1989 Mariner 175Ski

[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:


===

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:


===

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 oneI'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.

[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

[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?



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, 2.4L88, or 90? 2.4L

[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?



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.