Won't start

[HypeDOG]

It's an 82 Yamaha 650 Seca.

Started fine the last time, now won't fire up. Choke on, full, halfway, nothing. I tried for several minutes, finally gave up a a backfire. I've heard backfires before, but that one was scary. Man that was loud.

It did this for the first time Sunday evening. SO I thought, maybe I flooded it. Tried it again this morning, still won't start.

So motorcycle gurus and experts, what do you guys think? Does it sound like a fuel or a spark issue? Where should I begin?

[HandGrenadeKid]

I did the EXACT same thing about a week or two ago with my 81 550 Maxim. The backfire really fouled up my sparkplugs. I popped some fresh ones in there, and it started up perfectly without any choke. Try changin yours out too.

[HypeDOG]

Hey thanks for the advice. I'll do just that.