Miss/Backfire Problem
Thread Starter
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2nd Gear
Joined: May 2006
Posts: 6
Likes: 0
From: Las Vegas, NV
Miss/Backfire Problem
I have a 2004 carbureted softail with a Stage 1 system, 4200 miles with a miss/backfire after warm-up. This backfire is intermittent and loud. I have checked jetting, checked for intake manifold leaks, replaced exhaust gaskets, plugs and intake manifold seals. The backfire reminds me of a quick flick of the kill switch. Short hesitation then backfires. I have cleaned the ignition switch and checked the kill switch itself. I cannot seem to get rid of this backfire. Any ideas guys? Also, any freelance HD mechanics in the Las Vegas area? Thanks!
6th Gear
Joined: Feb 2006
Posts: 10
Likes: 0
RE: Miss/Backfire Problem
The stage 1 kit helped, but didn't cure it. It occurs after warm up like yours, but seems to be random - I can drive for several miles and it's fine, then it might do it a couple of times. Mine also seems to happen at within a very narrow rpm range... I'm guessing 2k (whatever 40mph in 4th works out to be). If I drive with the choke partially on it doesn't happen.
Thread Starter
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2nd Gear
Joined: May 2006
Posts: 6
Likes: 0
From: Las Vegas, NV
RE: Miss/Backfire Problem
It sure sounds like the same problem! I have not ridden with the choke partially out but I don't think mine is fuel related. I have gone through the carb with a fine-tooth comb! What is your backfire like? Does it hessitate then backfire? Did you replace your plug wires?
Is there any Master Mechanics here that can help Troll and I with this?
Is there any Master Mechanics here that can help Troll and I with this?
Thread Starter
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2nd Gear
Joined: May 2006
Posts: 6
Likes: 0
From: Las Vegas, NV
RE: Miss/Backfire Problem
Tripl8,
Stock carb and I have gone through it with jets, needle and everything else I can think of! I have done the plug check and I seem to be right on the money. I have replaced the intake manifold seals and carb boot. I do not have an intake leak. I have the air mixture screw out 2 turns right now and have tried many settings. Like Troll, it is intermittant and can go for miles before it backfires again. Sometimes with little throttle movement, sometimes with none.
What gives guys?
Stock carb and I have gone through it with jets, needle and everything else I can think of! I have done the plug check and I seem to be right on the money. I have replaced the intake manifold seals and carb boot. I do not have an intake leak. I have the air mixture screw out 2 turns right now and have tried many settings. Like Troll, it is intermittant and can go for miles before it backfires again. Sometimes with little throttle movement, sometimes with none.
What gives guys?
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Road Captain
Joined: Oct 2005
Posts: 564
Likes: 1
From: Lynnwood WA.
RE: Miss/Backfire Problem
Then my moneys on an intermittant ignition short...findng it might be a bitch tho.
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6th Gear
Joined: Feb 2006
Posts: 10
Likes: 0
RE: Miss/Backfire Problem
Other than a stage 1 kit, my carb is stock as well. In my case I'm leaning towards an air/fuel mixture problem rather than spark/ignition because I don't have any problems if I run with the choke on 1/3. Anyone know how many rpms the engine is turning at 40mph in 4th gear? More importantly, which jet is most important for the air/fuel mixture at this rpm/load/throttle position (cruising steady on flat road)?