1978 Mercury 140 TOP Overheating

[stephenspann27]

This motor has been setting off the overheat alarm sooner and sooner. I can only go about 5 minutes at cruise before it overheats. I took the water jacket cover off and didn't find any heavy corrosion or blockage. The water pump is new, and I get a strong stream out of the pisser at all times. I read that on some outboards you can have gasket failures at the powerhead/mid section that allows hot exhaust to heat up and pressurize the incoming water. I am seeing steam rolling off the midsection and I'm wondering if that's my problem. I've never had this motor apart, so I'm not sure where the copper tube ends. This motor has no thermostat or poppet valve to my knowledge. I am close to just parting this motor out.

[milkdud]

You have an overheat alarm on a 1978 140? Didn't know they had one......

Have you actually put your hand on the powerhead to feel if it is actually hot? Is it bogging down like its hot or is the alarm just going off??

Does this motor happen to have the AUTO BLEND oil premixer in used? That could possibly have an alarm in it if the oil is low.


If it truly is hot then it can be a host of things. But lets make sure it truly is getting hot first.


C

[stephenspann27]

I added the overheat alarm. There was a pipe plug in the cylinder block cover that you can remove an insert a sensor. The motor is truly getting hot. The water coming out of the pisser is blazing hot, I can also see steam coming off of the mid section. The motor will also start to run rough as it gets hot. This is a premix motor. The overheating is consistent, if I run above 19mph for over 5 minutes it will start to overheat, then if I slow down and troll a while the buzzer will go off. I know water is circulating well, and pressure is good. I'm thinking there has to be exhaust getting into the water, or some major carbon build up in the exhaust area, or on the pistons themselves. I ran it out of gas a month or so ago, and it started clattering really bad and sort of "ran away' on carbon. I have put so much time an money into this motor it is unreal. I have decided to pull it off my boat, my only motive to fix it is so I can sell it whole instead of for parts. The motor went from overheating once every few weekends, which was usually after a long full speed run, then shutting the motor off without letting it idle a minute, then to overheating once every other weekend, to now overheating constantly.

[Dave Strong]

Exhaust plugged? Getting lots of water coming out of the exhaust reliefs in the mid section?

Dave

[stephenspann27]

Dave, I hadn't thought about that. Where do you think it would be plugged? The ports in the midsection? It's a shame this motor doesn't have a removable head, I'd like to look at the top of the pistons. If I take the exhaust plate off can I see them through a port or something? I'm not that famliar with crossflow 2Ts.

[milkdud]

If this is a 1978 140 then it should have a distributor. That makes it pretty easy to pop off the center transfer port cover and look at the pistons if you want to. You will get to see the intake side. Also at that point you can shine a light into the cyl and look thru the spark plug hole. cyl 3/4 cover is pretty easy to get off. 1/2 and 5/6 are much harder because they are covered with stuff.


Now the powerhead lifts off when you taker he nuts off the 8 powerhead bolts under the beauty valance.

I think the pisser on that motor comes from the top of the block right? Put a clear hose on it and run it and watch it dump out. If its got good flow out a 1/4 inch hose without bubbles then Im not sure.

But if you see lots of bubbles or you the flow is not very good then I bet you have a restriction or bad gasket somewhere.

The pisser in its stock form restricts down to like 1/8th inch so even low flow will look good because its forced out such a small hole.


What is very common is when the old impeller pump looses a few blades and they migrate up to the powerhead and block water entering the powerhead. The block can still fill up with water, but not enough flow to cool it.

The water tube can be incorrectly installed dumping water flow.

The impeller itself can be junk. Ive seen some spin on the hub.

Does it take awhile before the water comes out the pisser, or when first started does it come out within a few seconds?

C

[stephenspann27]

Lot's of info there Milkdud, thanks. It does have a distributor. I've been hesitant to remove the exhaust plates because I know several bolts will snap off. I snapped 4 off when removing the head plate. I have run this motor into the mud and sand several times, I run my boat in a lot of shallow areas. When I had the cylinder plate off, there was a small amount of sand in there. The pisser hose comes off the top of the block, so the whole block has to be full and pressurized for it to pee. I am getting a really strong stream. The impellar I removed at the start of the season had not fallen apart, it was just really worn. With the new impellar I get a stream a lot sooner, maybe 5 seconds. The old impellar barley put anything out at idle at all, and the motor did not seem to run hot back then (I didn't have a working alarm at the time so it's hard to know). The cylinder plate started leaking when I put the new impellar in, I guess it is a little warped. The leaks were very small. As the overheating started getting worse, I figured I better pull the plate and look for corrosion, then take the opportunity to replace the gasket and fix the leaks at the plate. I ended up having to use a bunch of RTV on each side of the new gasket in order to get a seal around the spark plug area. Now that the plate is not leaking, I didn't find any corrosion, etc, I am scratching my head. I have had the lower unit off three times with no changes to the overheating.
I know a lot of people say that running your motor too high can cause over heating. On one hand, this seems like my issue, because I am running a 20'' shaft motor, on a boat designed for a 25''. However, I am using a 9'' static setback plate, mounted really low on the transom to get the motor down to what I think is the proper height. I have hung off the back of the boat while on plane and looked at where the AV plate is riding, it is just above the surface. The pisser stream to steady and strong while on plate. I hadn't thought about there being air in it thought. It just doesn't make sense that it wasn't overheating before, it is now, and haven't changed the height of the motor. Everytime something goes wrong on this motor I think, "I'll just fix this one other issue.. then it'll be fine." then something else goes wrong. I am tempted to finally draw the line and cut my losses.

[stephenspann27]

Here are some photos of the cylinder plate. The corroded are I have the pic stuck in goes nowhere. I cleaned all of the corrosion off the plate.

[milkdud]

Im talking about opposite side from the exhaust side. There are 3 transfer/intake covers that have fins on them. They usually come off pretty easy if you want to look in the bore/piston there on the intake side of the pistons.

