idle backfire

[muck]

This bike was backfiring when i let off the throttle last week with a unstady idle. it was boncing about 1000 rpms. I ended up changing the vaccum lines and now my idle doesnt jump much at all (very little like 200-300 rpms) But now its backfiring at idle. i put some seafoam in just cause i was planning on making sure there was no gunk in there. but does any one have any ideas here?

[DayKat]

Spark plugs? One mis-firing or all burnt causing unburned fuel to backfire?
Simple but plausible...

[muck]

could be, I checked the plugs last weekend. 1 and 4 had carbon on them. 2 and 3 were clean.

[kevin2502000]

Mine will sometimes rough idle and this is all I do to fix it.... BEAT the HELL out of it for a few minutes, run to redline and let off snapping it back and forth.....works every time for me

[muck]

Mine will sometimes rough idle and this is all I do to fix it.... BEAT the HELL out of it for a few minutes, run to redline and let off snapping it back and forth.....works every time for me

ummmm i pass on that method

[kevin2502000]

seriously, it works. Flushes the carbs out and its fun!

[arsenic]

This bike was backfiring when i let off the throttle

That's not a backfire, it's an after fire, it's caused by a lean condition.

BEAT the HELL out of it for a few minutes, run to redline and let off snapping it back and forth.

thats the dumbest thing I've heard today. Granted it works. It does the same damn thing Seafoam does, without beating the hell out of anything.

[muck]

That's not a backfire, it's an after fire, it's caused by a lean condition.
.

what about the back fire on the idle is that an after fire too?

[bubba600]

"backfire"

Yes, backfires come from the carbs, afterfires come from the pipes. P.S. your avatar gives me nightmares.

[kevin2502000]

I still stand by my beat the hell out of it, carbon kills.................. and its fun!