Won't go past 20 mph

[nelsonpatrick]

My jetski ran fine for a few hours yesterday, then suddenly lost power. Will 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.

 

[Coastiejoe]

If it revs up as it should, you likely have something in the impeller and or the wear ring is damaged. If it didn't rev up, then it would be an entirely different issue.

 

[pwgsx]

Check the rave valve by removing the retainer clip and black cover. See if the rubber bellow is split or fell off............Check engine compression and check that you have spark on both plugs.

 

[nelsonpatrick]

Thanks for the responses. I will look at all the ideas when I get home from work tonight.

 

[nelsonpatrick]

Nothing in the impeller. One of the rave valves is soaked in oil, that is where the oil splatter is outside of the rave valve in the picture. I took both caps off and nothing looks damaged, just one has a lot of oil in it and one does not.

 

[jjsinaz]

The rave that has all of the oil on it has a bad bellow...guaranteed. Sometimes the bellow gets a crack in it and it's hard to see at first. I had the same thing happen. Black oil splattered in the same spot as in your pic. Couldn't see the hole until I removed the bellow and flexed it some. I doubt that is why you are only getting 20MPH though

 

[Coastiejoe]

There is a good chance there was something in the tunnel and it fell out when you pulled the ski. Very common.

 

[nelsonpatrick]

Thanks I will check the bellow tomorrow in the daylight. As far as 20mph, I know the wear ring needs to be replaced, as in there is not much left of it. My other ski needed one as well but it would just slowly build speed but eventually get to 55mph. This one will not go past 20mph now no matter what. Could a wear ring issue go from no problems at all to not going past 20mph suddenly like this?

I hope it is as simple as something falling out when I took it from the water. I will have to wait until this weekend to see if that is all it was.

 

[nelsonpatrick]

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.

 

[Mickirig1]

Cool, no major repair!

 

[soccerdad]

Looking at your picture, you still have the gray fuel lines in that ski. These are a real problem as the react with today's fuels and will plug your carbs. This will blow your motor very quickly. You need to replace those lines with new ones and rebuild your carbs. Also you should clean or replace your fuel selector. There are hundreds of posts on this site about it. Search "tempo" fuel lines.