When you look at the spark plugs after running did you see any hint of moisture? Were any of the spark plugs super clean vs having some carbon build up on them? If it has an internal water leak on the exhaust plate usually it will steam clean that cyl and sometimes it can cause overheating. If your plugs look the same and no water droplets or moisture present I would not take the exhaust cover off. It can be a pain.

It sounds like your looking at everything.

If you have good water flow, I would start to wonder about your timing and fuel mix. If its leaning out some how it will get warm and if its got too much advance it will heat up if your lugging it.


The overheating is consistent, if I run above 19mph for over 5 minutes it will start to overheat, then if I slow down and troll a while the buzzer will go off.


I am running a 20'' shaft motor, on a boat designed for a 25''

If it cools fine when not planed out, but overheats running fast you may be too high... Do you have any pictures of it on the boat showing prop height.

C

[stephenspann27]

I have actually seen what looks like moisture on the plugs. Last year I plugged this motor up with silt and I'm wondering if I warped something badly then (it got hot), and the problem has gotten progressively worse. I haven't looked really hard at any of the plugs, but I know none of them have looked very carboned up, but I wouldn't say any of them looked excessively clean either. I am looking for a side profile photo of the boat with the motor trimmed down. I tried to follow the rule of using a straight edge off the bottom of the boat, and measureing up to the AV plate. I think it' son the high side but I don't think it's bad enough to be causing these problems. Speaking timing, someone had the motor maximum advanced. It was at 24 degrees at idle. It's supposed to be at 4 degrees. I retarted the timing and that made the engine run a million times better. This was before I had the overheating issues. Pics in next post.

[stephenspann27]

305611305612s

[stephenspann27]

I believe these are the transfer port covers you are talking about.

[milkdud]

Best I can tell form that angles is your height look ok ish. I would not think its your problem, but every boat throws water differently. If you got water coming out your tell tail at all times then I will assume it not too high.

Now if you have noticed water droplets on your plugs, then you got a problem. If its showing up you either have a inner exhaust cover leak, or a bottom main crank seal leak. Can you remember what cyl or cyls the water showed up on?

Now that seems to be a pretty big boat! What pitch its that prop? What RPM are you getting at WOT?

C

[stephenspann27]

Agreed, my current boat is too big and heavy for this motor. My parents owned a 1977 Chrysler Funster since 1979. The Chrysler 105 gave up somewhere in the late 1990s. My dad bought a deck boat with this 140hp merc on it and swapped it onto the funster. I brought the boat out of mothballs in around 2003 after it sat for 4 or 5 years. I did some work to the hull and cleaned the carbs. After I moved out of the house and went to College, my dad sold the boat to a friend. That friend took the boat to a mechanic for a "tune up." The mechanic replaced some bad floats, which was good, but he also adjusted the the timing while on the water, with no timing light, which is why it was max advanced. The motor quit on my dad's friend one day and he just gave the whole boat back to my dad for free. My dad replaced the coil and got it running. I brought the boat down to Katy, Tx with me last year and ran it trouble free. The old funster was falling apart though. transom rotted, floor rotted. I found my 1998 19' Sunbird Fish and Ski on Craigslist. No motor, no upholstery. I paid $900 for it. A tire blew out on the trailer taking it home.. so $300 on new wheels and tires. Then I replaced the leaf springs. I replaced all the upholstery. I quickly found out that my motor was to short for the boat so I bought the setback plate and drilled new holes ($350). While I had the mercury on the stand, I replaced the timing belt (that runs the disty), the water pump, and all the seals in the lower unit. The motor really struggled to get this big boat on plane, fixing the timing helped a great deal. I'm running a 17p prop right now, and with 6 people in the boat it's hard to get on plane. I can run 33mph, no sure what RPM, I don't have a working tach. If I were to keep this motor I would drop down to a 15p prop. I also lost reverse a couple weekends after fitting the motor to my new boat. I ordered a new sliding gear dog, and a new reverse gear. When i took the gear case apart I found all kinds of carnage. A piece of the shift cam sheered off and floated around and damaged the pinion gear badly. I replaced a lot of stuff in the lower unit, and I'm good there now. I also had to replaced two of the carb floats. Is anyone still reading this? :-P Sadly I am leaving a lot out.

[stephenspann27]

picsss

[stephenspann27]

I think you are the right track about the water getting in the cylinder. I have seen steam coming out of the exhaust ports. That would mean there is a bad gasket, or warped exhaust plate?

[milkdud]

I don't think its a water problem just yet. Steam will come out those two exhaust ports. thats not abnormal

What is killing you is that boat/ prop combo.

I ran the quick math and your only getting 4369 RPM at that speed. THAT IS KILLER.

This motor should run 5800 MINIMUM. Closer to 6000 RPM WOT is preferred.

Your lugging the tar out of that motor and its probably detonating and overheating.

I bet if you found a 13 pitch prop you would be in the ball park and still run about 32 mph.

the math shows 13 pitch 33 mph running 5800 RPM.

That motor needs to be timed no more that 19 deg BTDC also. Expecially on a big boat.

I would be interested to see how bad your piston tops look after lugging it that much.

Conrad

[stephenspann27]

I haven't actually checked the max timing, I just corrected the base timing. I need to get a tach hooked up so I can see what RPM I'm pulling. I checked the compression a month or so ago and it was something like 110, 115, 118, 105, 90, 100. You can tell the motor is under a huge load behind this boat by the tone it makes. I believe the base timing is at 4 degrees.

[milkdud]

My calculator is pretty close. Your lugging the tar out of that motor. Those inline 6's self destruct loaded down in that RPM range.

Id like to see compression above 125 per hole. 135 is better.

Im guessing you lugged it enough that you detonated the crap out of the piston and your compression is down.

Its sad to say you probably need 6 new pistons and rings :(

That motor in good shape and a 13 pitch prop would push that boat decent. But lugging it Im sorry to say has shortened it life span considerably.

