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Rear cylinder misfire ?

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  #1  
Old 02-10-2019, 04:20 PM
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Default Rear cylinder misfire ?

I have a new to me 2003 Electra Glide Standard, CV carb, Dual exhaust, previous owner said to have had cams installed. My issue is that the rear cylinder misfires or pops when idling and faster when at higher RPM , the rear plug is dark, I changed it and still the same, I changed the plug wires, still the same. thought maybe I had an intake leak sprayed a lil wd 40 around manifold connections and no change. the carb has been gotten into by somebody at some point mixture screw cover has been removed … badly but it does adjust. have to have way out farther than they say for it to run right.... so to be descriptive it just sounds like pop pop pop....pop pop pop....pop pop pop … and faster and a bit more skippy at RPM. it does also occasionally backfire thru carb, im leaning toward a carb problem on this or pushrod adjustment? The thought of dumping the CV carb for an S&S has also crossed my mind but I wanted to see if I can make it work before going that far. Any opinions ? im a mechanic in other areas but ive not done bikes, however im not afraid to give it a go at all so any help would be appreciated.
 
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Old 02-12-2019, 04:11 PM
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If the Idle Air screw doesn't get it well then the idle jet is too small. I would look at CVP and get their tuners kit to really work this out. I have had great luck with the company and great results. https://cv-performance.com/
 
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Old 02-12-2019, 07:24 PM
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You are describing a very common issue that requires a couple mods to get it close.
The easiest fix is to replace it with a Mikuni 42. Take it out of the box, mount it up according to the instructions, fire it up and adjust the idle air screw. Then ride and enjoy your bike because Mikuni has done the homework for you and the carb comes with very close jetting for stock to mild builds.
FWIW the CV or the Mikuni are better resolves than the SnS IMO.
Bob
 
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Old 02-12-2019, 08:55 PM
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Is the pop through the intake or exhaust? Did you do the basics such as a compression test. On a CV, if more than 3 turns out, you need a larger slow jet, but you really don't know if the carb is even properly reassembled.

I would advise checking all this before throwing parts at it.
 
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Old 02-13-2019, 09:28 AM
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Too many possibilities possible from what you describe. Find a local indy who can see and hear your bike running and will have a far better chance IMHO at diagnosing what is wrong. That will be a lot quicker and cheaper than trying to nail the problem yourself.
 
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Old 02-13-2019, 11:06 AM
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Originally Posted by grbrown
Too many possibilities possible from what you describe. Find a local indy who can see and hear your bike running and will have a far better chance IMHO at diagnosing what is wrong. That will be a lot quicker and cheaper than trying to nail the problem yourself.
Good advice right there as well.
Bob
 
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