Is the 12v battery required for this bike to get spark? 
 

Yes it is. If ya happy to kick start it any smaller 12 will do to run it. Generator should adjust itself back to what battery requires. Quite a big expensive battery the original, to have grunt for the starter part of the generator.

Thanks appreciate it. Been testing this generator and everything has checked out but still wasn't getting spark on my tester. Haven't tested anything outside of that tho. So I have a couple 12v powersport batteries I'll test for spark with a known good battery and go from there.