??

I wouldnt put anti seize anywhere near a head at risk of getting in the head bolt holes and i have found that to be a problem finding correct torque...

[pcrussell50]

exhaust in the pee hole or steam??

I wouldnt put anti seize anywhere near a head at risk of getting in the head bolt holes and i have found that to be a problem finding correct torque...

This is legit.

The purpose of torquing correctly is to get the specified preload on the head bolt. If you are torquing with unspecified lubricants or bolts not specified in the manual, you are then guessing on the preload.

That said, on my 2.4/200 I used anti-seize on the head bolts. I check it frequently for loosening. I understand that I have no way to know if it’s over torqued.

-Peter

[Glastron1987]

Took the head off again, and I saw no sign of water breach, and the head and block look flat. I seriously think there is some other issue causing such a severe loss of water pressure.

[skialot2]

Took the head off again, and I saw no sign of water breach, and the head and block look flat. I seriously think there is some other issue causing such a severe loss of water pressure.

All the water going through the small side of the poppet is also bypassing the pressure gauge. Pull the poppet cover. Put water to it and plug the small side of the poppet temporally even with your finger and check the pressure difference.

[tlwjkw]

that "extra hole" some are so concerned about will have nothing ta do with your problem.. its been there since tha very first day that motor was born... have you actually put this motor in tha water and under a load or is all this jus being done in tha driveway??.. did you get a gauge??? if so, where did ya plug it in?.. did you use a good straight edge to check those surfaces??? have you pulled tha divider plates to check for problems warped/cracked/gaskets there???... have you pulled tha power head to check tha adapter plates/gaskets???

jus how do you know its getting "hot"??? gauge (where ya gettin' tha reading?) and/or warning buzzer?.. this should have been asked a long time ago....

and yeah, that piston thing can cause all kinds a problems and still run (+ produce a knock sound).... until it self destructs.

[tlwjkw]

This^^^

I’m sooo glad my 1990 2.4/200 was converted by the previous owner to 16A/clamshell cowl. It does still have the extra hose from the small side of the 4-bolt poppet, up to the top. But no water cooled regulators.

-Peter

yeah, they kept tha extra hose after tha water cooled crap went away.. it did help with tha balance of tha overall coolin' system... it lasted tha complete life cycle of tha 2.5....

[Glastron1987]

that "extra hole" some are so concerned about will have nothing ta do with your problem.. its been there since tha very first day that motor was born... have you actually put this motor in tha water and under a load or is all this jus being done in tha driveway??.. did you get a gauge??? if so, where did ya plug it in?.. did you use a good straight edge to check those surfaces??? have you pulled tha divider plates to check for problems warped/cracked/gaskets there???... have you pulled tha power head to check tha adapter plates/gaskets???

jus how do you know its getting "hot"??? gauge (where ya gettin' tha reading?) and/or warning buzzer?.. this should have been asked a long time ago....

and yeah, that piston thing can cause all kinds a problems and still run (+ produce a knock sound).... until it self destructs.


All driveway so far.

Yes, I used a pressure gauge connected to the fitting on the top of the motor that read about 1 psi.

Used infrared temp gauge to determine overheating. Usually, I'd shut the motor down before the buzzer but it did trigger once.

I'll double check my straight edges, but I used 2 of them with no reason to think that they are bad.

Have not checked the divider plates or pulled the power head yet. I wanted to try the easy stuff first.

[Glastron1987]

looks like you have one of tha very first of tha water cooled reg/rect. motors... first '89's didn't have tha hose from top down to tha poppet.. that came later in tha year model ('89) ta help keep tha reg/rec cool.. yours is for an added water pressure gauge....

Oh, that sounds like an extra complication.

