Stuck Mercruiser 205 ~ 4.3L V6

[sethbarker]

I recently purchased a 1987 Sundancer 270 in Honolulu, Hi. I found that the Port engine has seized. Oil looks great, however the boat has been sitting int's slip for the past 3-4 years without being run. grrrr! I have tried to no end to turn the crankshaft over manually, but no luck. I have removed the plugs and squirted 3 cans of heavy duty penetrating lube into the cylinders, but still not a budge. Any tips or tricks out there before I resign to the teardown?

 

[2000SEARAY280SS]

I worked on a Master Craft Chrysler that had been sitting. We tried everything including hitting the tops of the pistons with a hammer and a two by four. Turned out the starter was rusted to the flywheel. We removed it and it turned over like a champ.

 

[sethbarker]

Thanks.

 

[wileecoyote]

I know a guy who used to buy old tractors with siezed motors that had sat in fields for years. He would remove the head and fill the cylinder with oil and hit the top of the piston with a block of wood. Most often the rings were rusted to the bore. I think if you are going to that much trouble it may be worth it to remove the engine and go through it. I'm not sure I would trust a siezed motor on the water without going through it. That is if it's the motor thats locked. If you remove all the accessory belts and starter and it still doesn't budge, pretty good sign something internal.