Stuck Motor on 2001 Challenger 2000 with 240 EFI M2

[Greenovni]

Hello Everyone. This is my first post as well as my first Seadoo Boat.

I recently bought a 2001 Challenger 2000 with the 240 EFI M2 engine and according to the previous owner, the boat has been sitting under a tree for the past year. The previous owner said that the only thing wrong was the starter so once I got home I removed the rusty and seized looking started and bought a new one and it didn't turn the flywheel.

My next step was to unbolt new starter again so I can separate from flywheel and tried to turn the flywheel by hand and had absolutely no play.

Then I removed the sparkplugs to release compression and to my horror there was rust on 2 spark plugs. 1 was really rusty and the 2nd one not so much.

I called the old owner and he said that the last time he ran the boat it was running fine and then parked it under a tree at his house for the past year.

A local boat mechanic told me to spray the cylinders with penetrating oil so I used P'Blaster & a few squirts of mystery oil but the flywheel still wont budge.

Today I received a scope / camera to look in the cylinders and they all look rust free except 2 that show what it seems to be surface rust only on some sections while the rest of the cylinder looks great.

Does anyone know what would be the easiest way for me to free this engine since I've spent my life's savings on this boat?

I can take pictures of the cylinders if I have no other choice but to open the heads

 

[Sandman251]

Hi. You're on the right track. Same thing happened to me on a 787 Rotax. You can do a little more research on what the best solvent/oil to use is. I used Marvel Mystery too. Spray a liberal amount of penetrating oil into the cylinders and let it do it's thing. I let it sit for a week. Then take a long lever/breaker bar (4 feet if you can find one) and go to work. Lots of guys advocate using an impact gun. I didn't, but in situations like this, sometimes there is something to be said for a little smack if the constant pressure won't work. I wouldn't worry just yet. If you can't get it, Take it to an outboard shop. Im sure they can break it loose for you cheap. And if not, They should be able to let you know what's going on. Good luck.

 

[Greenovni]

Were you able to get it going?

Mine is still stuck

 

[Coastiejoe]

If you truly WANT to believe the seller, which is questionable at best IMO, then you can try the following.
Fil the cylinders with either transmission fluid or diesel fluid. Tranny fluid works pretty well.

In most cases, when it only needs a Starter, Battery, or MPEM it is almost always considerably more serious and more expensive,,

It is almost always a seized engine.