2002 merc 25 motor seized after being laid on side for years

[jastampke]

I am new to this forum and new to outboards but am fairly familiar with engines. i bought this motor crazy cheap the other day hoping i will be able to fix it. the fella selling it says it was taken off of the boat it was on after 10hrs of use because a larger engine was desired and laid on its side for like 10 years. So now it is locked up. I havent tried pouring any solutions in the cylinder yet. what do you guys think? if this guys story is straight and i do get the motor unlocked will the cylinders and piston be good to go or will i need to replace them?

 

[carholme]

Re: 2002 merc 25 motor seized after being laid on side for years

What is the s/n of the engine?

Why not just get some fuel/oil mix into the cylinders, allowing it to soak for a day and see if you can turn the flywheel with a socket and breaker bar. Might also be wise to remove the lower unit and ensure that it is free and not corroded into the crankshaft splines. There is probably going to be marks in the cylinder walls where the rings have sat for such a long time but if there was no corrosion, you may get away with it.

Gerry

Gerry

 

[jastampke]

Re: 2002 merc 25 motor seized after being laid on side for years

What is the s/n of the engine?

Why not just get some fuel/oil mix into the cylinders, allowing it to soak for a day and see if you can turn the flywheel with a socket and breaker bar. Might also be wise to remove the lower unit and ensure that it is free and not corroded into the crankshaft splines. There is probably going to be marks in the cylinder walls where the rings have sat for such a long time but if there was no corrosion, you may get away with it.

Gerry

Gerry

the s/n is 0T544057

 

[carholme]

Re: 2002 merc 25 motor seized after being laid on side for years

That s/n comes up as:

MERCURY - ( 25 H.P. (2002 ))
Serial No: 0T544057 Model No: 1025312ZN

Parts and service Bulletin List for s/n 0T544057:

Search Results - Crowley Marine

The service manual you require is P/N: 90-826883R03. If you do not have one, see my PM to you in Notifications at the top of the page.

Gerry

 

[jastampke]

Re: 2002 merc 25 motor seized after being laid on side for years

It looked pretty crusty when i pulled the plugs so i went ahead a squirted some ATF in the cylinder. gunna let her soak a while now. when i laid the motor down oil started seeping from the prop. Is this normal?

 

[wired247]

Re: 2002 merc 25 motor seized after being laid on side for years

Is it transmission oil seeping from the prop? Might not look like it if it is all mixed up with exhaust soot. Remember a 2 stroke has a straight shot from the exhaust port to the prop hub.

 

[jastampke]

Re: 2002 merc 25 motor seized after being laid on side for years

no its definetly not ATF. All that is still sitting on top of the piston. this is a thin oil, quite a bit of it too.

 

[Silvertip]

Re: 2002 merc 25 motor seized after being laid on side for years

What is the s/n of the engine?

Why not just get some fuel/oil mix into the cylinders, allowing it to soak for a day and see if you can turn the flywheel with a socket and breaker bar. Might also be wise to remove the lower unit and ensure that it is free and not corroded into the crankshaft splines. There is probably going to be marks in the cylinder walls where the rings have sat for such a long time but if there was no corrosion, you may get away with it.

Gerry

Gerry

Using a breaker bar is a very bad idea. You risk breaking rings and ring lands on pistons with too much effort. Get a penetrating oil in the cylinders, lay the engine on it's back (plugs facing upward). Now walk away for at least several days. Now very gently (NOTE THE WORD GENTLY) , using a wrench or breaker bar attempt to rock the crankshaft back and forth. If it moves even a little bit, do not force it through the restriction. Add more penetrating oil, rock the crank a bit and walk away again. If you get the idea this is an exercise of patience, you are right. Keep repeating this process until the crank can be turned freely. If the crank cannot be turned at all, at more penetrating oil and wait. Repeat, repeat, repeat as often as necessary. Once you get a bit of movement, you should be home free. Whether or not the cylinders are rusted or scored, rings are stuck in the lands, etc., you will only tell when you attempt to fire the engine. Go very heavy on the two-stroke during the initial running to get things well lubricated. I'm gong to guess that the crank and bearings are rust covered and the engine will not live long if you do get it running.

