I have a 2002 sportsman 400. Can't hit the throttle hard at all or it will stall and may even backfire. I can rev it up but i have to ease into it slowly. I just put a new cam in it (valves are set @ .006)and I've been through the carb and checked the boots on both ends of the carb with starting fluid while it was running. It drove it one day and at my lake house when I got it home that evening I could hardly get it off the trailer to my garage.
Please help.

 

Unless you have the cam timing off,I'd look at this fuel section from the manual and see if the problem may still be carb related.Not being able to take throttle could be fuel/carb related if you're sure on the cam timing.https://www.google.com/url?sa=t&rct=...U2gGlaHJWSIlbA

 

I just went through the carb and nothing changed. Is there something that I'm overlooking?

 

Simple things like is the air box and filter hooked up? If not it will run lean and bog,sometimes back fire.Plus check for any bare spots on the coil wire.Also unless it was backfiring before the cam swap,I'd recheck cam timing. If cam timing is spot on,certain the carb and fuel supply is ok,problem could be an electrical break down. This is where the manual trouble shooting checks come into play along with stator resistance specs.In case you don't have a service manual.2002 Polaris Sportsman 400 Service Manual PDF Download