01 951 GTX DI pump noisy and slow acceleration

[pilot650]

The pump is much noisier when idling on trailer but quiets down with a little throttle application. I have two of these skis, and this ski is much slower to accelerate and has a top speed about 4 mph less than the one with the normal sounding pump. Engine runs smooth but it seems to be cavitating off the line, or like it was pulling a heavy load. Is this a bad impeller, bearing, pump housing or what? Is there a pump rebuild kit that would likely fix the rattle and slow acceleration? I am attaching a video of the idle rattle. Any helpful input is appreciated!
noisy pump video

 

[mikidymac]

Seadoo pumps are inherently noisy even when perfect due to the design.
You should pull the pump and inspect the impeller, wear ring, change the oil and check for water contamination and bearing smoothness.

The only thing you would need is pump oil, permatex 518/515 sealant and a cone o-ring once it goes back together. I would wait to buy anything until after you take it out and inspect to make sure you don’t need anything additional.

 

[pilot650]

 

[mikidymac]

Ouch! You can have the impeller refurbished by Impros but you are going to need a new pump housing.
I would check with Westside Powersports Seadoo and see if they have a good used one.

 

[pilot650]

Will a pump rebuild kit suffice or is it because the vanes are chewed up that it needs to be replaced? And what you see would cause the sluggish acceleration?

 

[mikidymac]

Yes because the stator is chewed up.
The stator being damaged and the wear ring will absolutely make it not accelerate at all.

 

[pilot650]

So I bought a used pump off of eBay supposedly from the same year and model but it has a brass stator. Steering nozzle seems to match up so I guess these are interchangeable but curious is this a newer version of the pump? Seems it would’ve been a good choice and be more durable being brass. Also, how do I remove the wear ring? My original pump had a wearing that had screws holding it in place, this new pump does not have anything securing the wear ring.

 

[mikidymac]

The brass pumps are older. The plastic ones actually loaded the engine more.

 

[pilot650]

Hmm. I looked at the auction again and it was supposedly from a 2002 GTX DI. I have a 2001 GTX DI which has a plastic pump. Still should be an improvement from what I was working with if I can figure out how to change the wear ring. Even as it is there is much tighter clearance with the impeller than my original.

 

[mikidymac]

eBay is notorious for the wrong listings and applications.

 

[pilot650]

Are the splines supposed to be tapered like this?

 

[pilot650]

I looked up pictures of the driveshaft and that looks normal. I took the new pump, new wear ring, new impeller, new neoprene seal, new tail cone anti rattle kit and installed it back into the ski. Plugged up the battery showing 12.5 V. Go to turn it over and it won’t turn over, just engages the starter. I’m assuming this has to be something wrong with the pump, but I don’t know what it could be. Perhaps the impeller wasn’t screwed all the way down? Some of the impeller blades and the nosecone stick out above the pump housing, but that seemed to be the same case in my old pump.

 

[mikidymac]

It is easy to pinch the thrust washer on the pump shaft when installing the impeller. This is the most common issue when rebuilding the pump. You are going to have the pull the pump.

 

[pilot650]

I loosened the pump a bit and the engine will turn over now. However, when it runs it’s just as noisy as it was with the old pump even though everything is new, even a new pump housing. Could this mean the driveshaft is warped potentially? The thrust washer, is that the rubber nose cone on the impeller that you’re speaking of? Should I remove the little rubber cap off the end of the driveshaft? If it’s binding preventing the engine from turning over, it seems like the pump is on too tight.

 

[pilot650]

Terrific! Well I tightened the pump up a little bit more, it’ll turn over and start but it seems the RPMs are a little slower like it under too much of a load. Go to the back of the ski and there’s shredded plastic, must be the new wear ring? Maybe the neoprene gasket getting shredded? What is out of line?

 

[mikidymac]

The new wear rings are a tight fit and the impeller will shave them to fit.
It is always good to spray them with some WD-40 before first startup.

 

[pilot650]

It wasn’t shaving until I tightened it more, which still has a gap between the pump housing and the hull. The shavings are rubbery so hopefully I just shredded the neoprene gasket. Maybe it says in the manual how to torque it but it seems you would want the pump on pretty darn tight. However, it seems that the tighter it goes the more it binds up the engine. Is there something else that could be wrong? And still not sure why pump is so much nosier than my other ski even though it is all different parts.

 

[mikidymac]

I think you have something wrong with the rubber seal. Tightening the pump shouldn't have any effect on the impeller spinning and there should be no gap between the pump and hull.

