I rebuilt the top end, cyl honed, new pistons, small end bearings,wrist pins.
its got a Protec Head & Expansion chamber, Riva Exhost, prop and nosel, jetted.

compression is around 180 185. all the electrical looks minty mint opened the CDI box it looks factory fresh in there.

i'll be ridding perfect with tons of power for about 30 min or so all of a sudden she dies as if u hit the stop button to kill the spark. i will restart it and she will only let me give it a lil throttle untill.... i guess it cools down. n runs perfect again.

ive checked for proper water flow thru head/exhost also removed temp sensor out of head.


I needa talk to some1 that is a yamaha jetski Guru! whea you @ HOmiE!?

 

If it weren't for that god awful pipe I'd suggest pulling the head and checking for scoring. It definitely sounds like you are describing and over-heating problem.

 

like i said above i just got the cyl board out with new pistons/rings bearings im thinking maby the temp sensor is screwy and it thinks it overheating.. i jus replaced temp sensor have yet to try her out. cause b4 it starts acting up the thing runs mint mint i was lovin it lol

 

Sorry, I misread. I thought you had disconnected the sensor all together (something I do w/ all my motors).

 

yea ive heard most ppl do take thos out they cause problems but i was kinda paranoid that i dident hook up all the exhost / cyl head hoses correctly so i dident want to do that just yet (im a motorcycle tech i really know nothing about jet skis' yet) I should b brining her home from upstate this week hopefully i'll have some back flip footage LoL

 

boy this section of stuntlife is POPN! (joke)

so im puttin the ski in the water 2moro im hopin for sucess i'll let every1 that isent lookin @ this thread kno how it went :YEAH

 

How'd it go?

 

heard it was cold

 

BOY WAS IT COLD!!! lol but we toughed it out,
iite so finally its done.... since the ski came with After market head/exhost/carb space plate/intake, it was running way to lean on full throttle and seizing. so ive been playin with the jetting i went from a stock 130 main jet to a 140 (still seized) then to a 150 and finnaly its starting work better and better i have a feeling im even gona have to go a 160 main jet and go back to stock on the pilot jet b/c im fauling plugs on the long 5MPH canal ride.

2day i actually go to ride and wow this thing is a **** load of fun toped out @ almost 50mph, handles Crazy, and jumps outa the water on chop alone lol SICK!

so yea too lean = seized piston(s) TWO STROKE!