Comments on: Why Does My Harley Backfire?

By: Rev. Os.

Rev. Os. — Sun, 08 Feb 2009 07:48:18 +0000

Ok here is the correct answer, and rest assured that this will not be expensive. I had this exact same problem just weeks ago on my old shovel head.I tried everything, new plugs, wires, carb intake boots, timing, lifter adjustment, and it still did this only when i reved it up. it idled fine.Your jets are fine if it ran good before so don’t listen to all the garb.Here is the answer bro believe it or not I am 90 % sure it is your key switch. It don’t get enough power to the coil because they go bad from vibration. Here is how to check, run a jumper wire from the hot battery post to your coil and see how it runs then. If it runs good then, replace your switch they are 23 dollars. Do also let me know what you find, I’m at

By: xjr1300

xjr1300 — Wed, 04 Feb 2009 21:11:53 +0000

ive got no idea, but when you find out let me know, maybe i can get my yamaha to do it

By: Skulls

Skulls — Mon, 02 Feb 2009 07:30:02 +0000

You did say type or year, efi or carb, soanyway if you get to much excess fuel or oil in your exhaust the heat from the pipe will cause cookoff and inite causing a flame, causes: jetting,blowby,or evensticking valve,normally on a H-D if you have drags and are a little rich it blow it out and not pop or flash till you let off, burning what is left

By: Bad Mother Clucker

Bad Mother Clucker — Sun, 01 Feb 2009 01:25:50 +0000

Good lord, adjust or rejet your carb, your running way too rich.

By: REDNECK HOG

REDNECK HOG — Thu, 29 Jan 2009 00:55:08 +0000

PROBALY RUNNING RICH AS YOU HAVE BEEN TOLD .BUT DONT LISTEN TO JEFFYB HE PROBALY RIDES A JAP CAN.

By: JeffyB

JeffyB — Wed, 28 Jan 2009 01:48:09 +0000

50 yr old engine technology

By: Clint M

Clint M — Sat, 24 Jan 2009 17:54:36 +0000

Cool.

It could be an ignition timing issue, running a bit rich, or even a valve timing issue created by a littel bit of exhaust valve overlap.

Most likely just running a little rich. No real problem with that and can be adjusted to lean it out. Don’t go too far though. Rich is okay, too lean can be catastrophic.

Besides people pay good money for flame thrower kits. They’re cool at night.

By: James B

James B — Thu, 22 Jan 2009 19:53:33 +0000

Burning to rich