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Discussion Starter · #1 ·
Hello all and welcome to my holiday mystery novel! This is my first post on the HD forums and I would like to thank each and every one of you for your contributions in subsequent posts that got me to were I am at this very moment with my sportster. Let me set the stage...

I purchased a 2006 Sportster 883 XL Low with 2,600 miles after owning a brand new Husqvarna Vitpilen 401 that was totaled in a hit and run in the beautiful, sunny, and downright treacherous MadMax-type driving conditions in South Florida.

The sportster ran rough when I took possession with the issues being a very low idle rpm, constant blipping of the throttle to keep it lit, black smoke on idle, and an annoying carb cough (rich condition misfire to be specific). Already installed upon purchase was a Screamin' Eagle stage 1 air cleaner, Screamin' Eagle ICM, and Screamin' Eagle exhaust pipes. THATS IT!

I gave the carb a thorough clean and rebuild with new gaskets, diaphragm pump, float needle and the works. I have left all jetting as I found it. 42 pilot, 165 main, and an aftermarket needle with the washer set third slot from the top and three washer spacers beneath it.

After putting 1,400 miles on the bike since purchase I have not been able to shake a consistent rich fuel mixture condition! She'll start up just fine and run like a top at speeds but at idle the rich fuel mixture symptoms keep haunting me.

Up until this point I have done as follows:
New spec spark plugs and gapped to manual's specifications (they keep fouling after riding for short periods and I keep cleaning them off with no luck with my attempts to solve the issue)
New spark plug wires
Carb thoroughly cleaned and rebuilt
Air filter (K&N) cleaned and oiled
Tested intake manifold gaskets (wd-40) with no signs of leaking
Intake manifold to carb boot replaced
Vacuum operated petcock (stock) was leaking a bit and thought fuel might be finding its way into the carb through vacuum line - replaced with standard petcock and vacuum nipple plugged on carb

Additional info:
During rebuild, float needle was replaced and float readjusted as per manual's specifications
When adjusting fuel mixture screw (aftermarket knob-style) the bike will start to stumble at 1/2 turn out from full seat. even when running at this fuel mixture setting, spark plugs are still fouling.
This bike is daily driven approx 10 miles. 5 miles to work, and 5 back. It is not ridden hard, never taken on highways, and rarely gets past 50mph.

Things I think are causing the issue at this point in time:
Stuck/faulty enricher circuit - Its possible I missed the enricher port and cleaning deep inside with a small pipe cleaner and it is possible the enricher circuit is not fully seated therefore allowing excess fuel into the throttle body at idle causing this persisting rich condition
Faulty ICM
Faulty Ignition components (coils etc)
Faulty crank position sensor (dash is not throwing any cods for CPS but will check with multimeter regardless)

Through all of this, the bike is still fouling plugs quickly and causing a misfire (backfire through carb) only when revving throttle at idle or from idle. No issues in mid range/top end whatsoever!

I've done all of these diagnostics myself and am hoping to get to the bottom of it after spending all of this time and research, and I want to keep my hard earned Benjamins for some cool bike parts down the road instead of giving it over to the Harley dealership mechanics!

Any help would be greatly appreciated. Fingers crossed I can get my mystery solved!
 

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Hello all and welcome to my holiday mystery novel! This is my first post on the HD forums and I would like to thank each and every one of you for your contributions in subsequent posts that got me to were I am at this very moment with my sportster. Let me set the stage...

I purchased a 2006 Sportster 883 XL Low with 2,600 miles after owning a brand new Husqvarna Vitpilen 401 that was totaled in a hit and run in the beautiful, sunny, and downright treacherous MadMax-type driving conditions in South Florida.

The sportster ran rough when I took possession with the issues being a very low idle rpm, constant blipping of the throttle to keep it lit, black smoke on idle, and an annoying carb cough (rich condition misfire to be specific). Already installed upon purchase was a Screamin' Eagle stage 1 air cleaner, Screamin' Eagle ICM, and Screamin' Eagle exhaust pipes. THATS IT!

I gave the carb a thorough clean and rebuild with new gaskets, diaphragm pump, float needle and the works. I have left all jetting as I found it. 42 pilot, 165 main, and an aftermarket needle with the washer set third slot from the top and three washer spacers beneath it.

After putting 1,400 miles on the bike since purchase I have not been able to shake a consistent rich fuel mixture condition! She'll start up just fine and run like a top at speeds but at idle the rich fuel mixture symptoms keep haunting me.

Up until this point I have done as follows:
New spec spark plugs and gapped to manual's specifications (they keep fouling after riding for short periods and I keep cleaning them off with no luck with my attempts to solve the issue)
New spark plug wires
Carb thoroughly cleaned and rebuilt
Air filter (K&N) cleaned and oiled
Tested intake manifold gaskets (wd-40) with no signs of leaking
Intake manifold to carb boot replaced
Vacuum operated petcock (stock) was leaking a bit and thought fuel might be finding its way into the carb through vacuum line - replaced with standard petcock and vacuum nipple plugged on carb

Additional info:
During rebuild, float needle was replaced and float readjusted as per manual's specifications
When adjusting fuel mixture screw (aftermarket knob-style) the bike will start to stumble at 1/2 turn out from full seat. even when running at this fuel mixture setting, spark plugs are still fouling.
This bike is daily driven approx 10 miles. 5 miles to work, and 5 back. It is not ridden hard, never taken on highways, and rarely gets past 50mph.

Things I think are causing the issue at this point in time:
Stuck/faulty enricher circuit - Its possible I missed the enricher port and cleaning deep inside with a small pipe cleaner and it is possible the enricher circuit is not fully seated therefore allowing excess fuel into the throttle body at idle causing this persisting rich condition
Faulty ICM
Faulty Ignition components (coils etc)
Faulty crank position sensor (dash is not throwing any cods for CPS but will check with multimeter regardless)

Through all of this, the bike is still fouling plugs quickly and causing a misfire (backfire through carb) only when revving throttle at idle or from idle. No issues in mid range/top end whatsoever!

I've done all of these diagnostics myself and am hoping to get to the bottom of it after spending all of this time and research, and I want to keep my hard earned Benjamins for some cool bike parts down the road instead of giving it over to the Harley dealership mechanics!

Any help would be greatly appreciated. Fingers crossed I can get my mystery solved!
Bingo !
 
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Discussion Starter · #4 ·
Well, I thoroughly cleaned the enricher port and replaced the enricher assembly and am still running rich at idle, soiling plugs and coughing a bit. Still running a 42 pilot jet with 2 turns out on the mixture screw. Turing the mixture screw got the bike to idle high and had to lower idle via the idle screw to get it to stumble. I am baffled! should I try a 40 pilot jet?
 

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an aftermarket needle with the washer set third slot from the top and three washer spacers beneath it.
That needle seems really high to me. The needle shouldn't affect the idle normally, but an aftermarket needle up high - maybe??
 
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