A V-6 would push that bot much much better, especially once your loaded down with friends/beer.

Looks like a nice boat, you could rebuild the L6, but spending that money on a V-6 would probably make you happier in the long run.
Conrad

My dad had a 21 foot fishing boat with a 135 optimal 2.5 L V-6 outboard. That 135 V-6 will destroy my 150 hp inline 6 any day of the week. The V-6 is so superior its not even funny. 1.6L vs 2.5 L makes a lot of difference. Plus the 150 is more like 125 hp at the prop, similar to your 140. I bet your boat is rated for 150-200 hp.?

[milkdud]

You could probably rebuild that thing with 6 new pistons for 600-1000 depending if you have to bore it up.

or pony up and get a V-6. I hate saying that because I only run TOP's but I run much smaller boats.

I you decide to go V-6 Im guessing 2k is the minimum for anything decent. Others would know better than me.
C

[Capt.Insane-o]

II checked the compression a month or so ago and it was something like 110, 115, 118, 105, 90, 100. Y.

It's toasted, don't spend another penny on it. You need a v-6.

[stephenspann27]

I really appreciate all the information. I really thought the I6's were great motors, they are certainly really light. I guess the V6's make so much more power because of the displacement? I would think the I6 should make pretty good torque for it's size. I've read that the crossflow motors idle better than loopers because they have such a heavy rotating assembly. The compression was about 10psi higher last year on all cylinders, so i agree it's probably damaged.
Just got off the phone with my dad, who almost never gives up on a project, and he is suggesting I cut my losses on this engine and get something with more power, and the correct shaft length. This boat came with OMC engines 115-200hp. It had a 150 ocean pro on it originally. I have the OMC wiring harness and controls, and my gauges are all OMC, so I'm tempted to go back with an OMC engine. I'm hesitant to buy another carbed motor, but I don't want a Fitch, and the Bombardier FI engines are pricey. I've done a lot of research on 2014 engines, and the 175 Suzuki is the most attractive. It the same as the 150hp, but with VVT. I have also considered post 1992 FI Mercuries, but I wouldn't be able to troubleshoot at home, and injector issues can be as bad as carb issues. This boat, with a appropriate age and size motor on it is probably worth $6,500. Even though I only paid $900 for the hull, and already had a motor, I still have $4k in this thing. $1,750 of that was upholstery, the rest were motor and trailer parts. It doesn't make a lot of financial sense to put a $14k motor on a $6,500 boat, but I understand that's just part of boating. I would really like to spend some time making improvements to the hull it'self, the wiring etc, but I've been spending all the time trying to keep the thing running, which is what makes a modern 4 stroke with a 6 year warranty to attractive.

[milkdud]

What does the capacity plate say for HP limit? 175?

The I6's are great motors for what they were designed to do. You just have too much boat for a I6 to work with. Plus you killed it lugging it plain and simple. If you just had a tach and knew enough to get it up to 5800 RPM you probably could have made it work ok, but it still is weak for that boat. Ive had my share of money pits and losses so it happens to all.

Yes the V-6's are just superior in most every way. Exhaust, Intake, Loop Charged. Electronics Displacment.

There seem to be many 2.5 mercury 25 inch motors out there in the 2500-4000k $ range. Lots of times they will come with controls and a tach is really all you need and they can be had of as little as 50 bucks on ebay.

Your motor is really not worth much. But part it out. TRIM, LOWER UNIT, ELECTRONICS and move on. Much of the rest is good for scrap.

Conrad

[milkdud]

PS if I were you I would post a question in the General Forum . Put a picture of your boat and its specs and let people recommend a good V-6 for you. You will get all sorts of points of view, but you can sort thru that and make a good decision.

I don't know much about V-6's, so my help stops here.

C

[stephenspann27]

Milkdud, I really appreciate all the advice and time you spent helping me out!

P.S. The coast guard plate shows a max of 200hp.

[milkdud]

Good luck to you. You will have lots of good options. You will like the V-6.

[stephenspann27]

Did some reading tonight on compression numbers. I don't think mine are alarmingly low, I would agree they indicate wear, or rings stuck, but the #'s don't see too far off. I am after all able to run 33mph in a 19' 2,600lb boat with a full tank of gas and 3 people. I think before I start parting the motor out I'm going to get a tac hooked up and see what my RPM is at top speed. if it's in the 4k's like you say, i'll swap the prop and see if the overheating goes away. I have also noticed that when I run the motor on the water hose that it will leave a black stain on my driveway of sludge that has come out of the exhaust. I think the motor has some old carbon in it for sure that is causing problems.

compression thread: http://forums.iboats.com/forum/engine-repair-and-maintenance/mercury-mariner-outboards/600166-compression-variance-1978-mercury-1150-6-cylinder

[dompie99]

I had a 140 V4 OMC on a Glastron 16 feet way back in 1980s and it ran close to 65 mph with the engine lifted 3 inches and a chopper 25 inches .......|if it might help you to fix an objective as to where you could be FLYING AND SCREAMING.

[stephenspann27]

This motor was pretty fun and peppy when it was on the 17' Chrysler Funster. When I took that hull to scrap it weighed 950lbs.

[milkdud]

110, 115, 118, 105, 90, 100.

This is low. even if they all were @ 118, its still low. Not sure who would say this is not low for an inline?

If your prop truly is 17 then by all means double check what I am telling you.

Have you pulled a transfer port cover and looked in there yet?

That will tell you a lot. Its like 8 1/4 inch bolts and you can look at the piston. I bet your deflectors are ate off.

Look in there and post a picture of the top of the piston and the side of the piston as it goes by the ports.

C

[stephenspann27]

Will I need new gaskets before I pull the covers off?

[milkdud]

Will I need new gaskets before I pull the covers off?

Yes possibly you will. They stick pretty good if they have been on for a long time.

