Currently trying to get a 1998 Honda Foreman 450es to run. Last time it was out was probably 3 years ago and it ran fine sold it to my father and there it sat with a dead battery. I put a new battery in it and it would turn over but wouldn’t start. Pulled plug and grounded it to head..nice blue spark. Cleaned carb multiple times, purchased new carb still nothing. Fuses all checked good. Then put a new cdi and voltage regulator and spark plug in and same thing. It sounds like it wants to start (hits periodically) and back fires after cranking awhile. I then pulled the valve cover off to check clearance at TDC and noted the intake lash was waaaaay off. I readjusted it to .006 for both intake and exhaust and still it will not start. I am baffled. I have fixed many ATVs and I have never had this much trouble. The topend was rebuilt less than 100 hours ago.. it has strong compression..blows finger off spark plug hole..getting gas…getting spark. The kill switch is in correct position although could it still cause a no start if its bad? I have heard of bypassing it but I am not sure how. I’m at a loss here and would greatly appreciate any advice offered.

Thanks in advance,

CJK