Personal Water Craft Forum banner

1 - 2 of 2 Posts

·
Registered
Joined
·
4 Posts
Discussion Starter #1 (Edited)
I am new to jet ski's and recently purchased a 2002 GP1200R. It has never run right yet. Here is the story. I bought it in Nov last year. Hit 68 mph on on near smooth water. Then it started running rough. Sounded like spark plugs were fouled. Anyway I winterized and stored in my garage till June. replaced the Cat with a D-plate and switch. took it out and ran okay at first but as it warmed up started running rough again. Took it home found the fuel line on top of the tank came off.(the one with the check valve). Anyway replaced the spark plugs and secured the line and again to the water. Little rough at idle then took off like a dream. At 51 mph she just shut down requiring a tow. It would bump here and there but would not start again. Just got it home. Compression across the board is just 90 psi. popped the power valve covers and all are intact. None have dropped. I just wanting to know if something simple could cause the compression to be this low all together other than rings or the heads. I am an aircraft mechanic full time I am just needing direction with this small engine. I have learned alot recently and need any info anyone is willing to provide. My thoughts are to replace the pistons, rigs and heads as well as upgrade the power valves. By next year I was going to install a stage 2 kit but if need be I can start now. Help please and Thank You very much in advance.

107 hours on the ski. all apears to be stock.
 

·
Registered
Joined
·
114 Posts
you are having typical Yamaha problems!! pull the heads off to insure you have not not damaged the piston or cylinders. Im not really concerned about compression numbers right now, I want a visual inspection and good digital pictures if possible! I also would assume you have fresh carbs and kits in them, think past the upgrade kit for now lets get the ski back to factory performance first! you can E-Mail me at [email protected] with any pics or personal messages, I am limited to this site this time of year, I am a full time Pwc-Cycle tech with little x-tra time! Thank You!
 
1 - 2 of 2 Posts
Top