If it just breaks in one corner lots of times I will just use gasket maker to seal that broken part.


You have a 50-50 shot. The gasket is one piece for all 6 cyls by the way.

If your not going to rebuild it, don't bother. But it you really want to try and rebuild it , Id look in there before I decided anything. The gasket was like 6 bucks last time I got one.

Bottom line I think its toast. :)

have a good one.

Conrad

[stephenspann27]

It very well could be, and I'm curious like you. I'll get a tach hooked up and take it out again and see what RPM's I can pull. I'm sure i'll end up taking those covers off as well. I'll post pics when i do.

[stephenspann27]

Hoping to get a tach hooked up tomorrow and test on saturday. I came accross this prop guide, and it shows that a 17p prop would be ok for my length and weight bought. We'll see what the tach says.

http://www.maxrules.com/oldmercs/Propellers/Props/21.pdf

[stephenspann27]

I haven't been able to get the tach to work yet, my onboard tack doesn't work at all, the tach from my old boat reads really low, so does my 1970's sears tool. I took some video of the pee stream and of the infrared temps on each cylinder. Interestingly the pee stream gets more erratic at higher rpm. I'm going to be taking the infrared thermometer with me tomorrow.

https://www.youtube.com/watch?v=Mo2Qp-yFH1U

https://www.youtube.com/watch?v=O1VSqzKG9Lg

[milkdud]

Interestingly the pee stream gets more erratic at higher rpm.

On a hose it can do this if there is not enough water going into the lower unit.

C

[stephenspann27]

milkdud, I watched some other peoples videos and noticed the same thing. I'm headed out to do some early teal hunting. I'll let you guys know what the temps are.
Thanks

[stephenspann27]

I checked the engine with my temp gun when the overheat buzzer went off. The hottest I saw was 170 degrees on one cylinder, the rest were close to that or less. I got the boat up to 37mph today with a tail wind.

[Dave Strong]

And how many rpm? If your lugging it going to get hot.

Dave

[stephenspann27]

I still haven't been able to get a tach working. The motor sounds wide open though. This motor came off a 20' deck boat so my boat should be around the same weight as that. I'm going to order a tach.

[Dave Strong]

I still haven't been able to get a tach working. The motor sounds wide open though. This motor came off a 20' deck boat so my boat should be around the same weight as that. I'm going to order a tach.

Put the mofor on a boat it should be on. Then deal with it., you are trying to make a boat work with way less HP than it needs. You will kill a good motor trying to to get ahead. You need to start over. You will kill that motor if you keep going the way you are.

Dave

[milkdud]

http://www.ebay.com/itm/FARIA-TC9011B-EURO-BLACK-BLACK-MERCURY-OUTBOARD-BOAT-TACHOMETER-GAUGE-/141160007214?pt=Boat_Parts_Accessories_Gear&hash=item20ddcac62e&vxp=mtr

Any 12 pole tach will run off your charging stator. Pretty easy to hook up. I use the one above. Running without a tach is like reading the newspaper blindfolded in a dark room.

Like I said before, the prop calculator is pretty accurate. If you know your speed and pitch I can tell you your RPM pretty closely.

C

[Slimm]

I have followed this post a little and I am going to put my 2¢ in for whatever it's worth. I personally think your boat is a little on the heavy side for that old engine. Your boat is a 1998 weighing in around 2500-2600 pounds. That 1978 is rated 140hp at the crank which puts it around 119-120hp at the prop. Even though 120hp may be enough to move your boat at an acceptable speed if it had a 1998 engine or one of that era, the old inline engines just didn't have the power that the newer v-6 engines have. That old inline needs to be ran where it can jump on plane and rev easily and quickly to the upper end of the RPM band. If you load it down and lug it then you are (in my opinion) killing way faster than you need to.

I have had several of those inlines from 1974 through 1978 and from 115 to 150 hp. They just won't live long on a heavy boat being lugged around. I am sorry if that is not what you want to hear and I understand the frustration of trying to make it work and not wanting to face repowering. I have been there, recently as a matter of fact. After I spent thousands of dollars trying to make my old inline do what I 'knew' it should do in my mind, I finally accepted fate and sold my inlines ( I had two at the time) and repowered with a newer v-6 and I wish I would have done it years ago...there is NO comparison, much more power, more dependable, less expensive to maintain, and better fuel mileage from an engine with approximately twice the power.

I would like to suggest that you take a few minutes and evaluate your situation and see if you can sell your engine to someone who has a need or desire for one either for a current project or just to stick in a corner and collect dust for the nostalgia of having an old inline as they are getting more and more difficult to find. Sell that thing for a fair price and hit craiigslist and the newspaper adds for something a little newer. Hell I have a friend here who has a super nice Mercury 2.4 chrome bore engine for sale, top of cowling to bottom of skeg with about 125lbs compression across all 6 for sale asking $1500 for everything. That would push your boat better and most likely be a lot more efficient on fuel which would eventually pay for itself.

Again, not meaning to offend or upset anyone just offering an opinion.


Slimm

[stephenspann27]

Current prop is quicksilver 48-72764A5 17p. 13-1/4” x 17p

[stephenspann27]

Slimm, thanks for the input. Don't worry about offense I have thick skin. I agree with you guys that I'm asking a lot of this motor I am just having a hard time deciding what direction to go when it comes to replacing it.. used carbed v6, used EFI V6.. or brand new 4t suzuki 175. One thing you guys might be able to help me out on is telling me how those carbed V6's act on the water. My inline will start with a bump of the starter a lot of the time. However, it is hot.. or something is out of wake whatever reason, I have to use the neutral overide to get the thing to start. Once it starts, I have to blow the motor out a bit before putting it in gear, or it will die when it goes into gear. Once you get past that, the motor runs fine until you shut it off again. I figured this is just typical 2 stroke carbed behaviour, which is why I'm hesitant to pick up another carbed 2 stroke. If OMC loopers, or merc v6's don't do this then i'd be more motived to swap one onto my boat. Something else I'm dealing with that has sort of talking me out of buying a new motor, is foam stringer delamination. I thought my boat had wood or composite strings, and the foam I saw was just for floatation. It turns out the whole freggin stringer is foam, it is seperated from the hull, which has resulted in stress cracks on my chine. I'm trying to get some advice on how to proceed with fixing that, no way am I de-capping this sucker.

