I have a '03 500 HO with issues. Starts fine, idles perfect, but when moving it wants to sputter and has no power. Will travel at 5 mph if you do not operate the throttle more than a tiny bit. Once you open up the throttle the issues start. Has new plug, gas filter and I have opened up the carb for inspection. does anyone have any ideas? thanks, Tony

 

Have you inspected the cam or checked the valve lash/timing,I know the pre HO engines are more prone to wiping the exhaust lobe but it can still happen due to lack of proper oil changes.It's pretty simple to check if you need detailed help feel free to ask.Welcome to ATV Connection!!!!

 

I hope it's not that serious. Low miles with multiple oil changes... It sounds like when you go in reverse without pushing the reverse limiter button.

 

Lets hope not but it is common in the 500 models, what you just mentioned about the limiter sounds like it's CDI related or in the firing.Maybe some of the others have some advice on that