Hi Gang,
I'm new here. I just picked up a brand new, rebuilt, 1981 CM400C. It's been "rock and roll" bobbered/bratted out with shorties etc. My question is, everytime I downshift into second or third and let out the clutch it pops and backfires like the fourth of July. Some of the backfires are pretty damn loud... I've never owned a twin before. Is this just due to the twin with the shorties and completely normal? Or do you think I'm running lean or there's something else wrong...?
Does anybody know this bike? Thanks so much and ride safe!