Pictures are on the next page

[stephenspann27]

https://farm4.staticflickr.com/3859/15051668920_e10a3d511f_s.jpg (https://flic.kr/p/oW4JM7)Foam stringer (https://flic.kr/p/oW4JM7) by stephenspann27 (https://www.flickr.com/people/12361950@N02/), on Flickr


https://farm4.staticflickr.com/3852/15051591849_8e75295bae_s.jpg (https://flic.kr/p/oW4kSi)Foam stringer (https://flic.kr/p/oW4kSi) by stephenspann27 (https://www.flickr.com/people/12361950@N02/), on Flickr

[stephenspann27]

Picked up a skeeter bass boat with a 1985 150hp Blackmax XR2 on it. I will be swapping it onto my boat soon. I am ordering a tach just to satisfy my curiosity of what RPM I'm reaching with my TOP>

[milkdud]

Good keep us informed on your progress.

[Dave Strong]

Picked up a skeeter bass boat with a 1985 150hp Blackmax XR2 on it. I will be swapping it onto my boat soon. I am ordering a tach just to satisfy my curiosity of what RPM I'm reaching with my TOP>

Tachometer and water press gauges ar a must. Temp is also good.


Dave

[stephenspann27]

So.. this motor seized up with rust after sitting for only 3 weeks in dry storage. I unfroze it with WD40 and a break over bar. The starter seems to have hung and mostly burned up when I tried to start it. I put the boat back in storage, for a week, pulled it out again, and the motor was again seized up. Looks like I am for sure getting water in the powerhead.. and there has to be some corrosion in there now. I pulled the motor off the boat and I'm starting to tear it down for part out. Let me know what you guys want... if anything.

[Slimm]

So.. this motor seized up with rust after sitting for only 3 weeks in dry storage. I unfroze it with WD40 and a break over bar. The starter seems to have hung and mostly burned up when I tried to start it. I put the boat back in storage, for a week, pulled it out again, and the motor was again seized up. Looks like I am for sure getting water in the powerhead.. and there has to be some corrosion in there now. I pulled the motor off the boat and I'm starting to tear it down for part out. Let me know what you guys want... if anything.

Aw man I hate to hear that, bad news for sure. I will start looking around and trying to find something good around here if you want. I have a friend that had for sale a super nice low hour 2.4 200 with 138psi compression on all 6 cylinders. He took it off and replaced it with a new ficht engine for some stupid reason. I will see if he still has it, and ask around other places as well if you want.


Slimm

[Dave Strong]

Aw man I hate to hear that, bad news for sure. I will start looking around and trying to find something good around here if you want. I have a friend that had for sale a super nice low hour 2.4 200 with 138psi compression on all 6 cylinders. He took it off and replaced it with a new ficht engine for some stupid reason. I will see if he still has it, and ask around other places as well if you want.


Slimm

I would jump all over this offer!!!!!!

Dave

[stephenspann27]

Thanks for offering to look. I picked up a rotten skeeter boat with an '85 150hp Merc Blackmax on it. I will be picking the motor up from my parent's house Thanksgiving weekend.

[stephenspann27]

Starting to pull the motor apart.. this thing is trashed.

http://i192.photobucket.com/albums/z303/stephenspann27/2014-11-15121609_zpsec4198df.jpg (http://s192.photobucket.com/user/stephenspann27/media/2014-11-15121609_zpsec4198df.jpg.html)

http://i192.photobucket.com/albums/z303/stephenspann27/2014-11-15122307_zps68fe57ad.jpg (http://s192.photobucket.com/user/stephenspann27/media/2014-11-15122307_zps68fe57ad.jpg.html)

[Dave Strong]

No water got in there. :eek:;)

Dave :cheers:

[stephenspann27]

Wow.. I just took the exhaust plate off, this is for where the water got in. All kind of interesting finds. There is a bunch of mud near the top of the block stuck in the corner. I found some water pump blades on the outside of the plate, as well as some paper looking fiberish material.. might be plant matter. Ok this is what is blowing my mind. It looks like there is fiberglass in the motor. I've heard of fiberglass gas tanks causing this, but I am 99% sure my tank is plastic, and I also use several fuel filters. Does salt grow fiber looking strands? There is also what looks like yellow snot all in this thing. These salt deposits are wet, even though the motor hasn't run in months. Pics in the next post.

[stephenspann27]

http://i192.photobucket.com/albums/z303/stephenspann27/boat/2014-11-15154348_zps277a874a.jpg (http://s192.photobucket.com/user/stephenspann27/media/boat/2014-11-15154348_zps277a874a.jpg.html)

[stephenspann27]

http://i192.photobucket.com/albums/z303/stephenspann27/boat/2014-11-15154332_zps0020fd55.jpg (http://s192.photobucket.com/user/stephenspann27/media/boat/2014-11-15154332_zps0020fd55.jpg.html)

http://i192.photobucket.com/albums/z303/stephenspann27/boat/2014-11-15154316_zps228209b7.jpg (http://s192.photobucket.com/user/stephenspann27/media/boat/2014-11-15154316_zps228209b7.jpg.html)

http://i192.photobucket.com/albums/z303/stephenspann27/boat/2014-11-15154311_zps840a5d0d.jpg (http://s192.photobucket.com/user/stephenspann27/media/boat/2014-11-15154311_zps840a5d0d.jpg.html)

http://i192.photobucket.com/albums/z303/stephenspann27/boat/2014-11-15154302_zps13394892.jpg (http://s192.photobucket.com/user/stephenspann27/media/boat/2014-11-15154302_zps13394892.jpg.html)

