do you have spark? one thing to check.......I've done this a million times on sleds, atvs, and motorcycles.....make sure both the key and the kill switch are on..lost track of how many times ive tried to start a sled or atv with the damn switch pushed in....... I see you said your plugs looked wet, the 600xcr I just bought did the same thing to me, after sitting a few days it would not start, checked the plugs, wet, dried them out and it would catch but not start, I ended up holding the throttle wide open and it took off, could be your float level is too high, and you are flooding out the plugs, you may need to pull the carbs again and check the levels,and make sure the needle and seats are sealing good to keep excess gas from flooding your motor.
2000 Indy 500 XC, Fox shocks up front, M10 trail in back. '99 440 XCR for my son. 96 XCR 600 SP tripple pipe, 862 miles on it !! (until it snows....then look out, odometer !!)