Kawasaki klr650 backfiring problems?

I own a 2004 kawasaki klr650, recently it has begun to backfire terribly while riding to the point that it is unsafe to drive. I have maintenanced the carburetor and yet the problem remains making me believe that the problem is in the ignition, but I do not know where to begin looking, or what to replace. Any help

I own a 2004 kawasaki klr650, recently it has begun to backfire terribly while riding to the point that it is unsafe to drive. I have maintenanced the carburetor and yet the problem remains making me believe that the problem is in the ignition, but I do not know where to begin looking, or what to replace. Any help would be appreciated. Thanks.

Also, the problem seemed to arise when I began using 91 octane fuel, but Im sure that is coincidental

Other answer:

Joseph Heimann:
The carburetor has an "air cut valve" to prevent backfiring when decelerating.
If that is when the backfire happens, the air cut valve and ports should be inspected.
# 14025A is the cover for the valve.
http://www.partsfish.com/oemparts/a/kaw/…
The cover has a port as tiny as a pin head.
Spray into it with carb cleaner in a spray can.
If the cleaner comes out the center of the cover, the port is clear.
The carburetor has a port – spray into that – if the spray comes out a different hole, that port is clear.
Make sure the rubber diaphragm moves freely and is not damaged in any way.

Changing gasoline types could free up any stuck on carbon, or increase carbon deposits depending on the quality of gas.
Try installing a new spark plug to see if that clears up the problem.

Candid Chris:
Probably a combo of things going on.
Guessing that you use E-fuel and the bike sits around more than not. The E-fuel causes gunk to collect in the fuel system.
Also guessing that your KLR is designed to use 89 proof.

So you have gunk and put in higher octane which dissolves some of the gunk, that gunk goes to the Pilot and Main jets.
The blockage on the Pilot would make poor idling RPM but a blockage on the Main would cause a shortage of fuel flow making it run leaner, thus the backfiring.

Have read reports of intake vacuum leaks that could also cause a lean mixture.

As said, could be a combo of things but it could be an electrical issue.

Sorry, hard one to guess without being there.

Lipstick Girl:
Do you use a Scottoiler because this can cause these problems when the rubber seal parishes and let's in false air.?
If you don't then it's probably an ignition problem as you say.
Joseph Heimann:
the bike backfires while accelerating rather than decelerating. making me lean towards the electrical problem, i also cleaned and maintenanced the carb so that it is functioning like new, this makes me believe that it is electrical. what would the first solution be if this were the case, other than a new spark plug
james:
yes

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