My Boss has a 92 Polaris 2 stroke 350.. He generally has to replace the plugs every 8 hours of riding because the plugs foul out. Pulled the carb & the main jet is a #30 & he rides around 8000 ft.. is this jet to big?? Any other thing that needs to be looked at??

 

Look at his fouled plugs. Are they black and oily or white?

 

yea, black & oily...

 

What main jet is he running?? The factory calls for a #200 at that altitude he should be running around a #180 to a #185. Since it is a #30 pilot, he could probably do ok with a #25, but try turning the airscrew out first, (ccw) and see if that helps, if you have to go beyond 2.5 turns out from a light seat, then yes he needs to go to a #25. Also, if he is running the stock clutch set-up, he could gain some performance by dropping the weight size down one to keep the RPM's up at the high altitude. I would also recommend checking the oil pump settings and make sure the marks are in alignment and that the choke cable is adjusted properly.

 

A COUPLE IDEAS. HAVE YOU REMOVED PLUGS AND PERGED THE EXHAUST? MUD IN END CAP? OIL PUMP ADJ.PROPERLY?

 

ONE NICE THING ABOUT THE OLD 350L MOTORS IS YOU CAN BORE THEM TO 400CC WHEN WORE OUT. JUST CHANGE MAIN JET AND YOU HAVE A SCRAMBLER MOTOR

 

and you really dont need caps to say that. its like your yelling it.