71 cb750 misfiring help!!!!!

[750cafe]

  Heres the lo down on whats been done to the bike... its a 71 750 stock carbs,cam, aftermarket exhaust,DYNA electronic ignition... Now in mid range of the throttle it pops and backfires.... there isnt any vaccum leaks..... could it be the timing? The bike has been sitting for 8 years and I dident pull the carbs off and cleanthem cuz the float bowls were amazingly clean... Could somthing be in the jets or maybe gummed up????




     Cheers,


        RIch

[woodsrider250-2]

Yes.

Clean them.

Jetting could be off too.