Seadoo battery

[Matt 76]

Need some help. I have a 1996 seadoo GTX 787 with 64 hours on it. All fuel lines were changed 3 years ago carbs rebuilt with OEM kits. Here’s the problem ski will start on first hit then once turned off will not restart . Turns over but check plugs and they have gas on them. From what I gather just because battery turns motor over doesn’t mean it’s strong enough to have a strong spark. So with that being said I put my battery charger on it not on boost start just 2-10 amps it fires right up. With that being said is it the battery? Thanks in advance ..

 

[artr]

Sounds like the battery. I think you should have the battery load tested. You could put a voltmeter on the battery and observe the reading when you crank the engine to start it. A good battery will not drop much while cranking. I believe I read where the CDI module will not fire if the voltage drops below 10V. It is not clear from your description if you turn it off immediately or ride it for a while before restarting, but if you ride for a while you might want to check that the battery is being charged while the ski is running. You can do that by monitoring the voltage on the battery and revving the engine to 4000-5000 rpm and see if the voltage rises to around 14V.

 

[Matt 76]

Thanks for reply. This happens right after I start it and shut off on trailer. I’ll check the voltage later today

 

[mikidymac]

Never, ever, ever use any charger or booster to start your seadoo as you will likely fry the MPEM computer.

Take the battery to any auto parts chain store and they can load test it for you.

 

[POPPS]

A weak battery will produce a weak spark.

 

[edchris]

As Miki above said...
If your battery is low, remove it, or at least undo the cables before hooking up a charger. This is written in bold font in the service manual.
You do not want to buy a new MPEM.