Ok first off , Hello everyone! Heres my predicament with my sportsman 700 efi . Bought it new in 07 ,my buddy bought one first gonna ride on his moms farm and use them for hunting, long story short he got divorced sold his quad and vanished. I rode it a little but only have 35 miles , yes only 35. Well that led to it sitting and me not having time ,kids, gonna start using it again this summer , put in a new battery started it up . A little tough to start. It was running had hesitation when throttling up. Ran some sea foam and fresh gas kept getting better. Started good hesitation gone , then yesterday wouldn't start, popping and backfiring and ran diagnosis have a code 21. From reading sounds like it could be many things , just need a place to start I'm not familiar with working on atv only cars motorcycles and small engines any help would be appreciated
Thanks
Thanks