Calling all jetpump experts

[sledman1]

Calling all jet pump experts. I have a 98 GTX Limited (951cc). When I purchased it and used it for the first time it had a chatter coming from the jet pump only when the jetski was in the water and at idle. No chatter when out of the water or as soon as I give it some gas in the water. I pulled the pump and replaced all the bearings, the driveshaft and the wear ring. The original wear ring was brass and it was scored up. The impeller was dinged up a bit but decided that it was good enough to use and just cleaned it up with a file.

The ski still has the same chatter as before after the pump rebuild. I pulled the nozzle off and inspected the new plastic wear ring and it is scored up. The ski cavitates when you first start off and that has gotten worst with time. The impeller edges facing the front of the ski are now in bad shape. I have not sucked up any rocks since the rebuild, just weeds. I am guessing the cavitations have damaged the thin leading edges of the impeller. Any ideas as to what I missed or did wrong? Thanks so much for your help.

 

[LouDoo]

The chatter you hear is the "SeaDoo Rattle" and is normal until the pump loads up, just over idle. The cavitation could be from various sources. When you replaced the wear ring did you replace the neoprene seal between the pump and the ride plate? Did you use an OEM wear ring? And it could be as you stated from the impeller. Another source for cavitation is a worn carbon seal.

Lou

 

[Dr Honda]

As Lou said... its normal for a seadoo to have a "Knock" in the pump. The reason is... the pump shaft isn't loaded. So... when the pump pressure is low... the shaft kicks back and forth.

 

[sledman1]

This model does not use a neoprene seal. You just use the black RTV. Thanks for the info on the "seadoo rattle". Would of never guess that was normal. Not sure if it is an OEM ring. I just read on another tread about the wear ring being loose. This one was not tight when I installed it. I am not familar with the carbon seal. I will have to look that one up. I am thinking that maybe a loose wear ring is why I already have grooves worn in my new wear ring. After the summer I will pull the pump again and replace the wear ring with an OEM, replace the carbon seal and also put on an aftermarket impeller. Maybe I will end up doing it before then if I get fustrated enough with the cavitation.

 

[sledman1]

Where is the carbon seal located?

 

[sledman1]

Found it. Do you have to pull the pump/ shaft in order to replace the carbon seal?

 

[SabrToothSqrl]

you could pull the pump or the engine, your choice. May I suggest the pump

 

[sledman1]

Thanks. Good advise