Trying to fine tune my carb after a long bout with leak and electrical issues. 97 FXDWG with short shots and ness big sucker 2 air cleaner. 48 pilot, 180 main and 1 shim on stock needle.

Any help with a direction to tweek is appreciated

What Im hearing and feeling are these things:

-Lots of little surging when on minimal/cruising throttle...not sure if this is because I am too high of a gear for the rpm (I am a rookie). Once I get higher in rpms it doesnt do it.

-I get backfire pop from exhaust on some throttle blips

-runs better with the throttle out a smidge

-almost have to turn completely to seat to stall engine with mixture screw.

-real rough in general off idle.

Assume the carb is super cleaned out and with new parts and rubber both. New petcock, filter, amd hoses

 

Try a 45 pilot.

 

I had similar symptoms with the surging, a replacement slide/piston and diaphragm fixed it. The cast aluminum slide/piston was worn.

Check the brass piston on your enrichiner. It's about a 10 dollar part. The piston has a rubber seat pressed into it from the under side. It seals out fuel flow in the closed position. It's hard to see but it is there, that can be worn also. YD

 

I replaced the choke cable last season. When going over everything I removed it and took a look. Looked brand new. Sprayed some carb cleaner and air and called a day.
my problems start right at cruising level throttle. Just past take off. Little less throttle or a little more open (half throttle) it is fine. But theres a distinct point of throttle openness where it happens every time

 

Common errors:
Tiny o-ring and washer reversed or missing on mixture screw.
Needle jet upside down (curved inside faces needle and extends into carb throat)
Intake leak
Damaged vacuum diaphragm

Tips:
TC88 start with 48 slow, EVO start with 45
If you need more than three turns on the mixture screw out, go up a slow jet size.
If it runs better at cruise with choke, you need a different needle profile or a shim

 

N65C needle shimmed .040

 

46/180. 1.5 turns on screw. Now shim. This is with the choke pulled an rch-pushing it completely in causes all kinds of mayhem of coughing and sputtering and nesr dieing

 

If it's severe and you rebuilt the carb and have no intake leaks or vacuum diaphragm leaks, would refer back to post #5 especially the second item about the needle jet being upside down.

 

im 10000% certain needle jet holder is in correctly. I dont hear any change in rpm with air sprayed around manifold.

Ive put 2 different aftermarket air cleaners replacing intake grommet each time of course, same problem in same throttle ranges with both air cleaners. Same issue with 45,46, and 48 pilot jets and the whole air fuel screw turn range. The only change is some backfire thru exhaust with 48.

I have a base gasket leak if that matters
With the hypercharger air cleaner I was getting oil leaking at the engine.

 

I get this. All the time.