yOU SAID YOU HAVE CHARGED THE BATT!!! Was atv charging ok? may try test voltage regulator this can also effect ignition systems from firing and may sure battery voltage is getting to this part also....

Problem is you can't test the regulator if you can't get it running. Honda 450 regulators play up and kill the spark, but the only way to check them is substitution, if the bike then starts, the old one was faulty.

.If atv regulator not geting 12volts to it Yes it canbe the problem

Also can test diodes in regulator

Thanks. ..battery is brand new. I just put a maintainer on it once in a while. I don't think I have a charging problem. Regulaltoe...not sure. First of all, not to sound to stupid but where is the regulator on a 350 big bear?