Problem With 2001 yamaha Gp800R

[YamahaSpeedster]

Hi my Waverunner has low compression I just got it from a friend for free but before I rode it I checked the compression and it was 90 on the front 122 on the back so I know it has low compression but when I rode it the first minute or so it was boggy and I couldn't get over 7mph but then I shot off and I rode it for an hour or so and I had a Gps speedometer and I maxed out at 54 and after a few minutes of riding it at high RPMs I can be at a stand still and gun it and it takes off like its nobody's buisness. so after that, I took it back and did another comp test and it was way different 120 on the back 118 on the front. So I wanted to know if there's anything I should do or can I just leave it and is 54Mph slow for the Gp800r.

[SBT-Tech 1]

Re: Problem With 2001 yamaha Gp800R

If it was sitting for a while it may have had some carbon build up on the piston rings that frreed up and now compression is back to where it should be. 54 MPH is pretty good for a 800.

[YamahaSpeedster]

Re: Problem With 2001 yamaha Gp800R

what do you mean by cavitation my friend said it could be a piston ring. But I'm at a loss I can try to upload a video of it starting out of the water and while I'm riding it. Thank you for your help so far.

[SBT-Tech 1]

Re: Problem With 2001 yamaha Gp800R

Sounds like cavitation.
Try buying this kit for the jet pump and water intake grate area.
https://www.watercraftsuperstore.net...-Seal-Kit.html

[YamahaSpeedster]

Re: Problem With 2001 yamaha Gp800R

Yah that would make sense but I just got done with about a two-hour ride and I rode it hard but it actually felt boggy at high speeds I maxed out at 45mph on the GPS and the water was glass smooth I couldn't get over 6000 rpm and when i was WOT it was making a wierd sound like it was slipping it sounded like if you are in a car in neutral and you rev it all the way. it was a lot slower and when i went in a turn it would cut the power tremendously and when i straightend back out i got power back.