 

[jastampke]

Re: 2002 merc 25 motor seized after being laid on side for years

I'm thinking this motor has had oil setting in it all these years. That's what is coming out of the exhaust. That would be a good thing I suppose

 

[jastampke]

Re: 2002 merc 25 motor seized after being laid on side for years

ok, so when i get this motor freed up i want to get her running. this motor is a remote steering motor. I plan on buying the tiller conversion kit but dont want to do that until i know she running good. Any ideas on how i can run this motor without all the controls plugged up?

 

[orbanp]

Re: 2002 merc 25 motor seized after being laid on side for years

Is that a Mercury engine, does anyone know? When did Mercury go over for the two-stroke Tohatsu motors?
If it is a Mercury built engine, it would be shown on the ID plate that it was built in the USA.

If it is a Mercury engine, it is a pure aluminum block engine, Mercosil, no cast in liner, no rusting in the cylinder.
You would also see "Mercosil" cast into the block at the top left side, towards the head.
I am not sure if and how an aluminum block would corrode.

Any chance that the lower unit is stuck?
In any event, you would probably want to check/change the impeller, so you might as well drop the gear-case and see which part of the motor is stuck.

Good luck, Peter

 

[jastampke]

Re: 2002 merc 25 motor seized after being laid on side for years

Is that a Mercury engine, does anyone know? When did Mercury go over for the two-stroke Tohatsu motors?
If it is a Mercury built engine, it would be shown on the ID plate that it was built in the USA.

If it is a Mercury engine, it is a pure aluminum block engine, Mercosil, no cast in liner, no rusting in the cylinder.
You would also see "Mercosil" cast into the block at the top left side, towards the head.
I am not sure if and how an aluminum block would corrode.

Any chance that the lower unit is stuck?
In any event, you would probably want to check/change the impeller, so you might as well drop the gear-case and see which part of the motor is stuck.

Good luck, Peter

yes its a mercosil motor. So if the lower unit is stuck it wouldnt matter as long as its in nuetral correct?

 

[orbanp]

Re: 2002 merc 25 motor seized after being laid on side for years

yes its a mercosil motor. So if the lower unit is stuck it wouldnt matter as long as its in nuetral correct?

The lower unit (the driveshaft) could be stuck, even if the gear-case is in neutral. This would mean some damage in the gear-case.
If the lower unit is stuck, I would expect to see tiny movement back and fore at the crankshaft.
If the crankshaft is frozen solid, it could be one of the main bearings, or the pistons, depending on the position of the pistons.
In either case, if the soaking does not help, you would start by taking off the lower end.

Peter

 

[jastampke]

Re: 2002 merc 25 motor seized after being laid on side for years

ok. should i take the exhaust cover off to take a look, maybe spray some pen oil in there, see if there is any damage?

 

[orbanp]

Re: 2002 merc 25 motor seized after being laid on side for years

As mentioned, I would start by taking off the lower unit.
If it turns out that the lower unit is the cause of this, then you have not opened up the engine unnecessarily.
If the lower unit is fine, then you can start opening up the engine.
It is also worthwhile to change the water pump, so you have not lost anything by taking off the gear-case.
But it is ultimately your choice.

Peter

 

[jastampke]

Re: 2002 merc 25 motor seized after being laid on side for years

I didn't listen and pulled the exhaust cover off. One piston is brownish in color and the other is nice and clean looking. Looks like it got hot. There is signs of the plastic on the coil melted so I think it got hot. What do u guys think

 

[wired247]

Re: 2002 merc 25 motor seized after being laid on side for years

I think you need to drop the lower and see if the upper is locked up or the lower is locked up.

 

[jastampke]

Re: 2002 merc 25 motor seized after being laid on side for years

is the gear case the same thing as the lower unit

 

[carholme]

Re: 2002 merc 25 motor seized after being laid on side for years

Yes

Gerry

 

[Chinewalker]

Re: 2002 merc 25 motor seized after being laid on side for years

If you determine it is the powerhead, I'd go ahead and tear it down. Too many things can be causing the stuck-ness to chance it otherwise. As new as it is (by my standards) it's worth putting some time and money into it to make it right.