I have a bayou 220 that will not start. Here is so far. Timing is dead on according to marks, carb is getting gas, plug is firing good crisp blue spark, but it will not hit even squirting gas directly in cylinder. motor turns over fine, compression will blow finger off of spark plug hole. have not checked setting on valves yet, but verified they are working. was riding it and it ran great. parked it to eat dinner, went back out and it would crank but no start. getting fuel, and fire and air but wont even cough. any ideas?