1995 200hp yamaha pro-v frozen flywheel

[Crockett]

Good morning all. I ran this engine 2 weeks ago with no issue. I tried to run it in my driveway in preparation for a fishing trip. Starter tries to engage the flywheel but cant turn the flywheel. I cant turn the flywheel with a large crescent wrench either. There is a very small amount of play in the fly wheel but it wont turn. Prop turns freely by hand. Any DIY advice will be greatly appreciated.

[rodbolt17]

remove the lower unit and try it again.
if it turns the lower is locked up, if it wont its the powerhead.

[Crockett]

Metal filings and milky oil in lower unit.

I drained the lower unit oil and discovered metal shavings and milky looking oil. Is this necessarily worst case scenario? I suppose i will drop,the lower unit and look at it. Not sure what ill be looking for. Im not a mechanic..... But if something obvious i may be able to notice it. Thanks for the response and help.

[99yam40]

If when you drop lower unit off of the motor and then the motor turns over, it mean the lower unit is locked up.
If it is still locked up with out lower on the the power head is locked up.
I do not see how this is so hard to under stand that this is what you are looking for

[TownsendsFJR1300]

Better the lower end locked up than the powerhead, much cheaper to fix...

Your checking to see if the lower unit is PREVENTING THE ENGINE FROM TURNING over.

You can also pull the spark plugs and inspect. If ones rusty/ different looking from the others, its NOT good for that cylinder.. (likely, their fine)

Metal and watery oil coming out of the lower end is NOT good. A seal(s) failed as well as something else mechanical...

[Crockett]

Fly wheel is free, but still suspect?

Thank you all for the information. I took out the spark plugs and all were dirty but one had a tiny bit of rust on it. I put marvel mystery oil in all cylinders. I dropped the lower unit and the flywheel still didnt turn. I put it all back together and tried to turn the nut on top. And it didnt move... I gave it about 8 hrs. It slowly gave and i worked it for a few complete revolutions. I put plugs back in and tried to start it. it coughed and smoked... Then started and sounds fine and starts perfectly in the driveway. I suspect i need to take it in to have someone that knows more than i to see why it got frozen after just sitting for a week after running fine. And im nervous now about the condition of the interior. Im dying to go run it.... But i suspect that would not be wise?

[Crockett]

Thanks for the insight scott. I really appreciate the direction.

[TownsendsFJR1300]

Thanks for the insight scott. I really appreciate the direction.

No problem but it sounds like water got into a cylinder and rusted it up/locking the engine up (per your rusty spark plug) . If its running good, your lucky it didn't SEEM to cause any major damage. Until you find the problem (see below) I would make sure the cylinders are clear of any water (pull plugs and re-lube) so it doesn't rust up again..

Possibly a blown head gasket, not sure if that engine is prone to exhaust water leaks into the cylinder. Someone will chime in about that..

The head isn't hard to remove (short of corrosion) but confirm if the exhaust has corrosion issues first..

[TownsendsFJR1300]

I wouldn't run it with a definite water leak into that cylinder. It won't fix itself obviously and can only get worse..

They may want to pull the head anyway to check the cylinder, maybe not if they have a good scope..


The lower unit definitly needs attention too. The more you run that, the more damage you cause..

[Crockett]

Frozen flywheel

Agreed! Thank you. Ill post final diagnosis and fix when it is done. It may be a while. Thanks again.

[TownsendsFJR1300]

Good luck, hopefully its something simple at both the top and bottom ends..

[Crockett]

Water in cylinders

I finally had a mechanic look at my motor.. He put a scope in and we could see moisture in several of the cylinders and rust in them as well. He will take them apart and inspect and replace the head gaskets.

[Livinlinelife]

Hope that fixes it for you. Just don't forget about the water in your lower unit, that needs some attention as well. Best of luck,

[TownsendsFJR1300]

I finally had a mechanic look at my motor.. He put a scope in and we could see moisture in several of the cylinders and rust in them as well. He will take them apart and inspect and replace the head gaskets.

Was moisture in BOTH SIDES of the engine(each side of the "V")? ie, both heads??

[Crockett]

Head gasket and lower unit

Thanks guys, yes there was moisture in both sides. Prominent in one side and barely detectable in the other side. Ill be sure to have lower unit serviced as well.