Acted like misfire since day one and also spit / backfired trough carb
Bruce Carpenter
2005 FXDC Carbureted, Stage 1, Screaming Eagle exhaust, No motor work / stock. Acted like misfire since day one and also spit / backfired trough carb. So chased carb problem first. Picked up re-jet kit from HD and installed slide spring, emulsifier tube, jets 48 and 185. Drilled out air mixture and installed adjustable needle. Set needle 3 1/2 turns out from seated. Reinstalled carb and started bike. Got up to running temp and adjusted air mixture out to 3 3 /4 for final best smooth idle. Blows black puff out pipes on acceleration.
Harley said go back to 45 jet. Now popping back out through carb so I found a 46 jet and this seemed to relieve this problem. Now only pops out carb after a long idle when rolling throttle or after running down highway and stopping at and exit then accelerating after stopping. Now to the misfire. Front plug white, rear plug black dry soot. At idle you hear it drop / miss about every ten seconds. At highway or any steady speed for that matter you can hear it drop off about the same ten seconds. During acceleration it pulls hard and strong. Deceleration you get the typical back rumble with a dead sounding thud in there. My Harley shop didn’t find anything during my maintenance plan when I complained. Never mentioned anything about codes.
I’ve changed plugs about 2x per year. Platinum’s didn’t help. Changed wires and same thing. Sprayed carb cleaner around intake etc… and no change in idle. So now what I guess? Oh yeah, this twin cam is about the noisiest damn motor I have had and compared to others around it. Always since day one, sounded noisy like a loud ticking lifter or valve train. Way noisier than my ’90 EVO with 50k and my ’89 Sporty with 39k. This Twin cam only has 18k. Harley said some are noisier than others. Any ideas so I don’t just start part swapping? Thanks