97 seadoo speedster fluctuating rpm

[sv650racer]

Hi all,
I have a 97 seadoo speedster. I have a problem with one engine, it idols fine, but when it first starts up it the rpm fluctuates. The other engine runs fine. This only happens for the first 5 mins or so. Then it runs normal. I would also like to note that the problem engine runs at a lower rpm then the good engine when it stops fluctuating.
Any Ideas on what might be causing this?

 

[John in Valley Forge]

When you say fluctuates, how do you mean?

Does it race above the RPM of the other engine, or drop off below?

My left engine generally runs about even with my right when the throttles are together, but sometimes it will drop off by 1,000-1,500 rpm then surge back up. This happens to me around 6,000 RPM. The right engine stays steady at 6,000 but the left bounces from 4,500 to 6,000 repeatedly.

Makes for an unnerving ride and hard steering.

 

[sv650racer]

By fluctuate I mean that it drops down and back up quickly. There doesnt seem to be any set pattern and after a while it goes back to normal.

 

[John in Valley Forge]

By fluctuate I mean that it drops down and back up quickly. There doesnt seem to be any set pattern and after a while it goes back to normal.

Sounds like the same issue as mine. I've had folks on my river tell me that it is a sign that the carb is gunked up and needs to be cleaned. I've replaced all the fuel lines to that engine, cleaned the flame supressor and sprayed a full can of gumout into the carb. That helped for a while but the problem has returned.

I plan to live with it the rest of this season and purchase a rebuilt carb to replace it over the winter. Then probably the same to the other engine.

 

[sv650racer]

Thank you for the reply!

 

[John in Valley Forge]

The reason for replacing the fuel lines is that the new fuel with Ethanol breaks down older fuel lines and the debris and gunk ends up in the carbs. My guess is that it intermittently clogs something in the carb. I really dont know.

What I do remember though, it trying to rebuild a carb for a '74 Dodge Slant Six. I don't ever want to try to reassemble a carb again so I sm willing to pay extra for a good-to-go re-manufactured one.

 

[John in Valley Forge]

I've also found that if I back off the throttle on the offending engine, I can get it to stop, then adjust the throttle on the good engine to match the RPMs. If I'm up on plane, I tend to throttle back anyway.

 

[sv650racer]

with mine it just did it for the first 5 min or so then ran fine for the rest of the day.

 

[WVBubba]

I've also found that if I back off the throttle on the offending engine, I can get it to stop, then adjust the throttle on the good engine to match the RPMs. If I'm up on plane, I tend to throttle back anyway.

My 97 Speedster is doing the EXACT same thing... Curious to see what the problem might be.

 

[John in Valley Forge]

My 97 Speedster is doing the EXACT same thing... Curious to see what the problem might be.

I am just hoping that one or more of the veterans around here read this, recognize the problem and give some advice.

 

[nightrod]

I have been on every forum on the net and everyone is having the same problems with bogging speedster and no one seems to have the answer. mine runs fine at wide open trottle when i first launch it and I can run wideopen till it runs out of fuel but if I slow down it will not go over 4000rpms on both engines. If I hit a wake and the jet comes out of the water it will take off again. Of corse my local shop wants me to bring it in so they can rebuild everyting at a huge expense to me or they said they will gladly purchase my boat. There has got to be an actually solution to this problem and it can't be that difficult to fix. If I don't find it soon I'm going to take my boat out to the middle of the river and sink it.