1996 GTX wear ring-impeller and carb question

[gpshogan]

Hello all.

I have a 1996 seadoo gtx with a rebuild 787 motor. It runs gd. but will only run about 47 mph. Is this normal for the year? I ave noticed that my plugs are black and a little wet so maybe I need a carb adjustment.

I took off the jet pump to check out my wear ring and impeller. The impeller has little nicks on the blades. Not the blade edge that goes againts the wear ring but the other edge. Very slight nicks. I used a file and cleaned them up. The wear ring just has some scratches, but no gouges, or anything. I measured the clerance between the middle of the impeller edges and the wear ring and its about .30 to .40 mm. Is this ok??? I have noticed that it tighter on one edge than compared to the other. (I measure at different spots ect. 9 oclock, 12 oclock ect. But never more that .40 mm. But it def had a little fluxuation. Is this ok? Also can I use black silicone to seal the pump to the housing when I put it back on the ski? any suggestions on the back wet plugs. I just had the carbs rebuilt by a reputable seadoo dealer. Also, I was going to change the pump oil while I had it out. Can I just take off the alen key bolt, drain it, and fill it back up again on my work bench? How much do I put in, or do I fill it to the top.

Thanks for any help you guys can give me.

 

[seadoosnipe]

Plugs...

It sounds like you may be a little rich, but before you make an adjustment, I suggest you take it out, run WOT for about 15 minutes, then kill power. Do not come back to idle, just kill the power. If they are still black and sooty, then you may re-adjust your mixture.

You can use 100% silicine to seal the pump housing.

You mayhave a problem with your bearings if your clearance is different from one side to the other. Grab the impellor and try to move it side to side. If there is some slop in it, may be time for a bearing job.

Oil change. Yes, pull the plug on the cap, or better yet, if you have the pump off, take out the 3 bolts and remove the cap. This way, you can drain it faster and ave a tiny look at the shaft. you won't see a lot. Biggest thing you want to do is look at that oil for signs of water. It will be a bit milky in color. There is an "0" ring seal in that cap and a small spring with a small metal plate, holding tension on the impeller shaft. With everything real clean, you can dab a bit of grease on the cap to let it slide in gently.

Fill the pump housing back up to the edge of the hole. But if you emptied it all out, keep it open till it quits draining into the pump housing.

Use Seadoo synthetic pump oil.

 

[gpshogan]

I checked the impeller for play. Nothing at all side to side. What else could it be? I just dont know why the clerances are different at different places. One side measures .25mm and the other about .40mm. Are these clerances in spec?

Whats the best way to make my carb mixture a little leaner?

Is 47-48 mph normal WOT for a 1996 800cc 110 hp gtx?

Thanks for your time.

 

[kustomkarl]

Wear Ring clearance for your seadoo 1.0 mm or (.040in) Measure the clearance at the center of the impeller blades, with a 12” long guage. Measure the clearance from the venturi side of the jet pump. I think 47-48 is about correct for that size engine. How is the compression? The compression ideally should be at 150 psi per cylinder. This could influence the color of the plugs and top speed if compression is low.
I hope this helps you.

Karl

 

[gpshogan]

RE:

The entire motor was just rebuilt by a seadoo dealer and the compression is 180 psi at each cylinder. I modified the head a little.