I have an old 2 stroke polaris xplorer 300 that i can't get running right. It used to run great a few weeks ago. Then the starter went bad, so it sat for a week until i got the new starter in. I had to remove the beltcase and also the flywheel on the other side of the motor, so that I could get the new starter motor and gear in. Then I put everything back together, and it doesnt want to fire up. I looked in the carb, and the jets are clean and everything. Sometimes you can get it to run if you hold the throttle wide open and start it, but it barely revs like its bogging real bad. Then if you slightly let off the throttle it immediately dies. I tried adjusting the air screw but that didn't help. I dont know what couldve changed for it to do this. Also if you spray carb cleaner into the intake, it revs up quite a bit.