[tlwjkw]

1 psi at tha top of tha motor is not good.. thats a direct path (look at tha dia.) from tha pump without any interference or change of direction except tha tube, grommet in tha bottom plate and tha plates themselves.... no mater.. if ya gonna fix tha one hole its gotta come off and apart anyway unless ya planin' ona tryin for tha "cheap" which usually fails eventually sooner or later... your choice.... jmo.

jus thought i'd add this little tid bit.. tha more ya fool with it chasin' this over heart problem tha more ya gonna make tha motor more broke than it is now so ya you need ta get off tha over heat thing and get with fixin' tha thing thats apparent.. you should find tha over heat problem along tha way.. justa suggestion while ya still have something that can be fixed with a reasonable amount of $$$.. if it sticks a rod through tha block tha over heat problem will go away also... jus somethin' ta think about.............

[tlwjkw]

Oh, that sounds like an extra complication.

it "was".. merc fixed it by eliminating tha water cooled rec/reg after a short run...

[Glastron1987]

Yeah, I'll focus on the rod now.

[tlwjkw]

good idea.. jus remember that on assy. "everything clean, clean, clean".. did i mention clean?

good luck is with ya.

might wanna get tha injectors checked/cleaned while ya have it down.. cheap insurance.

[Aaronhl]

I cleaned up the poppet plates with sandpaper on glass and a sanding block. There actually was one spot on one of the edges that looked suspicious and may have been causing the leaking. I ran the garden hose through the water tube to test, and it appears to be good now with no leaking.

Also, when running the garden hose through the water tube I noticed, as before, that water would come out of the port thermostat hole but not the starboard side ...until I blocked the port side. Then water would come out from the starboard side no problem. Is that normal?
526900526901

Also, around the garden hose, I assume there was leakage because it was not clamped to the water tube, but there was this constant stream behind the hose coming down from the midsection. It's tough to look up there to find the source, but anyone know what that could be? Seems like that may not be normal and could be robbing the system of some volume.526904

what psi do you get with garden hose connected and everything else bolted on?

[XstreamVking]

No mention seen of the rubber grommet that the plunger/spring assembly seats on in the block. Check to see if it's missing or torn?

[Glastron1987]

what psi do you get with garden hose connected and everything else bolted on?

I didn't try that. I'd have to take the LU off again to try that, not to mention put the head back on. The 1psi was with it running.

[Glastron1987]

No mention seen of the rubber grommet that the plunger/spring assembly seats on in the block. Check to see if it's missing or torn?

The grommet, spring and plunger were all replaced brand new.

[Aaronhl]

The grommet, spring and plunger were all replaced brand new.

There is also the plastic spacer that you press (hammer) into the block but i am not sure that is causing the overheat issue

[pcrussell50]

There is also the plastic spacer that you press (hammer) into the block but i am not sure that is causing the overheat issue

valid point. We learned in one of the bridge port threads that since the BP didn’t come with a poppet, if you wanted to add one, you had to machine or hand-fit the hard plastic spacer into the recess in the block where it would normally go if it were a fish motor and not a BP.

I doubt this would apply to the Ski, but you never know. The hard plastic disc should be in place with the four staking holes around it. Or is it three staking holes?

-Peter

[XstreamVking]

That's the "grommet" part I was thinking of. Have had them crack and fail causing low pressure, and over heat.

[pcrussell50]

That's the "grommet" part I was thinking of. Have had them crack and fail causing low pressure, and over heat.

Darn, that would be a horrible way to lose a cherished engine. You could be a good maintainer and a gentle, non-abusive driver and still lose your motor. :(

-Peter

[XstreamVking]

Never burned one up. Yet... Having the right gauges is crucial. Pressure AND temp. I have a sender in each cyl. head with a selector switch before the gauge on 2 of my boats.

[Glastron1987]

There is also the plastic spacer that you press (hammer) into the block but i am not sure that is causing the overheat issue

I left that spacer alone. It looked OK, and I figured I could get into a mess trying to remove it.

