97 GTX mid range bog

[AKnarrowback]

Hi guys.

The GTX is running great, I just swapped out the carbon seal for an old style bearing and seal.

One problem I'm running into is after running the motor wide open for a minute or more then gradually letting back on the throttle and bringing the throttle back up again the motor refuses to rev back up. If I let off on the throttle all the way closed and nail it wide open things rev up normal and it takes off like a rocket.

Rave valves are clean, burning brp synthetic, bellows and springs are good, red adjusters are set flush with the rave caps, gas port is clear. I'm 99% sure it is the raves hanging open with the gradual throttle decrease giving me a high port at too low of an rpm, but I wanted to get opinions on it.

What I'm not super familiar with is if the water can valve and rave valve adjustments interact enough to cause this drastic of a running condition. Also, where does everyone run the caps in relation to flush (in or out). I'm guessing increasing the rave spring tension will help the valves close sooner when the throttle is brought down gradual and have them set up to work at the lower rpms to let the motor rev back up without bogging for 10 seconds.

 

[JeremyD615]

The raves definitely have a significant effect on mid range performance if they are opening early or staying open. I ran mine without the caps or springs for diagnostic purposes, and with the throttle wide open, it would only rev to about 4000 rpm until you got the pump unloaded, and then it would run strong one it got the revs up. I can’t say for certain what’s going on in your case, but it’s a definite possibility that low spring tension in the rave assembly will cause the motor to hang at a low rpm. I’m sure someone else will respond and give you some more guidance, but I hope my experience helps clear it up some...

 

[etemplet]

When did you rebuild the carbs last? Where is your pop-off setting? Maybe your getting a little too much fuel. Where are your high speeds set? Why would the raves hang up unless of course they are dirty or the gasket is pinching one or both? I don't think it's your WCV.

My 2 GTXs gave me the fits with the transition from 4K - 5K. My wife's ski was the worst. She'd get up to 35mph and no more. Then back off a bit and nail the throttle. Sometimes it worked and the ski took off, running like a raped ape. Once she'd get below 3500RPM.... here she'd go again. Comparing two skis side with the same settings was revealing. Carb settings cleared that up for the most part.

 

[AKnarrowback]

Carbs are good, pop off was checked three tanks ago.

The motor sounds like it is getting loaded, like being in too high of a gear. Bogging was probably the wrong word for this situation.

I'm going to turn the cap adjustment in a hair on the next ride and feel things out.

I remember people talking about rave valves with grooves milled into them, but not the specifics. Can anyone shed some light?

 

[AKnarrowback]

HA! I just hit 223 messages, going for 556 then 308.

 

[etemplet]

Did you do the carbs? I can tell you, I fought this with tenacity last year. Pop-off PSI and where it re-sets and holds is critical. 38psi is where it needs to be and it better reset quickly and hold tight around 30psi. I like 30 anyway. above 25 for certain. If this isn't working you'll get fuel when you don't need it.

I have posted many times about the rave valves and my adventure. Someone was kind enough to post a bulletin from SeaDoo regarding customer complaints about the ski bogging in the transition (The poster was kmarts) I found the post and listed it below. I followed the directions and my wife's ski ran so much better. Came on much stronger. The fix is an updated valve body and slotted raves. I also noted that some of the bellows are thicker than others which I believe will affect their performance. I went back with some red ones I found in my stash in and put those in my ski.

Here are some threads. I was a real rookie last year but I'm a searcher. I've upgraded myself to amateur. LOL Good Luck !!

These were good discussions.

Carb Issues (See post #55 under this thread for the technical service bulletin on the Raves) Posted by "kmarts"

Rave Valves Goin Deep

96 787 Very rough midrange.

 

[GGuillot]

Pop-off PSI and where it re-sets and holds is critical. 38psi is where it needs to be

Both of my skis with 787's, pop off is around 34-35psi on the carbs. What's worked for me is being through doing the carb rebuild, using oem kits, new needles/seats and either replacing or confirming the blk 80 gram spring. Carbs sync'd properly and 1 turn on the lows and 1/2 turn on the highs to start out, fine tune from there, which for me has been tweaking only the HS needles.

Raves set flush, I have the stock non grooved raves and top powerband on both skis comes on at about 5000k.

If your carbs are good, I'd try fresh spark plugs and see if that helps.