help im stumped

[kahuna131]

i have a 1996 seadoo gtx i just replaced the motor with a rebuilt one from a local seadoo mechanic that builds them on the side also replaced all the fuel lines and rebuilt the carbs with oem carb kits the issue i was having is under throttle around 4000 rpm it starts to stutter and wont excelerate but if i let off the the throttle idles perfectly was going through a lot of fuel and some times it jumps right up on plane and runs very well so the seadoo dealer asked if i replaced the needle and seats as the ski sat for ten years before i got it so i replaced the needle and seats and the dealer set the pop off pressure for me i put the carbs back on and ran it for an hour yesterday and no issues today i took it out and it ran fine for about 20 min and then under throttle it started to stumble like it was missing i brought it back to idle again idled fine let it idle and tried a few times to excelerate would go to 4000 then stumble then i hit the throttle again jumped right up on plane and ran fine for an hour or so could not duplicate the issue running fine could it be the rave valves hanging up

 

[dieselndoo]

Pop the caps off the raves and watch. Or, try fuel switch to RES

 

[Mekanix]

Not the raves. They only open after 6000.
Check for air leaks along the fuel lines.

 

[mikidymac]

Not the raves. They only open after 6000.
Check for air leaks along the fuel lines.

RAVES open about 4,000-4,500 depending on the spring setting not 6,000.

 

[Mekanix]

Depending on how you hit the throttle. Rev it slowly and they start to move at around 6000. Hit it fast and they open sooner.
I've watched mine do this several times while adjusting the caps.

Does it feel like it is only running on one cylinder when this happens ?
Also have you changed the plugs when it acts up to see if it's just a fouled plug ?
I've had a 96 gtx do this only to find two fouled plugs and fuel in the fuel pump up to the top.

 

[NickCawks]

I had a very similar issue with my 95 xp that I had just put a new motor in and rebuilt the carbs. Turned out to be pop off pressure being too high.

I had followed a chart that Miki had posted at one point according to the chart my pop off needed to be around 40. I don't know if it's the alititude where I am at but I ended up adjusting the pop off 3 times finally ending at 33-35 psi on each. She ran great after that.