1998 XP Limited only 6000 RPM

[bawray]

I bought a 1998 XP Limited a couple months ago. I replaced the grey (green gooey on the inside) fuel lines and rebuilt the carbs (also green and gooey on the inside). I used a Mikuni rebuild kit with Mikuni needles and seats. It runs fine (not as crisp as my HX though) up to 6000 rpm but stops there and will go no higher. I don't know the speed (pickup broken) but I know my (stock) HX is faster (my buddy and I had a race on the water and the HX is maybe 2 or 3 mph faster). I have been reading on the forum and I believe I should be getting at least 7000 rpm and the XP should be walking away from the HX. I have never ridden a 951 before but it seems it should be quicker and faster than what it is.

A couple bits of info...

1) when replacing the fuel line I replaced the inline filter with a new (larger) one from an auto parts store.
2) there is a rattle at low rpm coming from the impeller area when the ski is in the water (I have not removed the pump and have no idea what the wear ring or impeller look like)

Any thoughts on how to get the ski back to full speed?

 

[FL-Rider]

You could try putting the stock fuel screen back in. The automotive filter might be restrictive, especially if a little water or condensation gets in the fuel.

If you're hearing a rattle in the drivetrain while the ski is in the water, it could be the coupler dampers. If you see red rubber/plastic chunks in the bottom of the hull, that is a sign. Remove the PTO cover behind the engine and check the front coupler damper. Then remove the rear driveshaft cover located in the rear hatch to check the rear one.

 

[POPPS]

Just a small notion,,,when you pull the throttle to the bar,,,are your butterflies fully open?

 

[bawray]

You could try putting the stock fuel screen back in. The automotive filter might be restrictive, especially if a little water or condensation gets in the fuel.

If you're hearing a rattle in the drivetrain while the ski is in the water, it could be the coupler dampers. If you see red rubber/plastic chunks in the bottom of the hull, that is a sign. Remove the PTO cover behind the engine and check the front coupler damper. Then remove the rear driveshaft cover located in the rear hatch to check the rear one.

The stock fuel screen wasn't removed. When I purchased the ski there was an additional inline filter so I replaced the old inline filter with a new one. The new filter is larger than the filter I replaced so it shouldn't be restrictive but maybe it is too large? I think I will try removing it to see if it makes a difference.

I have not seen any sign of chunks of the coupler in the hull. I will look closer to see if any chunks are there.

The "rattle" is a very familiar sound I hear in many skis. It seems like the impeller is a little "free" when the motor isn't turning fast enough to put any torque on the driveline. I know there are "anti rattle" nose cones (which my ski must not have). I guess my question is: is the rattle a sign of a worn wear ring? Or, is the rattle a sign of something else that could be causing a drop in performance?

 

[bawray]

Just a small notion,,,when you pull the throttle to the bar,,,are your butterflies fully open?

That was my first thought. Before my last ride I took out all the play in the throttle cable. I am pretty sure I am opening the butterflies now. I can feel the "stop" of full throttle in the thumb lever.

 

[FL-Rider]

The stock fuel screen wasn't removed. When I purchased the ski there was an additional inline filter so I replaced the old inline filter with a new one. The new filter is larger than the filter I replaced so it shouldn't be restrictive but maybe it is too large? I think I will try removing it to see if it makes a difference.

I have not seen any sign of chunks of the coupler in the hull. I will look closer to see if any chunks are there.

The "rattle" is a very familiar sound I hear in many skis. It seems like the impeller is a little "free" when the motor isn't turning fast enough to put any torque on the driveline. I know there are "anti rattle" nose cones (which my ski must not have). I guess my question is: is the rattle a sign of a worn wear ring? Or, is the rattle a sign of something else that could be causing a drop in performance?

If its rattling in the water, I would find out why before riding it again. I would pull the pump and spin the impeller by hand to see how the bearings are. Also, I would check to see if the driveshaft end bumper was still in there. Then, I would remove the cone to see if the anti-rattle pusher and spring were good. The 98's do have them. While you're doing that, see if the jet pump oil looks contaminated with water.
As for a worn wear ring, It won't give you an rpm drop, but you could lose some thrust.

