'03 sportsman won't start
 

Alright to make a long story short, I put a 1998 sportsman engine into a 2003 sportsman frame. Now that I've fianlly got everything together, I can't get the engine to fire. It turns over real good with the starter and I'm getting good spark, but it still won't run. I don't think its a fuel issue as I've tried squirting gas right into the carb with no luck. What could I be missing? I haven't checked the compression, but just from pulling the rope it seems to be good. Thanks

this place will help you if its a crab of fuel issue but id be curious about how much comp there actually is buying a tester will suck but be handy forever if you got gas and air and spark i mean you got every thing
Motorcycle Carburetor Theory 101

Are you sure the engine was able to run normally before the install? If not, it could be a lot of things... timing might be a good place to start...