Help Please

[Ray Meattey]

Yesterday I took out my newly purchased 1998 Speedster 1800. I ran it at idle for approx 15 minutes since this was the first time I ever had a jet boat. Both engines started fine and ran at idle. Then when I tried to start accelerating the drivers side motor would stall. I sat a few more minutes waiting for it to idle then we were ok for approx 15 min of riding then I could tell we were not running properly so i stopped and put in nuetral engine had stallled so I clamped the intake and limped to the dock. Now I can't get engine to restart. Any info will help and thanks!!!!!!!

 

[Dr Honda]

Well.......


Sounds like it had a fuel problem. When they sit over winter, sometimes the carbs need some love to get them to run properly in the summer. Especially if they weren't winterized properly. But, for giggles... check the compression. A fresh engine should be 150 psi, and 135 psi will be the bottom of usable pressure.

 

[Ray Meattey]

Thanks I have tried to remove plugs and blow out any water. I also put a little mixed gas in and tried to blow that out then I put a mixture back in and installed the plugs turns over still not starting

 

[Dr Honda]

Check for a spark. Put a plug in a wire, and ground it. the gap on a seadoo is small (0.022") so make sure that is right. Also... spark plugs can decay internally. try a new set of plugs.

 

[RFoster130]

Anytime I notice there is an issue with it not running properly I start with a new set of plugs. Start there and see how it does. Also, if its an 18 ft boat, its a challenger or a sportster. The speedster is 16.5 feet. The sportster 18' had twin 85hp motors and the challenger 18' had twin 110 hp motors.

 

[Ray Meattey]

Rfoster you are correct it is a sportster with twin 85's. No spark with a new set of plugs

 

[Dr Honda]

OK... open your electrical box, and find the wire that goes from the MPEM and intersects the wire between the coil, and the stator. (should be Black/red)

Disconnect it, and see if you get a spark.

If you do... then something is up with your MPEM. If you don't... the stator or coil are bad. (the 720 coil has the CDI built into it)

Don't try to run the engine with that wire disconnected. That is the kill, and rev-limiter from the MPEM.

 

[Ray Meattey]

Igot it running really really ragged, I think old oil and gas mixture!!!!!!!!!!! Is that possible?

 

[Ray Meattey]

my neighbor seems to think its running on 1 cylinder could this be something in the ignition system. Seems like i'm getting a weak spark on the bad cylinder.