 

[Whus02]

Make sure your rave valves are opening

 

[bawray]

If its rattling in the water, I would find out why before riding it again. I would pull the pump and spin the impeller by hand to see how the bearings are. Also, I would check to see if the driveshaft end bumper was still in there. Then, I would remove the cone to see if the anti-rattle pusher and spring were good. The 98's do have them. While you're doing that, see if the jet pump oil looks contaminated with water.
As for a worn wear ring, It won't give you an rpm drop, but you could lose some

I will pull the pump and check things out. I didn't know the 98 XP Limited had an anti-rattle cone. Thanks for letting me know. I will check the impeller too.

 

[bawray]

Make sure your rave valves are opening

Ok. Thanks. I will search for a thread on how to do that.

 

[Lothsahn]

Ok. Thanks. I will search for a thread on how to do that.

Super easy to do. Make sure they're nice and clean, and clean them every season.

 

[Mraw]

Make sure raves are opening, a 951 will hit around 6k with them not opening, also check out the water regualtor but my bet is the raves not opening. Max rpm should be 6850 or higher.

 

[mikidymac]

Get rid of that inline fuel filter, you could be running lean on top end.

 

[bawray]

Still trying to figure out the 98 XP Limited and why it is only turning a max of 6000K RPM.

I removed the inline fuel filter and I removed both rave valves and cleaned them. Still only 6000k rpm.

I removed the pump to check the wear ring...I am getting .026 inches of gap at 3 and 9 o'clock and .010 at 12 and 6 o'clock on the wear ring. I am assuming the .026 gap is telling me I need to replace the wear ring (true?) but is it normal to have this type of uneven wear? Do I need to replace the impeller shaft bearings?

Also...I have mentioned earlier I have been hearing a "rattle" when I am returning to the dock and I back off the throttle to idle. The rattle will go away when I throttle up a little and the impeller speeds up. It seemed to me like something in the drive line was loose. I have been wondering about the rubber between the motor and the front drive shaft and rubber between the drive shaft and the coupler. I removed the nose cone to check the anti-rattle device and it seems to be working fine (it springs back maybe 1/4 of an inch and the bumper was on the shaft as well). However, with the pump out I can spin the drive shaft back and forth for the impeller about 1/3 turn before the it engages the motor and stops. When I turn the shaft I can hear the "rattle" sound clearly...it is the coupler assembly contacting the coupler on the drive shaft. I turned the shaft back and forth many times and I am pretty sure this is the metal to metal rattling sound I have been hearing. I am now guessing I need to replace the rubber(s)...or is this normal?

The impeller looks good and there was plenty of oil inside the nose cone. The oil looked good (no water and it didn't even smell that bad).

 

[Whus02]

Can you confirm your rave solenoid is functioning?

 

[FL-Rider]

It sounds like the rubber dampers might be disintegrated and gone. Its not normal to have play like that. Since you have the pump out, what happens when you spin the impeller by hand? Are the bearings quiet and smooth? Can you feel any play in the bearings? On the wear ring, are all the impeller blades reading the same clearances? Or, were those measurements taken from different blades?

 

[mikidymac]

If your wear ring was bad you would have max rpm and no increase in speed. You are having a different problem with lack of rpm.

 

[bawray]

Sounds like I need to check the rave solenoid. I will search for a thread on how to do that and try to get that done tonight. I will also look at what I need to do to inspect the rubber dampers between the drive shaft couplings. I think I will need to remove the lower shock bolt and see what else I need to do to get in there and get to the dampers.

When I spin the impeller by hand it spins freely, the bearings are good, smooth, with no play. The measurements between the impeller blades and wear ring are consistent for for all three blades at the same locations on the wear ring. The gaps are consistent with locations on the wear ring, not the blades.

 

[bawray]

I found chucks of the old rear rubber damper when I felt down in the support box under the couplings. Red. I think that means it was an aftermarket damper. Luckily I have a couple of the yellow dampers from an old HX I bought for parts. The used HX yellow damper(s) seem to be fine so I am thinking I could just put one of these in the XP. BTW, the front damper on the XP seems fine because the front drive shaft doesn't have any play when I try to turn it back and forth.

I have a general idea on how to do this job...but I would love some advice on this...First, will I be able to fit the new rubber damper between the front and rear shafts without removing the rear drive shaft that goes in the impeller? Can I somehow access the coupler without removing the shock support? Will I have to remove the entire support box? Will I have to losen all of the 8mm lock nuts on the support ring? Will I have to realign everything? This looks like a job where I might remove way too many parts I really don't need to remove OR I might waste lots of time trying to do the job without removing everything.

