I have a 2001 polaris trailblazer it got bored it worked fine the chain broke got a new one put it on 2weeks later didn't start I cleaned the carb got new spark plug it gets great spark ,great compression. A year later put starting fluid in it and new gass and it started up ran fine. The next day it didn't start didn't even want to start so I got a new spark plug the carbs clean and still great spark.

I can't think of what it could be

 

Don't just try to clean a carb,rebuild one. Not worth having to go back into one. Probably needs one if it's been sitting up with untreated fuel,plus if it doesn't solve the problem,you can eliminate carb and fuel supply as the problem and move on to something else such as distorted leaking crank seals that could keep it from running right also.http://www.ebay.com/itm/CARB-REPAIR-REBUILD-KIT-POLARIS-TRAIL-BLAZER-TRAILBLAZER-250-96-97-98-99-00-01-/370643954578?pt=Motors_ATV_Parts_Accessories&hash=item564c19eb92&vxp=mtr

 

Thanks I'll try that I took the exhaust of yesterday and it was filled with gas. So I'll try the rebuild