I'm new to this forum, so I hope this works out and can get some help. I'm working on my buddies 2000 Polaris Sportsman 500, as it starts missing on acceleration. His machine was working OK, when on one trip to his hunting stand it started missing. It will start OK and idle without a problem. It has a new plug and I've gone through the carb and it looks respectably clean. I've adjusted the throttle cable (per the suggestion of the local Polaris service tech). I've seen some posts about the reverse rev limiter, but I'm not familiar with that, or where it actually is, so I can't determine if that may be the source of the problem. I'm not an ATV expert, but I am pretty mechanically adept (which is why I agreed to look at it for him), any help would be greatly appreciated. Thanks in advance.

 

Welcome to the forum! If you are certain that the carb is clean, fresh plug, has clean fuel,etc you might check out the cam for any excessive wear on the exhaust lobe. This could cause a good idle,but upon acceleration would stumble,some times backfire (if worn badly). This was a problem with soft cams from 1996-2000 model Sportsman 500s.If center exhaust lobe is not elliptical like the intake lobes at each end of the cam,could be the problem. If cam checks out make sure valves are set at.006 intake and exhaust. OPT

 

OPT... thanks for the reply and information. Seeing that this problem occurred so abruptly, I was hoping it wasn't something as serious as the cam. I will attempt to check this out and review the situation with my buddy. Thanks again.

 

I believe the limiter is incorporated into the speedo on the 2000 models and doesn't have the physical reverse module that could be disconnected like in previous years.98 was last year on separate limiter module. OPT