so my 2002 fxdp has the hi flow air cleaner with K/N and vance and hines short shots. all installed previous to my ownership. bike pops alot on decel and will backfire thru the carb on takeoff occasionally. took carb apart. had a 45 slow jet and a 180 main. went to the dealer to get a 48 slow and a 190 or 195 main. and get the sportster needle. he said just to change the slow not the main. i did but am second guessing myself. the plugs before the jet change were white. repl with new. i just dont think the slow will affect it that much. test drove not much changed.
question: what jets are you running with a similar setup? i know this should prob. be in another forum catagory but think of it more as a poll to see who has what jets.
thanks for readin

 

Unless you have a Dynojet kit in your carburetor, a 180 main jet is pretty small. If you do have a Dynojet kit, Keihin main jets won't workwith the emulsion tube...the threads are different.
The stock 45 slow jet should work fine if you have the idle mixture screw adjusted correctly. If you don't, that may besome ofyour popping and carb backfiring. The stock 190 main jet also should be fine with the stockKeihin emulsion tube. The Sporty needle works great, get it! This setup worked good for me on an 03 Dyna with air cleaner and pipes, and later with 95" cylinders and 203 cams.

 

What brand of carb do you have on your FXDP?

 

just a stock carb. the slow jet increase helped the idle and i could adjust the idle mixture down but it still pops on accel. i think i'll pick up that main and sporty needle tomm. thanks murphdog

 

Your pipes may not be on tight. Check the bolts...