hello , i have a 1997 Polaris sportsman 500 , and lately its been acting funny , and now it wont start ,.. before it died , it kept dying out when you hit a certain spot on the throttle , but once you got past that it was fine , it also ran hot ... but now it wont start , there's plenty of fuel and spark too . i played around with the carb abit and got it too backfire and sound like it was idling while i was tuning it over with the starter , but it would not sustain its own idle ... i also noticed its shooting fuel up into the air intake when i try too start it and press the throttle . i have another carb from a parts polaris i could put in , but i think its newer , and it seems like alot of work for a problem in not even certain is in the carb .. also hte compression is at about 60 Psi . ... but like i said , when it ran , it ran great

 

Sounds like the common problem of a worn out exhaust cam lobe. 97 model was right in the years of this happening on the Sportsman. 1996-2000 models. Most would idle,backfire if you gave it throttle and spit back into the air box. When they really got worse they wouldn't start. Compression can be false way to tell on this even with a worn cam. Should normally be between 50-90 psi,but all it takes is to pull the cam cover and check if the lobe is the problem. Here's one members pics of his cam that failed. May or may not be the problem. http://forums.atvconnection.com/pola...d-cam-pic.html