River test show a couple of issues.....

[kenfyoozed]

1997 GTX 787 just finished cleaning the oil system and switching to an API-TC synthetic oil. Rebuilt the carbs as well and followed the manual and the instructions found in the carb thread. It fired up and ran awesome for a while. I was now able to ride over 5000rpm as before it would stumble and die. It had no hesitation at any point. So I assumed the carbs were close enough and I can live with the way they are for now. I want some ride time and then later i figured i would do some plug chops and dial them in spot on, but I'm happy they way they are. The engine pulled all the way to a bit over 7000prm.

Here is the first issue. After a while I could hear, and possibly feel, but it was more audible if you turned your head to the rear to listen for the issue. It was a light "pop", almost what I would call a "miss" with the engine. I could not tell by the tach if it would drop any rpms. I did not install new plugs as the plugs that are in it have less than 2 hrs on them but they were dirty. They were this way before I swapped the oil from a TW3. It was only very faintly noticeable. If i wasn't looking for issues I doubt i would have even noticed. What would cause this?

Second issue... It was running great and then a bad vibration started. I thought I had dropped a piston but the engine continue to rev and respond as normal, other than a vibration. Headed to the dock at about 5000rpm when all of a sudden it smoothed out. Vibration was gone, so I headed back out. I figured i may have sucked up a water hibiscus or something of the sort and it finally got pushed through. This happened a second time. But this time the engine would rev up but the speed would not increase. I babied it enough to get on plane and headed for the dock, about 5 miles away. Made it back. But while on the way i had to slow down a few times and each time i would attempt to accelerate it would bounce off the rev limiter and speed again would slow increase. At this time top speed was considerable less and if i tried i could hit the rev limiter as before the vibration I could not. So I am assuming that the engine is ok but the pump has an issue. Once on the trailer I did pull some vegetation and bark out of the groves between the grate an hull but nothing from the tunnel or around the impeller. I pulled the grate off once back home and took a look inside. There were no objects but I am pretty sure the wear ring need replacing. Here is a picture below. I did not even attempt to measure the gap as the manual says it should be 1mm and this is no where near that... Is this the cause of my loss of speed? If so why did it happen all of a sudden? Speed was there one second and gone the next.

With these two issues what do you suggest as a plan of action?

 

[mikidymac]

Yes, the vibration, bump then cavitation was the rubber surrounding the fiberglass core of the wear ring letting go. This is pretty common on older skis especially ones that have been sitting.

You need anew wear ring and I would also install a "Neoprene Seal" Also a good time to do a pump oil change.

This will fix your issue.

 

[kenfyoozed]

Is there a vendor or type of parts you suggest?

 

[AKnarrowback]

Just to chime in.

Find a local DOO dealer that can get an OEM ring for you, it might cost a hair more but it's worth it. X2 on getting the neoprene ring as well.

7000 +- is the shop manual spec for where the rev limiter is set. If you are showing a hair over 7000 on the tach then I would guess the "miss fire" you hear running wide open is just the limiter doing it's job and bumping the motor off.

I would pull the pump out and give everything a good look. Check the trailing edge of the impeller fins and see if they are bent forward from rocks going through the pump, this is a common cause of bumping the rev limiter.

I have the same machine and had a HUGE vibration, engine reving and bumping the limiter, no hole shot problem show up out of no where and that little piece of swamp grass was the problem. Small changes in the pump can cause big performance changes.

 

[mikidymac]

I also prefer the OEM wear rings.

 

[kenfyoozed]

I figure since i will be pulling the pump i might as well replace everything except the impeller at this point. any special tools i need to order as well other than the impeller tool?

 

[AKnarrowback]

Just the spline tool to spin the impeller off. Just lock the shaft in a vice. Cut the liner with a sawzall type tool and hammer a flat blade screwdriver between the liner and pump to let the cut ends overlap each other and the liner falls out. Make sure the thrust bearing is centered on the shaft before tightening down the impeller.

 

[kenfyoozed]

waiting for the sun to drop for another 30min to be able to work in the shade. I hope to have it off tonight as parts have been ordered. I'll post back with what I find or issues I come across. Thanks again for everyones help.

 

[mikidymac]

If you don't want to remove the impeller you can sometimes put the pump in the freezer for a couple hours and the wear ring will pull out.

 

[kenfyoozed]

If you don't want to remove the impeller you can sometimes put the pump in the freezer for a couple hours and the wear ring will pull out.

I thought of trying that.

I got the pump off. It was easier than I thought. There was no sealant between the pump housing and the hull. I didn't even see the neoprene gasket. I does look like someone has been in before as one of the mounting bolts was missing a washer. I had also removed the hoses from the inside but it turns out i didn't have to do that either. I removed the cone in anticipation of water intrusion but there does not seem to be any water but the gear oil was very dark. I also noticed the is some play in the impeller shaft front to back. Not much maybe 1mm but enough that when you turn the pump over you can hear a clunk as it falls back to the other side. I doubt this is a good thing but i do have all new parts on the way.

Is there a special tool or way to remove the old bearings and seat the new ones? In the past I have just used a socket that is close to the right size. I did get the tool to seat the seal properly.

 

[AKnarrowback]

Sounds like your pump is just fine inside.

The back and forth movement of the shaft you are describing is normal. If the oil is not milky then the seal is probably fine. Take the shaft out and inspect the bearing surfaces, ifvthey are smooth I would not bother replacing anything.

They do make a tool for pressing in the bearings. It supports the inside of the bearing while pressing on the end.

 

[mikidymac]

There is a 99.9% chance your pump is fine. The play is normal and the OEM fluid is black from the factory.

If you do replace the bearings and seals make sure you set them at the exact depth per the manual, yo don't just push them in until they stop. I just use sockets, a press and a digital caliper to do mine.