[Glastron1987]

Hope all that (i.e. XRI/EFI) luggage I had to remove is worth it compared to a carb engine Alos, I could not remove the connecting rod cap and bearing from the front of the engine like I did on a 150 a while back. In any case I got it out from the back. The only possibly strange thing I see now is the space between the connecting rod and the piston. Not sure if that is normal or could cause some slap.

527113

[OnPad]

That's normal for a bottom guide setup.

[Glastron1987]

That's normal for a bottom guide setup.

What is a bottom guide setup?

[OnPad]

The v6 mercs used the crank to center the rod before 1991, this is bottom guide. After 91 they centered the rod with the piston, referred to as top guide.

[Glastron1987]

The v6 mercs used the crank to center the rod before 1991, this is bottom guide. After 91 they centered the rod with the piston, referred to as top guide.

Thanks, interesting. That's a new one for me.

[Glastron1987]

So what's the trick to getting those pesky piston pin retainers back in? My fingers and small screwdrivers don't seem to do it.

[OnPad]

A pair of needle nose pliers and bloody fingers, unless you have the special tool, but kinda hard to find as they are made to the specific wrist pin size. Do a search for piston circlip installation tool. Maybe you find the correct size ,or get a idea how to make your own..( which could be done out of a old scrap piston, and pin.)

[tlwjkw]

for cir clip install (and wrist pin)... it works with wrist pin install also.. it will keep tha shims in place when ya push tha pin in.... look it and tha parts over and you should be able ta tell how that part will work.. jus makes it a tad easier...

part number 91-77109A 3... pricey but worth every penny... jmo

[Glastron1987]

A pair of needle nose pliers and bloody fingers, unless you have the special tool, but kinda hard to find as they are made to the specific wrist pin size. Do a search for piston circlip installation tool. Maybe you find the correct size ,or get a idea how to make your own..( which could be done out of a old scrap piston, and pin.)

Well, I have an old piston and pin. Not sure what mods I'd have to make though. Have to think about that.

[Glastron1987]

for cir clip install (and wrist pin)... it works with wrist pin install also.. it will keep tha shims in place when ya push tha pin in.... look it and tha parts over and you should be able ta tell how that part will work.. jus makes it a tad easier...

part number 91-77109A 3... pricey but worth every penny... jmo

Thought getting the pin in with those needle bearings would be tricky, but with the assembly grease it went pretty easily. I've done clips before but don't remember how tricky it can be. I'll look at that tool. Yeah pricey. Hope that works for the 2.4 as well as the 2.5 that is indicated.

[tlwjkw]

all 2.0, 2.4, 2.5.....

it will pay for itself by savin' cost of neosporin and band-aids...........

[OnPad]

Well, I have an old piston and pin. Not sure what mods I'd have to make though. Have to think about that.

You would have to cut the scrap piston up, use one side of the wrist pin boss. With a die grinder you shape the side that takes the clip into a funnel, the other end can be shaped to fit the new piston. You also would have to take a little material off the scrap wrist pin, that you use to push the circlip through your homemade tool into the new piston. If you take enough diameter off the pin (slides in and out the new piston easily), it now works to hold your bearings and shims while you install the new pin.
527434 527435

[Glastron1987]

You would have to cut the scrap piston up, use one side of the wrist pin boss. With a die grinder you shape the side that takes the clip into a funnel, the other end can be shaped to fit the new piston. You also would have to take a little material off the scrap wrist pin, that you use to push the circlip through your homemade tool into the new piston. If you take enough diameter off the pin (slides in and out the new piston easily), it now works to hold your bearings and shims while you install the new pin.
527434 527435

Wow, you just scared me into ordering that pricey tool!

[pcrussell50]

Wow, you just scared me into ordering that pricey tool!

LOL, I was as thinking the same thing. ;)

-Peter

[Glastron1987]

Well, I have this nice tool now but can't quite figure out how to use it. I think I have to somehow get the retainer compressed and inside the tubular part of the tool, then push it in with the other part. Does that sound right?

