Thread: interestin gp800 problem.....
08-18-2007, 03:55 PM #1
interestin gp800 problem.....
ok i took my gp800 out for the first time this season today. so its been a yr. since i used it last. i replaced the battery tried starting it gas is bad... so i drained the gas, new plugs, put carb cleaner in the gas.. takes a little while to get it going since theres no fuel in it ok no problem... little starting fluid fires right up bogs then runs fine, did a compression check 136 in the front 121 in the back (i thought stock was 120). i rebuilt the motor last april with sbt stock boreable replacement cylinders (i didnt know any better then) on land it fires right up revs right up to 7500ish runs mint. get on the water fires right up revs up great, bottom is a little off mid is ok then it max's out at 6900-7000. and im only doing in the high 40's. and if im on full throttle for a little while every minute or 2 it bogs down then comes right back....it has a new impros impeller on there that was put on right before its final ride of last season and last season it has hitting high 50's maybe even 60..... now theres the whole story where do i start? same thing happened with my gp1200 last yr it was a pulse line EDIT:its not the pulse line in this case i just checked it oh well. im open to suggestions
Last edited by spyder3000gtvr4; 08-18-2007 at 04:28 PM. Reason: not the problem
08-19-2007, 09:12 AM #2
08-19-2007, 10:15 AM #3
- Join Date
- Jan 2006
- Texas City, Texas
Certainly sounds like a carburetor problem to me as well.
I am kind of curious though about your compression. Did you have 120 compression on both cylinders after your rebuild, or was it about 135? In other words, is the 120 unusually low or the 135 unusually high?
I had a problem somewhat like yours with about the same symptoms 3 weeks ago on my 1200R. The compression was about 149-163-150, and I am supposed to see 150 on all three cylinders. Turns out the high pressure on cylinder #2 was from a broken valve. I lost 180 RPMS, ran sluggish from top to bottom, but every now and the boat would wake up. Fortunately, it was a gas valve that broke and the shoulder on the valve shaft prevented the valve from trashing the piston and cylinder.
Check your cylinder compression again.
If 120 is low.... perhaps a trashed piston due to a lean seize (carb problems)
If 135 is high... perhaps a bad valve.
Hope I'm not confusing the issue, but it is something to think about.
08-19-2007, 01:56 PM #4
ok im going to take a look at the carbs, i guess running the bad gas through it at first probably screwed it up. i also did the compression check before actually running the ski yesterday and tested it when i get home it was the same before and after. kinda figured it was something little
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