I recently purchased thru private sale a Sportsman 500 HO 2005 ,model carbed. My problem? It quits when you have the throttle about half open. Put a spark test inline and it's just like somebody turned the key off. You can start right back up, but will quit as soon as the throttle is roughly half open. Replaced the ecm was told this would take care of the problem, but it hasn't. What else do I need to do? Are the coil and CDI box at fault? I priced them thru my local Polaris dealer, thought farm equipment parts were high. Any suggestions? My first Polaris, really thinking of fixing up my Honda Foreman.

 

Not sure if it's your issue, but take a look at the throttle safety switch. Something easy to rule out anyways.

 

I have looked at it, but I will check it again. Seems like you move the throttle that is when the spark will die.