[stephenspann27]

http://i192.photobucket.com/albums/z303/stephenspann27/boat/2014-11-15154256_zpsfdd4eb10.jpg (http://s192.photobucket.com/user/stephenspann27/media/boat/2014-11-15154256_zpsfdd4eb10.jpg.html)

http://i192.photobucket.com/albums/z303/stephenspann27/boat/2014-11-15154240_zpse3a3bdfd.jpg (http://s192.photobucket.com/user/stephenspann27/media/boat/2014-11-15154240_zpse3a3bdfd.jpg.html)

http://i192.photobucket.com/albums/z303/stephenspann27/boat/2014-11-15154225_zps97e47d36.jpg (http://s192.photobucket.com/user/stephenspann27/media/boat/2014-11-15154225_zps97e47d36.jpg.html)

http://i192.photobucket.com/albums/z303/stephenspann27/boat/2014-11-15154219_zpse5e85426.jpg (http://s192.photobucket.com/user/stephenspann27/media/boat/2014-11-15154219_zpse5e85426.jpg.html)

http://i192.photobucket.com/albums/z303/stephenspann27/boat/2014-11-15154210_zpsd76d36f7.jpg (http://s192.photobucket.com/user/stephenspann27/media/boat/2014-11-15154210_zpsd76d36f7.jpg.html)

[stephenspann27]

http://i192.photobucket.com/albums/z303/stephenspann27/boat/2014-11-15154204_zpsa657bc3f.jpg (http://s192.photobucket.com/user/stephenspann27/media/boat/2014-11-15154204_zpsa657bc3f.jpg.html)

http://i192.photobucket.com/albums/z303/stephenspann27/boat/2014-11-15154153_zps81810341.jpg (http://s192.photobucket.com/user/stephenspann27/media/boat/2014-11-15154153_zps81810341.jpg.html)

http://i192.photobucket.com/albums/z303/stephenspann27/boat/2014-11-15154143_zps3db7398b.jpg (http://s192.photobucket.com/user/stephenspann27/media/boat/2014-11-15154143_zps3db7398b.jpg.html)

http://i192.photobucket.com/albums/z303/stephenspann27/boat/2014-11-15154130_zps268eb47a.jpg (http://s192.photobucket.com/user/stephenspann27/media/boat/2014-11-15154130_zps268eb47a.jpg.html)

http://i192.photobucket.com/albums/z303/stephenspann27/boat/2014-11-15154108_zps55770d1a.jpg (http://s192.photobucket.com/user/stephenspann27/media/boat/2014-11-15154108_zps55770d1a.jpg.html)

[stephenspann27]

any ideas on the fiberglass looking stuff? Some kind of organic growth?

[stephenspann27]

Did some further investigating this morning.I found a blocked water jacket passage that has two water pump blades in it. The fiberglass.. spiderweb looking stuff.. I'm pretty sure is some kind of mold. If you roll it between your fingers it disappears and just leaves a sticky film on your fingers.

http://i192.photobucket.com/albums/z303/stephenspann27/boat/2014-11-16073108_zps3a163ebd.jpg (http://s192.photobucket.com/user/stephenspann27/media/boat/2014-11-16073108_zps3a163ebd.jpg.html)

http://i192.photobucket.com/albums/z303/stephenspann27/boat/2014-11-16073125_zps18df5f84.jpg (http://s192.photobucket.com/user/stephenspann27/media/boat/2014-11-16073125_zps18df5f84.jpg.html)

http://i192.photobucket.com/albums/z303/stephenspann27/boat/2014-11-16073327_zps093e6d5e.jpg (http://s192.photobucket.com/user/stephenspann27/media/boat/2014-11-16073327_zps093e6d5e.jpg.html)

[stephenspann27]

Do newer motors have much better corrosion protection?

[powerabout]

84 was the first year Mercs were built to go in sea water, was a huge jump from the 70's freshwater only things

[stephenspann27]

I always thought these I6's were cool. Now that I am taking it apart I see what a stupid over complicated design it is. I wish I hadn't put so much money into keeping this thing going. I should have scraped it a long time ago....
Back to more photos.. I found even more water pump blades! I also found a broken ring. That was probably the 90 psi cylinder. One of the rods is seized on the crank journal, several piston rings are seized with rust. What's funny is the cylinders that didn't have water sitting in them have been steam cleaned by the water vapor so they look spotless.

[stephenspann27]

http://i192.photobucket.com/albums/z303/stephenspann27/boat/2014-11-16154347_zps721cff0c.jpg (http://s192.photobucket.com/user/stephenspann27/media/boat/2014-11-16154347_zps721cff0c.jpg.html)

http://i192.photobucket.com/albums/z303/stephenspann27/boat/2014-11-16161156_zps64964115.jpg (http://s192.photobucket.com/user/stephenspann27/media/boat/2014-11-16161156_zps64964115.jpg.html)

http://i192.photobucket.com/albums/z303/stephenspann27/boat/2014-11-16161126_zps7b4b2254.jpg (http://s192.photobucket.com/user/stephenspann27/media/boat/2014-11-16161126_zps7b4b2254.jpg.html)

http://i192.photobucket.com/albums/z303/stephenspann27/boat/2014-11-16161106_zpsb42aa6bb.jpg (http://s192.photobucket.com/user/stephenspann27/media/boat/2014-11-16161106_zpsb42aa6bb.jpg.html)

http://i192.photobucket.com/albums/z303/stephenspann27/boat/2014-11-16161039_zps9f8dcc79.jpg (http://s192.photobucket.com/user/stephenspann27/media/boat/2014-11-16161039_zps9f8dcc79.jpg.html)

