96 GTX Rev Limit Problem

[chrisny454]

The Problem:
96 GTX will not rev past 3000-4000 in the water after 5-10sec... However, it will rev all the way up as soon as I start it, then it will rev 5000-6000 next time I WOT, then finally it will not go past 3000-4000 at WOT regardless.

2 years ago I was able to beat the issue by just letting it warm up and gradually bringing up the RPMs. It would finally go past the limit and be usable for the rest of the day. Sad to say I can no longer do this and no matter what I do, I cannot get it the rev past 3000-4000.

The motor sounds like it is bogging or missing so my guess was that the computer's rev limiter thinks the machine is still out of the water. But I dont know what device/system tells the machine that it is in the water or not so I cant check for a faulty device.

I have NOT done the fuel lines nor cleaned the carbs/RAVE valves EVER so I know I need to do this, and that may be what I have to do first. BUT I was wondering about the Rev Limiter and how the ski knows whether or not it is in the water. If the machine thinks that it is out of the water still (Even though it is not) then I am 99% sure the rev limiter will kickin to prevent over revving out of the water.

Thanks for listening to my ramblings and offering any insight you may have.

ChrisNY454

 

[nswillin]

There's not anything that tells the seadoo if it's out of water or not, just you. You didn't mention anything about the sparkplugs, did you check those. I know it's small, but sometimes can be overlooked, make sure plugs aren't fouled and the gap is set correctly.

Go ahead and clean the RAVES and replace the fuel lines to black fuel injection rated hose, like you were planning on doing. Also look at the filters inside the carbs, good chance they are clogged as well.

 

[Nate Surveyor]

The bad part about running it like it is

Is that you are forcing it to run lean.

If all you said is caused by bad fuel lines, then you really had better get out the new fuel lines!

N

 

[JPX]

In 1996, Seadoo had not produced any boats that could tell if they were in the water or not......well other than the mechanism that ANY boat has called sinking.

The "detector" you believe is limiting the revs is the actual load of the water on the impeller in the jet pump. When it freewheels in the air, there is no resistance and very little engine effort is needed to turn the driveline.

As soon as you put it in the water, all of the bearing surfaces become loaded, and the effort the engine requires increased dramatically......kind of like kicking you legs on land is easy, but much more difficult in the water.

Since the engine load increases in the water, the fuel demands, the spark demands, and the compression demands increase. So you can get the engine to run on restricted fuel in the air, but the fuel delivery is not enough to run properly in the water.

 

[seadoosnipe]

Fuel lines........

Sounds like your leaning out. This can be determined by inspecting the plugs when you've been running for a while. You must kill the power, open up the engine and take them out then. If you allow the engine to go back to an idle, then you'll not get a true reading of the plugs or the engines condition.

As nwillin and Nate have said, you need to get rid of the grey lines, clean out the carbs micro mesh filter and clean your rave valves. You should also check to make sure your carbs are syncronized properly. :cheers: