Help please! ‘98 Seadoo Speedster- 1 engine not running

[Smit4225]

Hi! Looking for advice, one engine on the ‘98 speedster crapped out last weekend, it will spark but won’t run. We replaced the coil and plugs…didn’t take. I was thinking stator magneto, but have very little experience with jet boats? Any suggestions are appreciated.

 

[tdonoughue]

Let's go back a step. You say it has spark.... that would indicate that the electrical is fine. So I would be very surprised after that if it is the plugs, coil or the magneto.

So then, fuel: If one engine is running and the other is not and they are drawing from the same fuel, it is not the fuel itself. In the fuel category, though you can also have carbs/injectors (not sure which ones you have). If it is a carb: was it running rough before it cut out? Or running rough before you turned it off and it wouldn't start? If injector: you can swap an injector with the other engine to see if it helps. Also check the electrical connectors going to the injectors. Lots to look at in the fuel system... fuel pump too.

Final thing to make it run is compression. For that, you start diagnosis by doing a compression test on the engine. Got a compression tester? You can get cheap ones cheap on Amazon. May be able to borrow one from AutoZone or similar. Lack of compression can indicate that the head gasket is blown or rings are bad on the pistons or you have a valve issue.