[stephenspann27]

http://i192.photobucket.com/albums/z303/stephenspann27/boat/2014-11-16161029_zps7ba1cc27.jpg (http://s192.photobucket.com/user/stephenspann27/media/boat/2014-11-16161029_zps7ba1cc27.jpg.html)

http://i192.photobucket.com/albums/z303/stephenspann27/boat/2014-11-16160005_zps90a1cb0c.jpg (http://s192.photobucket.com/user/stephenspann27/media/boat/2014-11-16160005_zps90a1cb0c.jpg.html)

http://i192.photobucket.com/albums/z303/stephenspann27/boat/2014-11-16162032_zpsae3b1499.jpg (http://s192.photobucket.com/user/stephenspann27/media/boat/2014-11-16162032_zpsae3b1499.jpg.html)

http://i192.photobucket.com/albums/z303/stephenspann27/boat/2014-11-16154337_zpsccd0a631.jpg (http://s192.photobucket.com/user/stephenspann27/media/boat/2014-11-16154337_zpsccd0a631.jpg.html)

[milkdud]

So.. this motor seized up with rust after sitting for only 3 weeks in dry storage.

I think its obvious the inner water jacket was bad letting water into your cyls. The engine looks like hell inside. I can see the brows are detonated partially off some of your pistons. Likely from the running it at low RPM for so long on a heavy boat with a 17 pitch prop.


I should have scraped it a long time ago....

Yes I think we mentioned that.


I picked up a rotten skeeter boat with an '85 150hp Merc Blackmax on it.

Now your thinking, now move away from that Inline 6 slowly before it sucks you back in. Put a bullet in it, its over.

[Slimm]

I think its obvious the inner water jacket was bad letting water into your cyls. The engine looks like hell inside. I can see the brows are detonated partially off some of your pistons. Likely from the running it at low RPM for so long on a heavy boat with a 17 pitch prop.



Yes I think we mentioned that.



Now your thinking, now move away from that Inline 6 slowly before it sucks you back in. Put a bullet in it, its over.



:iagree: As cool as the old inline 6 engines were, they are now more for the guys wanting to keep the old stuff running for nostalgia or having era specific engines than efficiency and power in my opinion. They did run great and sound awesome but they just can't compete with the newer technology and your wallet will thank you ten times over.

Slimm

[stephenspann27]

I'll have to take a closer look at the pistons. I didn't see any signs of damage to the "heads." I noticed there were several reeds that are not sealing, that was likely part of my idle problem. I'm so looking forward to the V6 where you don't have to completely disassemble the engine to replace the reeds. Yes.. I started out thinking I6's were cool.. but after taking thing one apart I hate them. I have already sold the lower unit.. and I have the disty, carbs, and prop on ebay. Should I just scrap the block/crank/rods? I don't see anyone wanting those..

[Slimm]

I definately wouldn't junk it as there are people out there who want them for restorations and other antiques reasons.

Slimm

[Capt.Insane-o]

I'll take the trim rams, carbs and reed blocks and distributor. I6's are cool, they sure run beautiful when done right.

309789

[Dave Strong]

I'll take the trim rams, carbs and reed blocks and distributor. I6's are cool, they sure run beautiful when done right.

309789

They have a cool unique sound as well.

Dave

[milkdud]

Yes as cap says. they are cool. Ive got a mini barn full of them. And they run great too, just leave the basket cases alone.


Should I just scrap the block/crank/rods? I don't see anyone wanting those..

as far as your crank and rods. there is a good chance the crank is pitted and possibly the rods too if it looks that bad. Nobody wants to buy a block with rust and corrosion oozing out of it.

disassemble the rods and look at the crank journals. If they are clean maybe it would sell. I see inline cranks sitting for awhile on ebay...

[milkdud]

what dave said...

[stephenspann27]

The crank might be costly to ship as well.
Capt. Some the reeds have rust on them... I'll take some pics. I'm not sure if I can break those phillips screws loose either.. who uses phillips head bolt on something like that? The carb and distributor are on ebay. I haven't posted the tilt/trim setup yet. Might be tricky to ship... The trim cylinders were dripping when I used it last, so they will need new seals. The trim motor is in good shape.


Dizzy:

http://www.ebay.com/itm/181588338230?ssPageName=STRK:MESELX:IT&_trksid=p3984.m1558.l2649

Carbs:
http://www.ebay.com/itm/181588326228?ssPageName=STRK:MESELX:IT&_trksid=p3984.m1558.l2649

[milkdud]

It takes a good phillips screwdriver with the proper head size do to it. The phillips needed usually is flat on the end. If you have the right phillips they grab like crazy and work. Using a #2 will just round things off.

[Dave Strong]

The phillips style that have the flat on the end are called Pozi Drive. I have some Snap On ones that you can put a box end wrench on the shaft and use your body weight to keep the tip in the screw while using the wrench to turn, works awesome. Use a heat gun to heat the half with the threads helps also.

Dave

[powerabout]

pozi are great
usually have a cross marked across the head, but the sides are not tapered hence they hold real well

[Dave Strong]

Common in Rochester Carbs, Holley base to body screws as well. Buggered a few screws many years ago till I got the correct drivers.

Dave

[stephenspann27]

I was thinking about buying one of those impact kits where you hit the "screw driver" with a hammer. My dad has one and I've broken a lot of stuff loose with it. Luckily I haven't buggered the phillips head yet.

[Dave Strong]

I would try it my way first, less chance of damage. JMO
Not fond of taking a hammer to anything on a crank unless no other option.

Dave

[stephenspann27]

hrmmm http://i.imgur.com/iZMnRo8.png

[stephenspann27]

I have a dewalt ribbed bit somewhere that does really well. If I put that in a socket adapter.. I could probably get them out.

http://i.imgur.com/1ZUJ9xZ.png

[powerabout]

phillips are crap, should never have been invented

[Dave Strong]

phillips are crap, should never have been invented

Thats why the Canucks invented the Robertson bit. lol

Dave

[Mark75H]

There is also the tapered Reed and Prince that looks like a Phillips but isn't

[milkdud]

A #3 or #4 is what you need they look like this....

