Seadoo xpl 1998 947 max rpm

[freddy090]

hello guys, i am using a translator to talk to you, excuse me if i speak bad english!
I have a 1998 xpl 947 engine which does not exceed 5500 to 6000 rpm 75 to 80 Km/h (gps).
I checked everything:
Carburettor cleaning, new mikuni kit gasket, pop off 21 psi jet 80 160, all new hose, selector checked
Rave valve new, check valve checked, the valves open correctly
new carbon petal
New Ignition coil, new spark plug
Water valve seal new and working properly
New piston and ring, cylinder deglazed 129 psi and 131 psi, my compression gauge may not be properly calibrated
New propeller and wear ring
Mpem and key changed, it's still the same.
I no longer use the oil pump, I make a 2% mixture.
Tank completely emptied and clean
I tried to change the jets up to 75 and 150, I got 6000 rpm but my carburation was too poor
the engine responds very well to acceleration and has good torque.
the throttle fully open the carburetor
I saw on the forums that many were blocked at 6000 rpm but no one has provided a solution
I am desperate...

 

[POPPS]

Sounds like fuel depravation,,,do the butterflies open fully?,,,selector can’t be checked..only replaced,,,remove it from your equation,,,by running a line directly from the water separator to the carb,,,do the rav valves open fully,,l

 

[freddy090]

yes the butterflies open fully , the selector allow fuel to pass well, it's clean inside, I tried to remove the springs from the rave valves to test but that's not it

 

[FL-Rider]

The concern with the selector is not just whether it passes fuel but rather if it allows air to be sucked in through the stem seal since the supply side of the fuel system is under suction. Popps is saying bypass the selector valve with splice connectors and a short line so you can determine if that's your problem. Of course, cap the reserve line from the tank if you use the main line as your supply. Alternatively, you can run a direct line straight from the tank, but on your model its a little bit of work to access the tank since its under the seat.
I have a short clear urethane line spliced into the return line coming off my carbs so I can observe bubbles in the line. You could also use a temporary clear urethane line from the filter screen to the carbs to look for bubbles in the supply.

 

[JC-SUPERJET]

Did you use Genuine Authentic Made In Japan Mikuni Carb Rebuild Kits? That's the only Correct Kit to use.

How old are the RAVE Valve Bellows? Old Bellows will begin to leak pressure not allowing the Valves to fully open and thus never reaching Peak RPM.

Are you still using the Solenoid managed OEM RAVE Valve System? The Solenoid can be going bad.

Is the Solenoid Vent Hose or Outlet plugged, blocked or clogged?

What about the Check Valve in the RAVE System, located between the Solenoid Valve and the Crankcase, is it leaking? Have you inspected it to see if it only allows Air thru one way?

With the Ski on the Trailer in the Water, with Throttle wide open, manually Lift the RAVE Valves and see if you gain more RPMs.

Maybe Water is dripping on the Intake from the Exhaust? Is there an Exhaust Water Leak?

What about the Valve on top of the Waterbox? Is it leaking or going bad? That can affect performance too.

Is Cooling Water from the Cylinder Head leaking into the Cylinder Bores on top of the Pistons? How old are the Cylinder Stud O-Rings? How old is the Cylinder Head Gasket?

Have you tested the Stator? The Regulator/Rectifier? The CDI draws the Spark Energy directly from the Battery. If the Battery is weak and/or is not being charged during operation, it will not be able to supply enough Spark Energy needed for high RPMs at fully open throttle.

If all the above checks out, then it's probably an Engine Air Leak. Perform Air Leak-down Test.

You have more work to do : )

 

[freddy090]

thank you all for your help, I will try to bypass the selector and I will check if there is an air leak in the lower engine, the only 2 things that I have not tested yet

 

[Boyd12]

what do the spark plugs look like? Is it running lean or rich?

 

[freddy090]

My spark plugs is brown with main jet 155 pilot jet 75 and Black with main jet 160 pilot jet 80 , and white main jet 150 Pilot jet 75!
I test this weekend bypass selector and filter oem

 

[mikidymac]

Did you rebuild the carbs with only Genuine Mikuni parts including new needles and seats?

Stop messing with the jetting, a stock seadoo will run perfectly with stock carb settings at sea
level.
Main Jet: 160
Pilot: 80
Spring: Special 951 95 gram
Needle & Seat: 2.0
LS Screw:1-1/4
HS Mag: 0
HS PTO: 1/4

Have you checked the throttle position sensor per the service manual?

 

[freddy090]

Yes i have rebuild the carbs with only Genuine Mikuni parts and new needles and seats.

I reset the original carburettor setting

What the throttle position sensor? I don't think I have any on mine

 

[mikidymac]

I am not sure if yours has it but it would be a box on the throttle cable where it splits to the oil pump. It changes the ignition timing at 80% throttle opening. On models that have it you can loose about 1,000 rpm on the top end if it isn't working, my 01' XP has it.

 

[FL-Rider]

My 98' xp doesn't have one

 

[freddy090]

Test today bypass selector and filter it's the same 6000 rpm max :-(

Test with other ignition coil , not better

 

[freddy090]

When I rebuilt my carburetors, I did not do the test in the manual for the injector check valve which should open at 13 psi in the xpl 1998 1999 manual and at 2.8 psi in the 2001 manual.
I tested them and they open at 0 psi. Will my problem be that these injector check valve lets fuel through at high rpm which would make my mixture too rich and which does not make me exceed 6000 Rpms?
I will test the removal of the fuel accelerator pump and the clogged hoses in the next few days.

 

[Spyder917]

Glad I found this thread. Coffman piped 1998 XPL. Ran fine two weeks ago. Took it out one day and would only rev to 6000. Checked ecwi, rev limiter, carbs. Almost gave up on her. While reading above, POPPS suggested to check Rave valves. This is one thing I overlooked. Opened up mag side, no issues. Opened up PTO side and bellows/spring had slipped off. Fixed the valve and bam, 7500 RPM pulling very hard. Thanks POPPS!