Sportster Carb Farts
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Joined: Feb 2006
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From: Alabama
Sportster Carb Farts
Need Help
I have a 99 Sportster 883. I have done a Stage I upgrade myself and am now experiencing carb farts and gas in the air filter. In the dark, you can actually see a flame shoot out of the carb. I have rejetted and experimented with several different jet sizes to no avail. the performance does not seem to be effected with the jet changes and the bike still farts. I'm almost to the point of buying a new carb. but this doesn't make since because a carb is so simple and there has to be some kind of fix.
Any suggestions would be appreciated.
Thanks,
Ray
I have a 99 Sportster 883. I have done a Stage I upgrade myself and am now experiencing carb farts and gas in the air filter. In the dark, you can actually see a flame shoot out of the carb. I have rejetted and experimented with several different jet sizes to no avail. the performance does not seem to be effected with the jet changes and the bike still farts. I'm almost to the point of buying a new carb. but this doesn't make since because a carb is so simple and there has to be some kind of fix.
Any suggestions would be appreciated.
Thanks,
Ray
Road Master
Joined: Aug 2006
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From: Orting, Wa.
RE: Sportster Carb Farts
Blip the throttle a time or two and observe the results. If the motor responds with a gratifying blast without backfiring through the carburetor, you have your idle mixture right. If it backfires through the carburetor ("carburetor farts") you will want to back the idle mixture screw out another 1/4 turn. Do not go too far, as too rich an idle mixture will certainly cause you many headaches and poor gas mileage.
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From: Alabama
RE: Sportster Carb Farts
When you say "blip" the throttle, are you saying to open it quickly a time or two?
Thanks for your response. This is the kind of info. I was looking for and I have a feeling my problem might be related to the idle mixture screw.
Ray
Thanks for your response. This is the kind of info. I was looking for and I have a feeling my problem might be related to the idle mixture screw.
Ray
Road Master
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From: Orting, Wa.
RE: Sportster Carb Farts
ORIGINAL: raym
When you say "blip" the throttle, are you saying to open it quickly a time or two?
Thanks for your response. This is the kind of info. I was looking for and I have a feeling my problem might be related to the idle mixture screw.
Ray
When you say "blip" the throttle, are you saying to open it quickly a time or two?
Thanks for your response. This is the kind of info. I was looking for and I have a feeling my problem might be related to the idle mixture screw.
Ray
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Joined: Jun 2006
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RE: Sportster Carb Farts
I have played with 2 Keihin carbs over the years, following all the advice you find on the internet. What finally cured the farts on my 97 Buell was a Dynojet thunderjet kit. I know people will say they are junk or they don't work or they are a rip off.......But that is what finally fixed my Buell. I found the kit on ebay and it made my bike completely trouble free.
4th Gear
Joined: May 2018
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From: Maybee, Ohio
chronic cough
Yea, mine has got it this year. I have not taken a look at the carb yet, as it was running and I want to ride. I did the yearly stuff oil change (was black as coal but no grit only did 400 miles last year BOO) I would think the oil should not be so dark. Also got the plugs done went with an autolite plug this year vs the japan plug I got last year (they were free from a friend) plugs looked well used but normal to me, changed 'em anyway and checked gap. I took a look at my air cleaner cover and replaced it with a unit that has no hole on the bottom (I had a basket case it came with many parts, it had two ham cans did not know which was correct) there is an air intake on the back side of the air cover it looks to be shaved off flat, it has plastic bristles like some one cut it, did that go closer the the jug to pick up heat? I went to Shell and got a 5 gallon can of their 95-98 (can't remember now) octane gas. I have another station close by that sell 105 racing gas which might be another idea to clean the carb out. My bike does not like Kroger 87 octane that is for sure (unbranded **** gas). Going out for a ride to see if it idles smoother while cold. Once it hits 200 degrees it seems to run fine, it is why I think I will need to clean the gum out. Oh yes and I bought a little oil temp dipstick. It is always good to know how hot this thing is. Last year I got burned by the oil tank once cause it was so hot. I parked it in the shade for an hour, had lunch and it had cooled down. Maybe why the oil burnt up?
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Joined: May 2014
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From: florida
first off, what exhaust do you have on it, second off what size jets are in it and how many turns out is your mixture screw. do you have any intake vacum leaks? leaks need to be confirmed and repaired before diagnosing any carb issue.
one all that is good, a 45 or 42 slow jet with a 160 or 170 main jet should get you in the right area, you also want to confirm that your accelerator pump is working correctly also, look down the throat and twist the wick and see if you see fuel squirting into the throat from the little brass nozzle off to the side.
check on that stuff and report and we ca move on to the next issue,,,,,mind you an 883 with a crappy exhaust system on it (drag pipes) may never tune up correctly.
m
one all that is good, a 45 or 42 slow jet with a 160 or 170 main jet should get you in the right area, you also want to confirm that your accelerator pump is working correctly also, look down the throat and twist the wick and see if you see fuel squirting into the throat from the little brass nozzle off to the side.
check on that stuff and report and we ca move on to the next issue,,,,,mind you an 883 with a crappy exhaust system on it (drag pipes) may never tune up correctly.
m
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