 

[mikidymac]

You really should buy a new dampener. When they go you will destroy the expensive driveshaft and PTO.

You have to remove the cover plate on the shock support and I would get the shock out of the way.

Then remove the driveshaft and the rear coupler will fall out of the way allowing you to move the front driveshaft back enough to change the rubber coupler.

 

[bawray]

Ok, and I really hate to write this (I don't want to jinx it) but replacing the rear rubber coupler damper actually wasn't too bad at all. I removed the cover plate, removed the pump and the rear drive shaft. I was able to reach in and pull out the rear coupler (btw there was zero red rubber damper left) and then insert a new rubber damper and then replace everything. Looks good to go.

And I was wondering...unlike the HX there wasn't a clip or a carbon ring...there are two bearing carriers...I guess the aft seal on the second bearing carrier is keeping out the water instead of a carbon seal???

I didn't replace the wear ring as the max. gap was .026 (less than the limit of .040).

Now back to the Rave value issue...after inserting the rubber damper I started the ski to check the raves (with NO rattling from the drive line) and ran it on the hose on the trailer. I revved it to 4-6 grand and checked for any air coming out of the small hose between the rave solenoid and the rave valves. Nothing! So absolutely nothing to push the raves up.

I ran out of time to do anything else but I think I need to check the hose coming into the solenoid next. So...

1) If there is no air coming in then what next? On a brief inspection this line looks like it is going from the rave solenoid to the rear of the ski. However the parts diagram shows it going to a check valve connected to a hose coming off the crankcase. I am guessing either the check valve is bad or the hose has worked itself off a fitting somewhere. Will I need to remove the airbox to get under there to get to this check valve?

2) If there is air coming into the solenoid then the electric connection must be the problem. What is the connection to? Any fuses? How to proceed? I can trace it back tomorrow but then what?

 

[Mraw]

You can cut a notch or hole in your rave valve caps to see them move up and down. If they don't open then check your check valve and then solenoid, you can apply 12volts to it and you should be able to hear it click on. Remove the airbox and you will see the check valve, it's on a brass fitting on the PTO side

 

[bawray]

I don't feel any air coming from the line BEFORE the solonoid (from the crankcase). Should there be a "good" flow coming from this line? I can feel it vibrating for sure but I don't feel any air pressure at all. I even tried blowing in it and drawing air from it. It doesn't seem to want to let air flow in either direction. So...I am assuming the check valve is clogged and needs to be replaced. I have the airbox off and I can feel the line with the check value. BUT...how the heck will I ever get a clamp back on this line???

 

[bawray]

And...the local Sea Doo dealer is closed until Tuesday. Are there any options for this check valve (part # 275500417)? For instance, can I get one at an auto parts store that will work? Will the check valve for the fuel tank on the HX work (I have two of those...part # 275500398) as I am assuming the check value for the line going to the rave solonoid only lets air flow in one direction.

 

[Mraw]

You can use a zip tie on the line, as for the check valve try cleaning it out. I don't know what alternative to use if you need a new one, hopefully someone will chime in

 

[bawray]

I removed the check valve, cleaned it (brake cleaner would steam straight though), and replaced it back on the ski. I did use a new 1/4 hose to attach it to the crankcase as the existing hose seemed old and brittle.

Cranked the ski and now I can feel air pulsing from the hose (through the check valve) from the crankcase. However, I don't feel air leaving the solenoid and going to the raves.

I unplugged the electrical connection to the solenoid and put a volt meter on the plug going to the solenoid. Started the ski and revved the motor. I saw the voltage spike up a couple of times. It was difficult to rev the motor and hold the voltage meter at the same time so I don't feel too good about my results here but I think it is getting current.


I removed the solenoid and connected one of the electrical terminals to a positive lead directly from a fully charged 12V battery and connected the negative lead to the other battery negative and I didn't get anything. No click. Nothing. While the current was on I tried blowing break cleaner through the inlet from the crankcase and it is still closed. Is that the correct method of testing the rave solenoid? I hope so because I just ordered a used solenoid off Ebay.