97 GSX problem getting to full power

[krawler]

97 GSX 787 has issues getting to full power
Hi Everybody,

I've been slowly working my way through the lack of power troubleshooting section of the service manual, but nothing so far is working and maybe someone here has had a similar experience.

The machine has good compression, freshly rebuilt carbs, new fuel lines, new ignition coil, rotary valve appears to be in good shape, rave valves were just replaced too. Spark plugs are the textbook brown color of proper combustion.. There was some water damage in the rear electrical box, the so i replaced the connectors going to the coil as well.

So, on the trailer, the machine revs right up to 7000+ rpm, no problem, however, drop it in the lake and it struggles upto 4000 rpm, and then some times, picks up power again and takes off to full power, also on the lake when i go off a wave and get air under the hull the doo takes off no problem and achieves full power and top speed.


Any one have any ideas?

Thanks a bunch!

 

[GA jet skier]

Re: 97 GSX problem getting to full power

Had trouble like this before, although the carbs had been reworked, they forgot to check the little filter or screen inside each carb. Looks like a mini fuel line filter. Was completely stopped up. You can clean these with carb cleaner and put back in, without having to get new ones, provided they are not damaged. Maybe this helps.

 

[dannyual767]

Re: 97 GSX problem getting to full power

I agree with GA. It sounds like your ski is starving for fuel. The engine revs easily when the pump is unloaded (on the trailer or catching air) but when its in the water, the pump is under load. This load requires more fuel to the engine to be able to achieve WOT. Check those filters.

 

[buzzman]

Re: 97 GSX problem getting to full power

if compression is not around or above 130 rebuild