Motorcycle Repair: 1982 Honda Nighthawk 450 CARB issues, 1982 honda nighthawk, honda nighthawk 450

Question
Backfires from carbs where they attach to the engine... Runs and idles fine,  JUST BACKFIRING.  It has about 40,000 miles??

I cleaned the carbs twice, installed new needles in both carbs, replaced air filter, ran Seafoam throgh a couple times and   cleaned fuel petcock bowl and screen...

seems like its missing...  mainly happens while idleing.  Seems like if you pull the choke in, it levels out and drives pretty smooth!!!

PLEASE HELP!!!  The bike is rideable, but , trying to teach my wife how to ride and she get scared when the bike does this....

A friend of mine says that it may be a valve issue???  please help
!!!

Thanks  Mike

Answer
Check the primary as well as secondary carb circuits.  A blockage in a secondary circuit will cause backfiring.  Also check the timing, as well as the valve clearances.  It is all about having the right fuel mixture, the right compression and the right ignition timing...  Upset any one and you could have the problem you describe.

Good luck,  Jan