I have a 94 fatboy with a keihin CV 27206-93 that is running so rich that the oil smells like fuel and your eyes tear.Has run like this for the last 8 months but has recently gotten worse.Went to the gas station and Itopped off the tank and when I restartedit barely made it home chugging, spitting, farting and popping while smelling real rich.Drained the tank new plugs and it went about 5 miles before fouling out the plugs again.I think the gas station may have just been a coincidence.

The bike is running a thunderheader with a screaming eagle ignition.The carb has a 165 main jet and I believe a 42 slow jet.The float has been reset at 12 mm.I have gone through the carb and cleaned what I believe was every orifice that is I there.I also bought a carb rebuild kit including accelerator pump, vacuum piston (which I did not drill) and a yost air screw.The float pin would not come out even with hammer and punch, so to check operation I floated it in a clear bucket, and then attached the fuel line and shut off the fuel by manually raising the float. It appears to be functioning perfectly.
Reinstalled and seem to run a little better, not perfect, but after about 10 miles it fouled another set of new plugs as it still runs real rich.I took the carb off my 93 sporty 883 which is running a 170 main with a 45 slow jet and installed it on the fatboy, that now runs well.I have now transferred the problem to the sporty with the fatboy carb, so I know the issue is with the carb.
Recap:
Bike runs real rich
165 main jet
42 slow jet
Float set at 12 mm
Yost air screw can be turned all the way in and the bike still runs.
Any ideas would be greatly appreciated.
Ron

 

Enrichener closing fully? Holes in the slide diaphragm, or pinched when installed?

 

Like outlaw stated is the choke (enrichner) fully seated?

Also how does the tip of the air screw look? Or the carb body where the air screw seats?

I'm no CV pro but if you can fully seat the air screw and the engine still runs that would be the first area if be searching.

 

Did you do anything 8months ago or did she just start running this way? If you were in the carb before did you put the mid range needle jet in upside down?

 

sounds like a float not seating or you installed the mixing tube upside down.


I meant needle jet I forgot it was separate on the CV.
and I see kona mentioned it already.

 

Would the cable sealing cap on the enrichner if cracked cause me a problem? It did not look perfect.


I bought the bike a year ago and it ran a little rich for me from the start. I just attributed it to being jetted rich when the original owner put the thunderheader exhaust and k&n air filter.


It had a stock screw in it that I removed and installed a yost. Everything appeared clear. Interesting thing about the yost is when fully seated it actually sticks a tiny bit into the throat of the carb.




I pulled the top of the carb off and the vacuum diaphragm looked good but I replaced anyway while I was in there. I did not remove the enrichener, but did move the cable with the top off the carb and it moved back in forth and appeared fine. The tip appeared clean and moved smoothly. I will pull it again and make sure it seats.


Any other ideas while I am in there?


What about setting the float between 14 and 15 mm?

 

if its cracked replace it
and the low speed screw can stick out a little when seated
I would still check the needle jet make sure its not upside down

 

With the jets you have listed, it is not jetted rich. The pin on the float usually comes out pretty easy. Are you tapping it in the right direction?
From the Service Manual:
The arrow indicates direction of removal. Tap pin out from INTERFERENCE SIDE pedestal {direction of arrow): install pin from LOOSE SIDE pedestal (opposite arrow).

 

Hey Guys,


Thanks for the suggestions.


I am going to pull it down replace the cap on the enrichner.


I tried the pin both ways, but while in there this time I will pay more attention to the arrow and give it a harder wack.


If I can get pin out I will check/clean seat and replace the needle.


I will give you an update after I get it down.


Thanks,


Ron

 

Hey Ron....... answer the question on your other carb thread.