So I have 97 FXDWG. CV carb with arlen ness big sucker 2 and VH short shots. i have a 45 pilot and 180 main and fuel mix screwed out 3 turns. Right off idle Im getting like spitting/puffing sound. Kind of like the sound of getting a hair from your mustache in your mouth. The sound that youd make spitting it out. I get it almost every time I take off. Doesnt do it in Neutral when Im stopped and blip the throttle. Only when I crack the throttle open to take off. Ive had a 46 pilot in (1 1/2 turns on air/fuel mix) and it did the same. Any ideas where to make adjustments

 

Sounds like still a little lean. We call that a cough. Most commonly caused by a lean condition.

The question is: Is this a new condition? Is it lean because your intake manifold seals are old and leaking? Or the carb to manifold seal leaking?

Are the air cleaner and pipes new? That will cause a lean condition and requires a re-jetting.

Leave the main alone for now, check for leaks with the intake seals (forum search for IM leaks-however, I would change them and the carb to manifold seal, especially if never changed), then if those are all sealed up tight and still have the problem, go to a 48 slow. YD

 

Not new pipes or AC. Used wd40 to check for leaks a while ago and found one on front of intake manifold. Rebuilt the carb so theres new rubber on all three sides of the manifold. I set up float height at midpoint of spec with new valve.

Would a malfunctioning piston cause this issue right off idle. I open the throttle I see that the piston goes up and down, but when I use a can of air into the port to try to move the piston that way, it doesnt move. There are no tears in the rubber of the piston and Im certain its not pinched as I used caution when I put that on (thanks to Shane Conley videos on youtube)

I had a 46 pilot before I put it away for those months
and it did the same. When I shimmed the needle with 1 thin washer, I got massive backfire when I opened the throttle.

 

A 45 and a 46 is not much difference. Like one turn of the adjustment screw difference. So try a 48. As long as the piston goes down at a steady pace, and you feel/hear air moving when uou slide it up or down slowly by hand, it should be good. Was the slide ever drilled out? If it isn't, then don't drill it.

The piston will rise with engine vacuum if all is good. Is it worn to where you have lots of play in the piston/piston bore? I replaced my piston just because of the wear to it. Hard to tell how much wear is to much, unless you have a new one to compare to, but something to consider.

Have you checked for manifold leaks since replacing o-rings? YD

 

The hole in the slide was drilled when I got bike. I think a checked with some drill bits and think it stoppes fitting after 1/8" bit. But I cant remember for sure. I had to order a 48 pilot. I live within 20 miles of 6 different HD dealers and not one had a 48 in stock

 

Outside of looking at the plugs and reading them, what type of physical things should I look/feel if the pilot is too rich?

 

If you get the bike rich you'll notice it on a hot restart because it will become easy to flood.
As you get it richer you might think you feel it hitting harder every time it fires.
You might think you hear more combustion sounds.
You might even say the exhaust got louder the richer it gets.
I use these things, mpg, plugs, and also how it runs overall to tell.
My 80" w/CV is 48, 180, 2 turns, and 2 shims. 46mpg yesterday 2/up running 55-60 mph on 93 octane gas. It ran good imo. 3 shims and it would of been 43 mpg or so I think.
Good luck.

 

So after putting in a 48 pilot from the 45+46 (coughing) I am getting this. I am 1 1/2 turns on air fuel screw. No change if I increse turns and I can go all the way in to seat without stalling out. Stumbles alot at seat but still goes. Im about going up to maybe 20% throttle

 

46 pilot. 4 turns out. Cough often taking off. No backfire.

 

I think I can hear some hesitation in there.
There are several small holes in the carburetor that can get clogged up. Did you rod all them out when you rebuilt it?
i'm not a big fan of changing the needle or drilling the slide. A small hole in the rubber cup on the slide can cause it also.
How does the plugs look?