I think it was @racerxxx that made a bearing install tool.

 

[racerxxx]

Not me, I'm old school. I use sockets, extensions and a screwdriver. Never saw the need for a special tool. The guy who used to make them was out of Florida has a gtx.

 

[kenfyoozed]

Just priced that tool and WOW its expensive!

 

[kenfyoozed]

Got my parts from OSD about an hour ago and promptly went to workrear. I was worried about the impeller being stuck but I remembered I had a torque multiplier I have to use to remove the lug nuts on my tele handler. So got that out and was about to step outside to where my large fab table and vise are when I noticed my drill press table and the t-slots that are on it looked close to the size of the tab on the impeller shaft. Sure enough it was a perfect fit and in less than 30 secs the impeller was off. I was able to drive the bearings out also with sockets. Although after driving the first on inside the pump I realized that there is a larger area between the two bearings. I used another smaller socket on the inside of the bearings to line them up to drive them out. Success! Looks like the shaft was having interference from either the thrust washer or bearing to make these shiny groves that can be felt. Bearings were a bit gritty and hard to move as well. So all new parts going back in. Couple of questions......

1.The kit came with 2 small o-rings where do these go?
2. I do not see a neoprene gasket in my parts diagram. Is this still used on my gtx?
3. Should I put the cone on before or after I have the pump back on the seadoo?
4. the seal I got looks like a basic oil seal, but the on that come off looks different with a solid backside. Is it ok to use the one in the kit or should I order something else?

 

[mikidymac]

The o-rings might be for the bailer tubes on the pump nozzle.
You should use the neoprene seal even if the diagram doesn't show it for your ski.
Cone can go on with the pump out.
The seal OSD sent should be fine.

 

[kenfyoozed]

Just to confirm... Seal goes between pump housing and the hull correct? No other sealants to be used....

Got the old wear ring cut out. I just about an inch wide strip and pried it out and then the wear ring just fell out. So easy enough. Started inserting the new bearings and seal and all seems to have went well. Just worried if the thrust bearing or washer are lined up properly. Hard to tell but I think they are.

I am out of red locktite for the impeller threads, would it be ok to use the blue? I have read that the direction the impeller is turning will always keep it tight but want to confirm before I proceed. I have also read with locket to torque to, manual says 52ft/lb but I have also read about using anti seize and torquing to 90ft/lbs. Which is preferable?

 

[mikidymac]

Yes, neoprene seal and no sealant.

Make sure you set the bearings to the factory spec depth.

I use antiseize on the threads and torque to factory specs.

If you put the shaft in the vise, then install the bearing and washer on the shaft then put the pump over the shaft and install the impeller you don't risk pinching the thrust bearing in the shaft groove.

 

[kenfyoozed]

Got it all rebuilt. I will reinstall tomorrow. One thing I did notice is that the impeller doesn't seem to spin any smoother than before. Its not like its locked up but I had expected there to a lot less friction with all new bearings, shaft and oil. Im sure it all went back as it should and there isevena little axial play on the shaft so i know i did not pick the thrust bearing or washer. I want to test it tomorrow but its supposed to be another rainy day like today with off and on showers. Who knows maybe I'll dodge the showers, because riding in the rain is no fun.

 

[kenfyoozed]

Got it back together after lunch, I thought getting the splines lined up would be an issue but it went smoothly. Hit the water for about an hr to test it out and all went good. Couldn't stay out longer due to the brief window we had between thunderstorms but it was fun none the ess. Too my youngest son with me and we hit a top speed of 49mph verified via gps. I figured there was about 350lbs onboard so thats a respectable number I can live with.

Couple of thoughts while i was riding..... It seems the seed needs about 4000rpm to get on plane and stay there and anything less it seems to just plow through the water. And i would guess being on plane would be about 25mph. I assume this is the way they were designed?

Also the low oil light came on for about 5min then went off. I know when I redid everything I added just under a gallon of oil. What is the oil capacity? and what is the oil consumption? I would think that i should have plenty of oil left. I have only used about 11 gallons of fuel sinceI added the oil.

 

[mikidymac]

The tank holds a gallon so if the system was empty you probably had a little more than half a tank of oil.
The light is just an idiot light with a float in the tank so if it was rough or at and angle when getting on plane the light could come on briefly.

Just by a rough guess, you should be able to get about 4-6 tanks of fuel per oil tank.

 

[noviceskier]

I always keep a spare gallon of oil in my truck, after weekends of riding sometimes you forget to top off the tank before "lake day." I generally never let the tank be less than 1/4 full. (For me) Usually it a takes a little bit of rpm to get it on plane but once you are on plane I'm able to bring them back down and still be on plane. Especially with two passengers onboard.

 

[kenfyoozed]

Is there any other way to check the oil other than pulling the front storage bin or the idiot light?

 

[mikidymac]

Is there any other way to check the oil other than pulling the front storage bin or the idiot light?

That's the easiest. On some models you can see if after removing the seat but it can be hard to see the actual level.

 

[kenfyoozed]

I stopped and picked up another gallon of oil. I should have picked up 2. I was able to add the entire gallon of oil while watching with the seat off. With a full gallon added it is just now completely full to the top of the tank. The manual says the capacity of the oil tank is 1.6G. When adding the original gallon would it actually take .4G to fill the oil lines to the rotary valves plus the return, feed line to the pump, bleed to pump and then fill injector line? Could all of this actually taken .4G? I'll keep a watch on the oil consumption. I would assume if the injector is feeding to much oil it would smoke excessively and foul the plugs. There is not much smoke, definitely not what I would say is excessive. The plugs are dirty but it not like they are fouled to the point that they won't work.Am I just being overly concerned at this point?