 

[pilot650]

I looked in a manual and it says the pump to hull studs should only be 24 ft lbs which is nearly nothing. I'm sure I put them on several times more torque than that using an impact gun, which crushed the neoprene ring gasket making it bulge and get in contact with the impeller causing it to shred. When it was fully tight the engine wouldn't even turn over. So I will replace the neoprene ring and use a torque wrench and see if it runs without shredding.

It also seems like very little oil would go into the tail cone and the manual says around 100ml should go in.

And, there is still a hell of a lot of rattle noise in the driveline despite any visible wobble in the driveshaft.

 

[mikidymac]

Did you grease the splines on the driveshaft?
Did you fill the pump cone with oil to the bottom of the plug threads?
Did you see if your pump cone has the "pusher" that you need to push down to relieve the spring pressure on?

 

[HawkX66]

I looked in a manual and it says the pump to hull studs should only be 24 ft lbs which is nearly nothing. I'm sure I put them on several times more torque than that using an impact gun, which crushed the neoprene ring gasket making it bulge and get in contact with the impeller causing it to shred. When it was fully tight the engine wouldn't even turn over. So I will replace the neoprene ring and use a torque wrench and see if it runs without shredding.

It also seems like very little oil would go into the tail cone and the manual says around 100ml should go in.

And, there is still a hell of a lot of rattle noise in the driveline despite any visible wobble in the driveshaft.

This sounds suspiciously like what I'm up against right now. I think you'll find the bronze part where the thrust washer sits is thicker than the factory pump for our machines. This is causing the impeller to get tightened against the housing instead of tightening against the impeller shaft. Have you had a chance to sort yours out yet?

 

[pilot650]

Hmm. I have not sorted it yet. Took the pump off thinking the neoprene ring might have been shredded and it was fine. Shaved off some pretty good pieces of the wear ring though. It is noted that the new impeller in the brass pump doesn't spin as freely as the old impeller in the plastic pump, but that also could be due to the tight fitment of the wear ring. I got a new neoprene ring while I was waiting and had to use silicone adhesive and zip ties to try to get it to stay in place, and plan to grease the impeller and driveshaft, put the pump back on the ski tomorrow and torque only to spec and see where the chips fall. From what you are suggesting, would that mean we potentially need a different impeller to fit the bronze pump from a different year model? I did the research to see if there are different part numbers for the impellers of different year GTX DIs, and they are all the same, even the XP DI uses the same impeller. So it seems that's not the issue.

 

[HawkX66]

Hmm. I have not sorted it yet. Took the pump off thinking the neoprene ring might have been shredded and it was fine. Shaved off some pretty good pieces of the wear ring though. It is noted that the new impeller in the brass pump doesn't spin as freely as the old impeller in the plastic pump, but that also could be due to the tight fitment of the wear ring. I got a new neoprene ring while I was waiting and had to use silicone adhesive and zip ties to try to get it to stay in place, and plan to grease the impeller and driveshaft, put the pump back on the ski tomorrow and torque only to spec and see where the chips fall. From what you are suggesting, would that mean we potentially need a different impeller to fit the bronze pump from a different year model? I did the research to see if there are different part numbers for the impellers of different year GTX DIs, and they are all the same, even the XP DI uses the same impeller. So it seems that's not the issue.

I'm really not sure what the deal is. These are new to me so all I'm doing is following the service and parts manual. The measurements I took today only told me what I needed to know about the parts I'm working with. Luckily my original housing is salvageable and I'll be able to rebuild it. I ordered a new bearing and seal kit that will get here Saturday. If I'm successful, then I'll know it was the housing. I know for a fact it has nothing to do with the wear ring in my case. I don't know what the differences are, but I saw the GTX Limited has a lot of different parts.

 

[HawkX66]

I've confirmed the bronze pumps we're working with need a different impeller or impeller shaft. I haven't seen different ones yet that mount differently. I'm sure they're easy to locate if you know what you're looking for. I received a NOS impeller # 271 000 929 yesterday which is just the "High Altitude" impeller for our machines. Just like my stock spec QC 000 023 it didn't fit the brass pump.
I'd like hear from anyone that's successfully running the bronze pump housing with cast number: 271 000 873

 

[mikidymac]

I've confirmed the brass pumps we're working with need a different impeller or impeller shaft. I haven't seen different ones yet that mount differently. I'm sure they're easy to locate if you know what you're looking for. I received a NOS impeller # 271 000 929 yesterday which is just the "High Altitude" impeller for our machines. Just like my stock spec QC 000 023 it didn't fit the brass pump.
I'd like hear from anyone that's successfully running the brass pump housing with cast number: 271 000 873

It's possible it's the impeller shaft but I can't say for sure.
The brass pump uses impeller shaft #271000886
The Plastic pump uses shaft #271000965