Stuck 1987 200HP

[BoatTrain]

I ran this engine 3 weeks ago with no problem. I went to crank it up today and it is just plain stuck. I pulled the spark plugs and saw nothing. I put a socket wrench on the crank shaft bolt and it does not turn. It moves one tooth at a time when I hit the starter. I filled up the cylinders with penetrating oil, figured I would see what happens tomorrow, any suggestions on what’s happening?

[jonp]

That Sucks... Never heard of something happening all of a sudden after running fine weeks earlier. I have been playing with outboards for 35+ years... I would trim your engine up as much as you can and let that stuff penetrate in thru the spark plugs and let it sit for a while. Fogging oil in the carbs would not hurt either to be sure its getting lubed from both ends. Be real careful as you try turning, if you sense any grinding just stop... Is it possible water got in this engine?

[99yam40]

Drop the lower unit and make sure that it is not the thing that is locked up. Your motor could be free, but the shaft to lower unit binding it up.

[BoatTrain]

Thanks for the suggestions, the lower unit was dropped and the engine is still "stuck", will only move one tooth at a time when I hit the key, I do have the oil soaking, so.... I hope that it frees up. Any additional thoughts?

[99yam40]

You need to open it up to see what is going on, if there was water involved then crank and bearings could be shot. Oil will not make rust go away

[jb123]

at this point i would pull the heads

[BoatTrain]

Ok...a little more information....and I hope some advice from you all. My neighbor and myself figured that we did not have much to loose at this point so we used and electric impact wrench on the crankshaft 30mm nut and the starter at the same time, we were able to get it un-stuck. We used the breaker bar and ran it around a bit then we put the spark plugs back in and was able to get it running, slow cranking at first, a little starting fluid and off it went, of course there was much smoke because of all the oil. After it ran for about 15-20 minutes at a high idle 1500-1800 rpm we did a compression check. Facing the engine from inside the boat the right side was top to bottom 125-125-125, the left side was top to bottom was 025-125-115. Should we pull the left side head next? Thoughts? What do we look for? If we pull the head do you know the head bolt torque pattern? Do you use a sealant on the gasket? Thanks for you help.

[99yam40]

I would recommend getting a manual for your motor, it will give you all the info you need and the steps it takes to do everything.

I am sure You are going to find more than a gasket problem with your motor and will have to pull the power head and disassemble to repair. May find rusted parts if water was involved inside motor cylinders and crankcase (bearings and crank)