88 883 - initial acceleration sputter
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Road Captain
Joined: Apr 2010
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From: Texas
88 883 - initial acceleration sputter
On my sporty, when taking off from a stop sign/traffic light, it will cough or sputter (no popping) pretty much all of the time. Idles fine and when I jump on it runs very well.
My thoughts are that my middle jet is wrong - this is a 96 carb (can't remember the jetting). Right now it has the stock air filter (which means very little air getting to it) and the screamin eagle exhaust. I am about to replace the air breather with a higher air flow unit, so I will not be making any adjustments until I install it.
There was one oddity - I took the breather off just to check on something - and when I would acclerate it, some gas vapor appears to blow back out of the carb at slight/mid acceleration (standing still). I may sound like an idiot here, but I thought the carb just sucked - it appears to blow, too (lots of possibilities with this thread). It does appear that I am smelling more gas when around the carb then I should.
Any thoughts?
My thoughts are that my middle jet is wrong - this is a 96 carb (can't remember the jetting). Right now it has the stock air filter (which means very little air getting to it) and the screamin eagle exhaust. I am about to replace the air breather with a higher air flow unit, so I will not be making any adjustments until I install it.
There was one oddity - I took the breather off just to check on something - and when I would acclerate it, some gas vapor appears to blow back out of the carb at slight/mid acceleration (standing still). I may sound like an idiot here, but I thought the carb just sucked - it appears to blow, too (lots of possibilities with this thread). It does appear that I am smelling more gas when around the carb then I should.
Any thoughts?
Seasoned HDF Member
Joined: Aug 2007
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From: NW AR
Coughing/sputtering like that is a sign of too lean. Check to make sure you don't have an intake leak. Changing the air filter will likely make it worse, if you don't change something else. It is normal for carbs to have a vapor cloud as you describe. It is usually inside the air filter so you don't notice it, and the amount may depend on how the motor is cammed.
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Road Captain
Joined: Apr 2010
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From: Texas
Coughing/sputtering like that is a sign of too lean. Check to make sure you don't have an intake leak. Changing the air filter will likely make it worse, if you don't change something else. It is normal for carbs to have a vapor cloud as you describe. It is usually inside the air filter so you don't notice it, and the amount may depend on how the motor is cammed.
Last edited by hillcountryflt; Aug 27, 2010 at 08:17 AM. Reason: missed a leak source
Seasoned HDF Member
Joined: Aug 2007
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From: NW AR
Do the old trick of spraying some carb cleaner around the joints while the bike is idling and see if the engine sound changes. You probably don't have a leak, but check it that way. After that, change the air cleaner if you're planning on it and tune the slow speed circuit. I don't know CV's, so can't help you there.
Oh, I think I have a gas tank and a seat that fit your FLT. Seat needs new foam (old is really hard). The vinyl was good last I looked at it 10 years ago (brown), tank had some rust inside but not too bad. $20 plus shipping and they're yours.
Oh, I think I have a gas tank and a seat that fit your FLT. Seat needs new foam (old is really hard). The vinyl was good last I looked at it 10 years ago (brown), tank had some rust inside but not too bad. $20 plus shipping and they're yours.
Road Master
Joined: May 2005
Posts: 1,121
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From: Mass.
First make sure that the accelerator pump is operating, this is simple to check by removing the filter and with the engine off but fuel on, roll the throttle and see if fuel squirts into the carb throat. If not, check the rod on the left (facing front) of the carb to make sure it is not sticking in the boss that supports it. If so lubricate it. If the pump is being operated then you will need to clean the ports. Remove the pump cover and clean the passages with carb cleaner. Inspect the diaphragm for tears or leaks, replace it if needed.
In either case, the bike will ru,n better at low speed with a number 45 low speed jet. That may be all you need but you will still need to make sure you have an accelerator pump.
In either case, the bike will ru,n better at low speed with a number 45 low speed jet. That may be all you need but you will still need to make sure you have an accelerator pump.
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Road Captain
Joined: Apr 2010
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From: Texas
Checked the accelerator pump. I shoot two squirts every morning on first start. It is a little off center, but that is about it. I plan to pull the carb and verify jet sizes tomorrow - if I can a magnifying glass to read the numbers on the things.
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Road Captain
Joined: Apr 2010
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From: Texas
Have not had an opportunity to upgrade the jets on the carb. I did finally get in my mounting bracket that would allow me to mount my high-flow air breather. There is some stutter, but there is a substantial improvement in low speed power. Some minor hesitation at take off and I suspect this is where rejetting will make the difference.
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1982, 883, acceleration, carburator, flt, fuel, harley, ignition, initial, injected, motorcycle, sputter, sputtering, sputters, stock, stutters
