97 gsx 787 problems

[2012ram1500]

Hey guys im new here but have had seadoo's for years and i need your guys help!!!

so heres the problem i bought a 97 gsx 787 and runs great out of water tachs up to 7200rpm's no problem, as soo as i put it in the water and give it throttle it will rev up to 2460 rpms and if i pull the throttle any more the the rpm's start decrecing and will stall out.

but if i pull the choke out about 1 inch the ski pick ups and gose like a bat out of hell, so it seems that i have a vacume leak some where but the question is where ???

heres what i have done,

- checked compression - 170/180 per cylinder
- rebuilt the carbs 2 times ( there is NO throttle shaft play )
- replaced all ( gray ) fuel line
- replaced fuel selector
- replaced fuel filter o-ring ( the one in front )

Any info would be greatly apreciate Thank You!!:thumbsup:

 

[bigJake]

first place I would check for a vacuum leak is the carb base gaskets. If you spray some carb cleaner around the base of teh carb and it revs up then it is leaking. Also, I would check the compression with a different gauge. Those readings seem too high to be correct.

 

[2012ram1500]

Thanks for the reply, motor was rebuilt with a 5mm over bore from the previous owner, so its a fresh motor, i checked the carb gaskets already gaskets are new and tight no leaks there

 

[Briceybobo]

I am having the same problem on a rebuilt engine. Did you figure out what is causing it? I'm thinking there is a vacuum leak in the the rotary valve.

 

[Seadoobuddy]

I believe that pulling the choke to make run better means that it is running lean.

Like the other have said, check for air leaks even around the fuel line clamps and all gaskets.

Is it 5 MM over or .5? What grade of gas are you using if it's really 180 PSI?

 

[LouDoo]

This thread is just getting too confusing. Briceybobo I would suggest that you start your own thread.

BTW 180psi is way too high for compression, don't run this ski until you get the compression down to a reasonable level.

Lou