Mayday 120 hp sport jet engine jammed

[biddissp]

Hello all,
I have been struggling with an issue with my 120 hp sport jet engine for some time now and have frankly run out of ideas of what to try.
The boat started in the spring time and was left in the water for a month or so. When I went back to try to start it.... nothing.

So I tried the normal things eventually finding that the engine was jammed by something. I can rotate it 180 degrees and it hits something hard in both directions. I have removed most components the jet pump and isolated the issue to the engine itself. When you turn it each of the cylinder strokes. Does anyone have any ideas on what this could be??

Thanks
Paul

[boats.net]

Pull the cylinder head and look at pistons for damage.

[biddissp]

Thanks for the tip I will try that and get back to you on what I find.

[dave86]

check your flywheel see if the magnets let lose and jammed in stator. mine got hard to start every now and then , then scattered magnet shards