Running rich
Tourer
Joined: Jul 2010
Posts: 465
Likes: 0
From: Vancouver Washington
I have the same problem , new pipes, running rich leaned it out , but if use my choke to start the bike it will turn my plugs black , New jets I think are need or the choke is not opening all the way . I went to a shorter pipe less back pressure, If you find the answer let me know I'll try it
Cruiser
Joined: Jul 2011
Posts: 210
Likes: 1
From: Pacific Northwest
I think you aren't 'getting' what people are telling you. First of all, pipes turning gold isn't an indication of anything except low quality chrome.
You say you "leaned it until it backfired", but lean condition does not cause backfiring through the exhaust. Lean condition causes popping through the carb; rich condition causes backfiring. It sounds like you're turning the idle fuel/air mixture screw the wrong direction and doing the opposite of what you are attempting to do.
You said had the carb tuned for new pipes, but do you have a high flow intake? If not then stage 1 jetting would be too rich for a stock air cleaner.
You don't know how to tell what size jets you have? there is a number stamped right on them. You have to pull the pilot jet to read the number, but you can read the number on the main jet as soon as you pull the float bowl.
Elevation shouldn't be an issue at all unless you go above 2500-3000 ft, and even at that it would only run slightly richer than it does at sea level. Elevation won't cause significant rich running issues unless you get above 5000-6000 ft.
You say you "leaned it until it backfired", but lean condition does not cause backfiring through the exhaust. Lean condition causes popping through the carb; rich condition causes backfiring. It sounds like you're turning the idle fuel/air mixture screw the wrong direction and doing the opposite of what you are attempting to do.
You said had the carb tuned for new pipes, but do you have a high flow intake? If not then stage 1 jetting would be too rich for a stock air cleaner.
You don't know how to tell what size jets you have? there is a number stamped right on them. You have to pull the pilot jet to read the number, but you can read the number on the main jet as soon as you pull the float bowl.
Elevation shouldn't be an issue at all unless you go above 2500-3000 ft, and even at that it would only run slightly richer than it does at sea level. Elevation won't cause significant rich running issues unless you get above 5000-6000 ft.
Last edited by pnw_hd_rider; Oct 29, 2011 at 01:45 PM.
Cruiser
Joined: Oct 2011
Posts: 178
Likes: 0
From: SE Florida
jaredb, sounds to me like you are trying to tune the carb with the idle mixture screw...
If you are only referring to the idle mixture, I apologize.
When you say backfire, do you mean through the carb, or through the exhaust? If you're not sure, take the air cleaner cover off and keep your face away from the carb...Under what condition are you experiencing the backfire, when stationary and cracking the throttle, or while riding?
Have you checked your accelerator pump operation?
Edited to add that if you are not sure of what you are doing with a carb, and are making changes to intake/exhaust/cam systems, look around for a good dyno tuner with A/F ratio monitoring equipment. It doesn't have to cost a fortune, many dyno tuners will do a carbureted bike for under $100, if the carb doesn't need major work. It's worth it.
If you are only referring to the idle mixture, I apologize.
When you say backfire, do you mean through the carb, or through the exhaust? If you're not sure, take the air cleaner cover off and keep your face away from the carb...Under what condition are you experiencing the backfire, when stationary and cracking the throttle, or while riding?
Have you checked your accelerator pump operation?
Edited to add that if you are not sure of what you are doing with a carb, and are making changes to intake/exhaust/cam systems, look around for a good dyno tuner with A/F ratio monitoring equipment. It doesn't have to cost a fortune, many dyno tuners will do a carbureted bike for under $100, if the carb doesn't need major work. It's worth it.
Last edited by Panshovevo; Oct 29, 2011 at 10:34 AM. Reason: More info
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