[stephenspann27]

The block and rotating assembly are actually cleaning up really well. I guess because the rust/corrosion wasn't there long. I haven't seen any pitting. I'll pull the crank assembly apart soon. #1 piston looks pretty bad, lot's of detonation pitting. I don't see any other detonation on any others. One of the piston ring landings is also broken on #1.

http://i192.photobucket.com/albums/z303/stephenspann27/boat/2014-11-18173457_zps8986ba9f.jpg (http://s192.photobucket.com/user/stephenspann27/media/boat/2014-11-18173457_zps8986ba9f.jpg.html)

http://i192.photobucket.com/albums/z303/stephenspann27/boat/2014-11-18173437_zpsb3069160.jpg (http://s192.photobucket.com/user/stephenspann27/media/boat/2014-11-18173437_zpsb3069160.jpg.html)


http://i192.photobucket.com/albums/z303/stephenspann27/boat/2014-11-18173430_zps5828e72d.jpg (http://s192.photobucket.com/user/stephenspann27/media/boat/2014-11-18173430_zps5828e72d.jpg.html)

http://i192.photobucket.com/albums/z303/stephenspann27/boat/2014-11-18173425_zps3dabd907.jpg (http://s192.photobucket.com/user/stephenspann27/media/boat/2014-11-18173425_zps3dabd907.jpg.html)

http://i192.photobucket.com/albums/z303/stephenspann27/boat/2014-11-18172103_zps3941095e.jpg (http://s192.photobucket.com/user/stephenspann27/media/boat/2014-11-18172103_zps3941095e.jpg.html)

[stephenspann27]

That's a piece of the piston laying on top of #1, not a piece of ring.

[stephenspann27]

Wow, this video hits home. "These exhaust baffle gasket fail often, luckily this is a fresh water motor."


https://www.youtube.com/watch?v=tSXXF05WFRg

[Mark75H]

Even in fresh water. Along with the distributor wires, its the most fragile part of the motor

[powerabout]

We used to change them out after 5 years along with the bottom seal.
The 2 destroyers of inlines

[stephenspann27]

Change the spark plug wires? I didn't know they were a problem. Do people remove the exhaust plate often to check for leaks?

[Mark75H]

Not the spark plug wires, the power and trigger wires between the distributor and switch box.

The usual sequence is see water in the motor and confirm its not something easier to repair ... then disassemble and check that inner plate. Its not something that is checked often ... but its a known killer of many of these motors. Clean, wet or rusty spark plugs are bad news

[powerabout]

Quick simple test is to cut the puddle drain hose (then join back as it difficult to remove at either end with the engine cowls on or fit clear fuel resistant hose) that goes from under the bottom bearing to oil the top, if that has water in it you are half dead. You can run the engine with it removed at idle for a short while and it will pump out of the bottom.
In a clear hose you will see it milky, make sure the hose has the same ID if you replace it.

[stephenspann27]

Ahh good tip. I'm excited about moving onto the V6, I'm sure they have their own set of weaknesses. But I'm really looking forward to having removable heads, and reeds in the intake. Also.. no distributor.

[Dave Strong]

Ahh good tip. I'm excited about moving onto the V6, I'm sure they have their own set of weaknesses. But I'm really looking forward to having removable heads, and reeds in the intake. Also.. no distributor.

First things you need to get are a factory Merc shop manual and a DVA meter.

Dave

[stephenspann27]

Looks like the lower main seal was another water entry point. The seal housing was full of water and the bearing has seen better days. I got the crank torn apart. Some of the rods looks to be in really good shape, the other have some rust stain. The reed blocks are in good shape. It looks like the wrist pins got pretty hot.


http://i192.photobucket.com/albums/z303/stephenspann27/boat/2014-11-21174540_zpsd9c39aeb.jpg (http://s192.photobucket.com/user/stephenspann27/media/boat/2014-11-21174540_zpsd9c39aeb.jpg.html)


http://i192.photobucket.com/albums/z303/stephenspann27/boat/2014-11-21175951_zps4f233e1b.jpg (http://s192.photobucket.com/user/stephenspann27/media/boat/2014-11-21175951_zps4f233e1b.jpg.html)


http://i192.photobucket.com/albums/z303/stephenspann27/boat/2014-11-21175945_zpsb4e86ae7.jpg (http://s192.photobucket.com/user/stephenspann27/media/boat/2014-11-21175945_zpsb4e86ae7.jpg.html)


http://i192.photobucket.com/albums/z303/stephenspann27/boat/2014-11-21175935_zps7f0c21de.jpg (http://s192.photobucket.com/user/stephenspann27/media/boat/2014-11-21175935_zps7f0c21de.jpg.html)


http://i192.photobucket.com/albums/z303/stephenspann27/boat/2014-11-21171911_zps638249ff.jpg (http://s192.photobucket.com/user/stephenspann27/media/boat/2014-11-21171911_zps638249ff.jpg.html)

http://i192.photobucket.com/albums/z303/stephenspann27/boat/2014-11-21172539_zpsa442a1cc.jpg (http://s192.photobucket.com/user/stephenspann27/media/boat/2014-11-21172539_zpsa442a1cc.jpg.html)

[powerabout]

seen those pictures a thousand times

[stephenspann27]

what's that? I6' destroyed by water?

[stephenspann27]

I got the Black Max 150 hooked up. https://www.dropbox.com/s/5ze4jkc9jrbfw5f/2015-03-21%2018.00.56.mov?dl=0 <--- Video

[Slimm]

Awesome, wait until you get on the water and hammer that throttle down. The difference should be huge. I bet you'll be grinning from ear to ear!

Slimm

[stephenspann27]

I still have a bunch of '78 140 parts I need to unload.. including the tilt/trim - pump etc.