Seadoo won't go past 20mph

[Patrick Nelson]

My jetski ran fine for a few hours yesterday, then suddenly lost power. Would not go past 20 mph. It revs up normally but just doesn't seem to have much power. There is oil splatter around one of the cylinders. Any idea what is going on or what to start looking at? I don't know very much about engines. I attached a picture and can add more if needed. Thanks in advance for your help.

 

[Beachbummer]

Maybe your rave valves need a good cleaning and/or servicing? Is that a hole on your weld spot in the Tuned pipe? If the Tuned pipe is leaking severely that can also affect performance.

My seadoo has a 717 motor, so no raves on mine, but the Tuned pipe is very similar to mine. The pipes can leak at the weld.

Good luck.

 

[Patrick Nelson]

Thanks for the input, I will check tonight when I get home. No there is no hole, just a bad picture at night.

 

[Patrick Nelson]

Took the covers off the rave valve and one of them has a lot of oil under it and one does not.

 

[Beachbummer]

how do the springs and guillotine look? a good cleaning might be all they need, but I'm out of my depth on these. I run my seadoo 2 stroke questions by https://www.seadooforum.com/ they are a helpful bunch. (not like here of course, but close )

 

[sn1perii]

Test your cylinder compression. You may have toasted a piston. Had this issue on a Yamaha 2 stroke. Had to get a new top end. Happens sometimes on two strokes especially if you have oil injection.

 

[Patrick Nelson]

The springs and guillotine look fine to me but I am far from knowing what to look for. I actually have a thread open on that other forum as well, figure the more the merrier

I don't know how to test the compression and most likely don't have the tool, but I am on the waiting list for a good mechanic I know to look at it, hopefully this weekend.

 

[Cobra Jet Steering LLC]

look at your plugs if one is damaged or the end is closed you may have lost a piston what color are they ? if one is silver you sucked in water and lost compression in that cylinder, my guess is you lost a cylinder but it's just a guess based on the limited info, spark plugs are the report card for a 2 stroke.

 

[Patrick Nelson]

Thanks for everyone's help. It turned out to be the wear ring, it was pretty much completely gone. I bought these skis used and apparently it had been a long time since it was replaced. The oil leak turned out to be to be a valve o ring and base gasket according to the guy that did the repair. The bellow was fine.

 

[Ron@Scarab]

My jetski ran fine for a few hours yesterday, then suddenly lost power. Would not go past 20 mph. It revs up normally but just doesn't seem to have much power. There is oil splatter around one of the cylinders. Any idea what is going on or what to start looking at? I don't know very much about engines. I attached a picture and can add more if needed. Thanks in advance for your help.

I was going to say to check your wear ring. If you have oil leaking or running down the sides of the cylinders, replace the the 0-rings and paper gasket soon before you melt everything else and it costs you more.