2003 Polaris Sportsman 700 twin – won’t start or crank properly

2003 Polaris Sportsman 700 twin - I use this machine exclusively in the winter to push snow. Recently it's been losing power and dying at idle. However, now it won't start and when I turn it over, it will cycle a few times, then clunk and seems to jam. I've replaced battery, solenoid and starter with no improvement. When I opened the air filter box, I found quite a bit of liquid - assuming mostly gas from the carburetor. Probably have a clogged seat and will clean that, but not sure that would cause the new starter to jam like that. I read somewhere that the exhaust has a valve that might be stuck backing up, causing too much back pressure? Any thoughts/help would be great!

2016 outty 450 L

Ravaging through snow until bike would only move slightly in any gear in 2x4 or 4x4? Thought i smoked the belt but after checking its fine? Any ideas?

New ignition switch need programmed?

I recently had my 2011 DS-250 stolen and they stuck a screw driver in the ignition and screwed it up.

I bought a new ignition switch for it. It worked at first but then my check engine light came on and I could not start it any more.

Do I need to take this to a dealer to reprogram something? and do they charge for this? I already feel violated cause this was stolen right out of my backyard.
I don't want any more expense!

Thanks guys,
Gary