06-08-2009, 08:35 AM #1
2000 GP1200R bogging low to midrange
My family owns a 2000 Gp1200R that we have had since new. My dad has always taken care of the service of it but its just not running right.
We are having an issue with the ski bogging badly from a dead stop as well as from midrange. It runs good once its high up in the RPMs and I GPSd it yesterday at 58.7.
The engine has been rebuilt I believe two winters ago, not sure if they serviced the carbs when it was done though.
We are going to replace the plugs and see if that works, but I am just looking for any other things to check next weekend.
06-08-2009, 08:46 AM #2
Look into popoff pressure in the carbs.
06-27-2009, 08:15 AM #3
Well I have been doing a fair bit of research and have a good idea of the problem. I believe the carbs just need rebuilt as they have never been touched.
But we replaced the plugs with no change, I did see power valves shafts rotate when you hit the starter button. But it has basically no power until nearly 6,000 rpms then it takes off much better. I am wondering if the power valves are stuck open or have broken or something similar. It does not have the retainers or any preventative deal like that. The ski has nearly 150 hours on it.
I am sort of taking over maintaining the thing because it has not been very well serviced thus far.
I also noticed that the bolts that hold the exhaust to the motor are missing, it seems that one of the studs snapped off in the exhaust portion and the rest was rubbing against the spark plug boot and actually wore a hole in it enough that it will zap you if you touch it (dont ask how I found that out )
I am going to be getting a new set of plug wires and swapping them out. I am going to buy new studs and nuts for the missing ones as stated above. I am going to pull the exhaust out and see if I can get the broken stud out first though.
I am planning on pulling the covers off the power valves this weekend to see if there is any visible damage. I am brining a compression tester with me as well.
Hopefully I can get this nailed down, but any other ideas would be appreciated.
06-27-2009, 06:10 PM #4
Well compression test results
Front Cylinder - 120
Middle Cylinder - 115
Rear Cylinder - 95
That is pretty scary. Makes me wonder if the power valve broke in the rear most cylinder. I will have to pull the thing out of the water to dig deeper into it.
06-27-2009, 08:00 PM #5
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