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Seadoo GTS bent spark plug

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Vishismonkey

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Seadoo GTS with the 657x was running rough after a winter of improper storage (bought used off of some guy). Did not put new gas in (my mistake) and it would not accelerate at all. Would start consistently every time but would not go faster than a bit faster than idle.

finally drained the gas, added some 2 stroke Engine treatment along with some fresh premium. Did not fill tank entirely as my plan was to run the gas out in an effort to drain the system of any old remaining gas (unaware of potential risks of this method). Ended up running out of gas on the lake, although the ski seemed to clear up a bit and it was accelerating *better* but not necessarily perfect. It would sometimes hesitate out of the water but would eventually get to speed. When I took turns it seemed like it really bogged down a bit. I have never used this old of a jet ski before but I feel like it should be faster.

After I ran out of gas, I swam it back to shore (wasn’t far) and refilled with premium. Then it wouldn’t start. I thought it may have water in engine from me towing it into shore but I turned the engine over with the spark plugs off test and no water shot out. Lastly, I noticed that one of the spark plug ends was bent. (See pictures). I am uncertain as to when this happened - it could have happened right away and been the cause for my lack of acceleration, or it could have happened after I ran out of gas and tried to start it running lean.

really at a loss for direction at this point - is there anything I could check easily before I just drop it off at the shop? I do not have a good lift, I beach my ski and tie it off. To get on the trailer it’s got to be towed across the lake. Can I put a new plug in and give it a shot or will I risk further damaging the internals? Is vapour lock a potential culprit here?

there are pics of both plugs - one is clean and not bent and the other is dark and black and bent. I replaced these a week ago and they have no more than 1 hour of run time on them.
 

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There is nothing that can hit a sparkplug on these as the piston doesn't get close to it. Not sure how the plug electrode got bent.

I would check compression then install new plugs.

What "2-stroke fuel treatment" did you use? There is nothing in a bottle that will help these skis.
 
There is nothing that can hit a sparkplug on these as the piston doesn't get close to it. Not sure how the plug electrode got bent.

I would check compression then install new plugs.

What "2-stroke fuel treatment" did you use? There is nothing in a bottle that will help these skis.
Ok, that’s good news. I used STP small engine treatment thing. Couldn’t have been more than 100ml. Said it would help remove water, clear up fuel lines, etc. Maybe I shouldn’t have. I will replace bad plug and see if she starts.
 
I'd suspect that plug contacted something in the cylinder to smash that tip like it did. Look through the spark plug hole and check out what you can. Pull the head and have a look. The carbs need to come off for a rebuild and your entire fuel system needs work. Fuel tank needs to be drained and wiped clean. If you run an engine that is not getting proper fuel the end result will be very bad. Check the compression always, first thing. Good Luck
 
Having basically same thing happening to a 787 RFI in a GTX 2000. Run Premium gas but it does contain ethanol. The best non ethanol I can get my hands on here is 89.
Wonder if a good compression plus gas loaded with too much ethanol can heat the electrodes and simultaneously some shock wave bend them. I know that theory doesnt make a lot of sense but I am at loss here...
 
If you're still there trying to find out...I had the same symptoms but now just figured out what it is. I switched up the 2 coolant hoses at the back of the head. The MAG head overheats, plug too, shuts the gap since the electrode is about to melt.
Check the hoses dude !
 
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