So I’ve had this 2001 Fatboy 88ci for 2 months. The guy a bought it from said it ran fine when he last parked it( it sat for 2.5. Years in his garage) it is stock as far as I know. It has a mikuni hsr 42 and k#n air filter and Vance and Hines straight shots. The mikuni had a 165 main jet, 25 pilot jet, # 70 ac nozzle, and a #97 needle clipped in the middle. I’ve cleaned and replaced all gas lines and thoroughly cleaned the tank and rebuilt the carb, also got rid of the vacuum operated petcock and sealed off the ports the bike idles fine and WOT is great. My problem is more is the cruising range. It seems to almost misfire and hesitate and then I have to open throttle to get it to stop. The bike is running extremely rich still and I have gotten down to a 20 pilot and the #70 needle clipped all the way at the top and installed a #50 ac nozzle with the starting point gapped way bigger then the suggested .080. I have a 98 needle in the mail along with a 17.5 pilot jet. Am I going in the right direction here?? My gas mileage has improved from 12 mpg to 24 now, but damn this girl is rich. Also right now my fuel mixture screw is backed out 3 turns.

Thanks for for the help

 

I have the same set up. I had that problem and found the round rubber carb to manifold mounting gasket was cracked in several places. You can’t see that until you remove the carb. Replaced it and it was like riding a different bike.

 

Thanks! I have changed out my manifold to carb gasket and I have sprayed to check for leaks and so far I haven’t found any. It seems to be making progress with every smaller jet I install. Just making sure this all sounds right.