alright, i've got to say i'm not really surprised...but i don't like it

after a complete frame-off restoration i finally completed the bike....just waiting on a leather bare bones to complete the look

anyway, i tried firing it up today and BANG!...i got a mother of a backfire... like someone fired off a 12 gauge right next to my ear....was even a spark that shot out

console me, give me some suggestions about what could have caused it, offer me words of encouragement that it's okay to try and start it again....LOL

paul

 

How long has the bike been laid up for? Sounds to me like a leaking needle and seat.

 

Cam timed wrong or pushrods loose not allowing valve to open or
Close?

 

hi pete.... can't be that...carb was a rebuild as well

and ride, i don't think it's that..... i rebuilt that engine, too... andrews 27 and new SE pushrods....had it in my basement for months doing the rebuild, and when she was complete, i made sure pushrods were on point with each stroke

i'm thinking it's because i inadvertently dumped a **** load of fuel into the carb by twisting the throttle completely open about 5 times before i started it.... wasn't thinking

 

Simple, Ignition timing, cam timing, pushrod adjusted wrong holding valve open, or if it's single fire try reversing the plug wires. Hope this helps.

 

My 97 Heritage does this also, but only after the bike is warmed up. If I ride and warmup the motor and say I have to stop and get gas. It will backfire and it is Loud, women and small children crying and running in all directions. It's embarrassing as hell. The thing is it doesn't do it every time though. I have a new rebuild kit for the carb, going to try that and see if it helps.

 

yah, i'm thinking the ignition timing...cause it did it again

don't think i had it at TDC on the compression stroke while adjusting it

and yes, gump...it is single fire...reverse the plug wires?

 

JSBRIDGEW,
Standard Harley ignition is "dual fire" which is a wasted spark ignition. The coil fires both plugs at the same time. Most aftermarket fire only one plug at a time, hence the term "single fire". So if you have the front wire going into the coil tower for the rear cylinder obviously the rear is is the wrong one too. This is the same as having some plug wires in the wrong place on your car, it can cause backfiring. Hopefully this makes sense. Changing the plug wires around is easier than rewiring the coil. Hope this helps.

 

ah....you are correct, mia

i installed a single-fire twintec that eliminates module and places everything in cone.... and in my ignorance i didn't bother to notice the plugwire configuration on the wiring diagram....just assumed it would be same as stock....damn

so...swapped the wires, and timed it properly according to comp stroke at TDC

should be good to go

 

Glad to be of assistance.