527677

[OnPad]

Your on right track. Seperate the tool into two pieces. The clip goes inside the hollow tube, the piece with the ball on it goes on top of the clip, push the clip towards the end of the tool without pushing it out. Firmly hold the coned end up against the wrist pin slot, and give it a whack, preferably with the piston well supported in a cradle.

[Glastron1987]

Your on right track. Seperate the tool into two pieces. The clip goes inside the hollow tube, the piece with the ball on it goes on top of the clip, push the clip towards the end of the tool without pushing it out. Firmly hold the coned end up against the wrist pin slot, and give it a whack, preferably with the piston well supported in a cradle.

Got it. There is a minor trick getting it into the hollow tube, but it's pretty easy after doing it once. Just straight in with a screwdriver seemed to work fine. Then it was easy with a small whack on the ball end. Yeah, that tool help a LOT.

[Glastron1987]

Honed the cylinder, installed a new piston and rings. The old one was very warn and had a stuck ring. Compression in all cylinders is 120-135. Except this one is about 110:527912

[skialot2]

Honed the cylinder, installed a new piston and rings. The old one was very warn and had a stuck ring. Compression in all cylinders is 120-135. Except this one is about 110:527912


It should run fine with 110 compression. Did you measure the bore? Does it still have the knock?

[Glastron1987]

It should run fine with 110 compression. Did you measure the bore? Does it still have the knock?

I did not have a good way to measure the bore.

After I get it together and run it, I'll know about the knock, but by hand and with the starter, it seems really smooth. Also, the piston does not rock like it did before.

I'm excited that it may be OK, but won't know until I try.

[Glastron1987]

Putting my XRI back together and forgot how this clump of ground wires is supposed to be secured. Can anyone verify if I got it right?

A wire comes from the bottom of the starter (side photo) to the starboard screw of the water sensor module (front photo). Then a wire goes from there to the bottom starboard ECU screw, and that connects to a wire that comes from the back of the water sensor module.
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[OnPad]

Right or wrong, this is how mine is setup. Looks like I grounded from the ecu to the face of the injector plate, in order to take the rubber av mounts out of the equation. I also deleted the water alarm module. If memory serves, it no longer works with a oil injection delete.
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[Glastron1987]

Right or wrong, this is how mine is setup. Looks like I grounded from the ecu to the face of the injector plate, in order to take the rubber av mounts out of the equation. I also deleted the water alarm module. If memory serves, it no longer works with a oil injection delete.


So thanks. Since, at least for now, I do still have the oil injection and the water sensor module, it looks like securing the wire from the bottom of the starter to my starboard water sensor module is equivalent to the way you have it attached to the top as it ends up in the same plate.

I was thinking that the wire coming from behind was from the water sensor module, but since you still have one, I'll have to double check what that is ... and maybe I should bring that down to the water alarm module screw too. Looks like it may have been like that based on the bend in the wire. Thanks.

[Glastron1987]

So, I got the engine back together and ran it on the muffs. This time it actually peed at least some. The knocking noise is not totally eliminated but is much better. I figure the next step is to rig on my boat and do a real trial run.

Question ...if I find out it's not good enough, I'll probably be looking for a new power head with all good cylinders and pistons and just replace that to work with this XRI system. Would I need another 2.4 power head, or could a 2.0 or 2.5 power head work as well?

[OnPad]

For the most part they are interchangeable. I think that the reed plate might have a little different bolt pattern that could be modified with the elongation of 2 holes to fit a newer block. The exhaust cover/divider, and coil mounts likely need to be updated. The voltage regulator/rectifier also needs a update to fit the new exhaust cover/divider. The cowl might work, if it's not too narrow. I put a 2.5 liter gasket on a 88/2.4 adapter plate so I think your good there, if it was a older 2.0, or 2.4, you would need the adapter plates.
Not 100% positive on all this, but it's what I've noticed in my hoard, and read over the years.