I just got this bike from a repo place. The battery was dead dead! Charged it up for a bit. Started right up. Idle nice. Sound nice. Rev'd it a little. Good. Started revving it about 6-7 grand. Backfires and spots flame and wants to shut off?? Any idea what it could be? Coils? Plugs bad? Thanks!

 

If it's been sitting a while I'd start by flushing the gas tank, cleaning the carbs thoroughly and going back in with fresh gas. My guess is dirty carbs but you don't want to go back and feed them with contamination.

Of course a full basic tuneup should be a given on a 20 year old bike with no service history.

 

That'd be my guess too.

More specifically, it sounds like you might have a sticky needle float valve. Bowls are full of gas, you've started it up, and right about the time the valve should have opened and let more fuel into the bowl, it didn't and you ran out of fuel. When the fuel levels are not correct in the bowl, it'll do weird things to your A/F mixture and it can cause some backfiring before you actually go into full on fuel starvation.

Gas nowadays (with the ethanol) can easily gum up a float valve and cause it to stick.

 

I'd also make sure it was properly warmed up before rev'ing it too much. But the best advice is ...

.... because you're assuming that all is OK otherwise. So, new air filter, check/clean plugs (or replace), fuel as above, oil/filter etc etc.

Dave

 

Sea foam. .
That's my favorite fix for any bike that's been sitting. .
Run it through at full strength. I think it's like a half bottle to a full tank of gas. . And just start it up and let idol, also disconnect your front headlights if your not riding her and burning up the gas while in the driveway, these bikes are notoriously known for their weak charging systems. . I'm telling you this just to be on the safe side.. especially if the bike had been sitting along time. .

 

u know the more i think about it..
you probably have started to take everything apart but if u havnt..i personally have a few older blades and two winters ago on my 96 i had a similar problem, turned ouut that a mouse decided to neest in the airbox for the winter..and litererlly when i opened up the airfilter box there was chewed up paperand hair and almost just like a bird was there.. anyway.. take it all apart.. check everything out.. u should anyway..