2002 Seadoo GTX DI - Bent Spark Plug - Runs Rough - Need Help

kevinstan

Petty Officer 2nd Class
Joined
Aug 19, 2012
Messages
169
New to me 2002 Seadoo GTX DI. Guy I bought it from told me he used Sta-Bil before winter, so I should run it easy to run the fuel stabilizer out. First time to the lake it started and appeared to be fine, until I started running it. Ran really rough and would bog down a lot. Got back to shore and took out the spark plugs and one was solid black, and the curved piece of the plug was bent down touching the other piece - no gap at all. Took the jet ski home and drained all the fuel and put a new gallon of gas in with some seafoam in hopes of cleaning it out good. It then sounded good when running it at home, but I took it back to the lake today and the same thing happened. Here is my next steps:

1. Getting a bore scope tomorrow to look down through the spark plug hole to see if it is excessive carbon build up, or a large broken off piece of carbon that has come loose.

2. If it is excessive carbon I plan on using the spray seafoam on the inside to try and dissolve it.

3. Doing a compression test tomorrow as well to see if both are within 10psi of each other.

Is there anything else anyone can suggest? I am not really sure of what to do next. I have read stuff saying it could be piston rings or a rod?

Anyone else have this problem before? And can anyone tell me if I am even starting at the right place to diagnose? The spark plug being bent the way it was concerns me that it is a bigger problem, but I have my fingers crossed that it is something simple.

Thank you very much to everyone in advance for any help you can offer.
 
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