2000 XP Needs 1000 More RPM

[TLH101]

Got an issue with my 2000 XP. Starts and runs fine, but about 1000 rpm short on top end. On the water it accelerates good, and pulls hard, and smooth, to 5700 rpm, and wont go anymore. Runs about 52 mph on the dream-o-meter. Just replaced all the fuel lines, disassembled and cleaned the carbs and fuel selector. Cleaned filter, new plugs gapped correctly, and pop offs set to specs. Butterflies hit stops, almost, (~.020" clearance). Any idea where to start. I am at 4400 ft and my GTX Ltd will turn 65-6700 rpm.

 

[Wayfaring]

I'm not positive about the 2000 XP, but I had similar symptoms with my 96 XP. The forums pointed me to the water regulator, so I took it apart. I had a broken spring and the lower clamp had rusted and poked a hole in the bellows.

 

[SabrToothSqrl]

Check:
water regulator
RAVES
Throttle Position Sensor (not sure if this was added in 00 or 01) It lives under your oil tank, and you can check it for operation. i THINK it's 5v under 90% throttle, and 0v 91%-100% (or maybe the other way) there are 3 wires. I forget how I tested mine...
check compression
check that the impeller is in good shape, and spins easily on the shaft.
did you clean the fuel filters on the carbs? jets clean?
did you remove and verify the reed valves are in good shape?
you can hit 7k WOT on a PERFECT condition 951.

 

[dean.mohr]

My '00 GTX w/951 was only running about 6600 rpm. Pulled hard and whatnot, but just didn't reach top. Cleaned (didn't rebuild) the carbs and that didn't do it, so I opened the high speed screw maybe 1/8th turn (maybe less) and now it runs 7050 rpm all day long at 57 mph on the GPS.

 

[TLH101]

Pulled the caps and RAVEs were a bit sluggish. Removed and cleaned the old tacky oil off (Ski sat for several years). No carbon build-up. Push the RAVEs down and they pop back up on the diaphragm, so I know they are not stuck. Still only 5700. Pulled the springs out, and as suggested, and it's a bit doggy on bottom end, but tops out at 6400 on smooth water. I tried setting the red caps flush, but no change.
Any idea why the RAVEs won't overcome the springs?

 

[SabrToothSqrl]

...did you check all the other things in my list..?

 

[TLH101]

Problem solved.
Check valve was stuck closed, preventing pressure to reach the RAVE valve housings. Runs about 6600 rpm and pulls hard on the bottom end.

 

[dean.mohr]

Which check valve are you talking about?

 

[TLH101]

The valve in in the pulse line, that connects to the engine, right behind the carb pulse hose.

 

[Marky_Marc]

The valve in in the pulse line, that connects to the engine, right behind the carb pulse hose.

Glad you got it sorted.

The "runs to 5700rpm" is probably one of the most common issues seen with the 951 ski's. Unfortunately, it can be so many different things. Slightly strange how it's always this rpm figure as well.

Anyway, while your down there check the condition of the pulse lines for any creases, holes etc. You do not want a leak in those lines. A leak will cause it to run lean and then boom! I always check mine before the start of the season.