Replaced wear ring. Still Cavitates

[kalibo]

I have a 1997 GTI that I inherited. I had to replace the engine before I ever got to take it out on the water. After that was taken care of I took it out for the first time and it ran ok but not that great. It was slow off the line and would top out at about 38-40 mph.

After doing some research I figured it was the wear ring. I replaced that and while doing so I noticed a broken hose clamp around the drive shat so I replaced it with a good clamp and took the ski out again. It would not even get up on a plane and was taking on water bad. I found that the carbon ring had slid inside the rubber boot before I replaced the hose clamp, and when I put the new clamp on I didn't catch it,and therefor was not sealing against the metal collar. So I fixed that.

I took it out today and it ran great (50mph) except it still cavitates off the line if I punch the throttle. If I ease onto the throttle It will get up and go but If I punch it it just cavitates and doesnt go to well until I let off and slowly get on the throttle again.

Is there anything else I can check? What would cause cavitation only in this specific way?

 

[LouDoo]

Since you have replaced the wear ring, it's probably the carbon seal, it's inside the bellows that you replaced the clamp. You'll need to pull the pump to replace the carbon seal and rebuild the drive shaft.

Lou

 

[kalibo]

The carbon seal looks good. Is there anything I can do to check the shaft and carbon ring before I spend more $ on it. I don't want to throw another $100+ at it unless I'm some what sure it will solve it. Thanks again, Lou.

 

[LouDoo]

When you replaced the wear ring did you replace the large neoprene washer between the pump and ride plate, or seal that area? If not you could be sucking air.

This is a trick I learned from Dr Honda, put a blob of grease on the carbon seal, if the ski temporarily stops cavitating then the carbon seal needs replacing.

Lou

 

[kalibo]

There was no neoprene washer on mine. That may be the problem right there. I'll check on that and the grease trick sounds like a great idea. You are a wealth of knowledge. Thanks again.

 

[LouDoo]

Thanks for the compliment, but most of what I know I learned from other members of this forum, Seadoosnipe, Dr Honda, Bill, Minnetonka, and many others.

Here's a link to the neoprene seal.

http://www.parkeryamaha.com/seadooneoprenepumpseal293200024.aspx

Lou

 

[kalibo]

Thanks. One last question. On the parts diagram for my 1997 GTI there is no neoprene seal. On the 1996 GTI and the 1997 GTS there is. Would it hurt to use one on the 1997 GTI. A $6 part would be worth the try maybe.

Here is the diagram I'm talking about. It looks like the '96 and '97 had different pumps.
http://www.seadoopartshouse.com/#/Sea-Doo/GTI,_5641,_1997/05-_Propulsion_System_(GTI)/5687/6459

 

[Dr Honda]

I put them in all of the 140mm pumps. Any air leak will cause cavitation... so it helps. Some people like to put a bead of RTV around the pump housing... but I don't, because it makes it hard to take apart later on.

 

[kalibo]

So it WILL work? I'll order one tonight. Thank you both for the quick replies. You guys rock.