I have a 1998 polaris sportsman 500cc and its lost alot of power. It also pops when it revs high, ive had it ful throttle goin up a small incline and it only goes about 15mph in high gear. Ive checked the carb, the exaust. Nothin seems to work. Anybody please help me

 

Needs a cam shaft.Exhaust lobe will be gone.

 

im not really sure what a lobe is and why do u think it needs that. I think it might have to do with the electronic throttle control??? But you may be right thank you for posting.

 

Adjust the throttle cable.

 

Trust me it needs a new cam shaft,the exhaust lobe on the crank shaft will be the middle one,the lobes are the raised portion on the shaft open the valves on rotation.The center one will be worn down.

 

AS FOR THE POPING IN REVERSE DONT WORRY ABOUT IT ITS JUST LOADING UP CAUSE OF THE REV LIMITER MY SCRAMBLER 500 WILL DO THE SAMETHING. AS FOR LOSS OF POWER LIKE MOODSTER SAID THE CAM MAY BE THE PROBLEM IN CAR ENGINES WHEN THE CAM IS WORN THE CAR WILL PERFORM BADLY.

ALSO ARE U SURE THE BELT IS NOT WORN AND SLIPING MY FRIEND HAD A SIMULAR PROBLEM.

 

Same thing happened to my 99 500. Lack of power, starts popping at higher rpms. The power loss was kinda gradual until it finally would overheat. Went through carb, everything else I could think of hoping it was not the cam. Had a few Polaris mechanics listen to it and the cam is what they said right away. I have heard it is common on them.

 

the belt is not sliping and the popung happens when i go forward not back.

 

It is the cam!

 

It could be the cam or the throttle adjustment. Check the throttle first though.