lean or rich?

[farmboy1]

Went road riding last friday night with my buddie. He has a 400ex also and toasted him constantly all night long. I think my quad is jetted about right as it runs strong and does not bog down in a taller gear going up a hill. We was running almost wide open, i passed him and let out just because, and he said there was a flame shot out of my exhaust.
so my question is is this good or bad?
My guess would me that i'm running a little rich but not thinking real rich.
once again i'm new to all this and was just stating my curiosity again.
Thanks

[farmboy1]

ttt

[farmboy1]

anyone?

[jcs003]

a backfire is usually a lean condition. more commonly it is related to ignition timing.

[krt400ex]

it could be a couple of things. honestly, rich or lean. generally a backfire is lean though. if you arent running a spark arrestor then i wouldnt worry about it. i had a 400 with full yosh system and no spark arrestor, and it was jetted a hair on the rich side, and you could see a blue flame every so often out of the tail pipe, but only in the dark. i wouldnt worry about it. if it does it constantly and makes a loud pop or bang, then jet it a bit richer