Had a bad stumbling prob off idle with an '05 Fatboy --would bog down badly--if I goose it, it will run but still stumbles til higher RPM's and then it will go.
Took carb off an '04 FXST and put it on the '05 Fatboy--ran great.
Looks like it is the idle/slow jet circuit--I have had this carb apart several times cleaning it and blowing orfaces with compressed air but still stumbles big time off idle. If I goose it, it will stumble and then catch and run. I have a brand NEW slide (not pinched) and slide works fine when I give it throttle. I have also checked the accelerator pump diaphram and it looks fine--no tears. Any ideas. Idle mixture needle is turned out 21/2 turns on both carbs. I have put the Slinger jet kit in both carbs--'04 FXST runs great with it. Took the DynoJet kit out of Fatboy and replaced it with the Slinget kit thinking that would solve the stumble prob--didn't. How can I clean the idle and slow jet circuits or is there a particular problem someone has experienced with these circuits?
Any help is appreciated.

 

Try a larger pilot jet...46 to a 48

 

Just curious...did you inspect the accelerator pump diaphram for holes or tears? The accelerator pump is responsible for the initial fuel delivery off of idle. Any hole or tear in the diaphram will reduce the amount of fuel needed and cause the symptoms you described. Good luck!