backfiring out carbs

[thunder750]

 Have been putting bike together for about a year now.1978 CB750K model ran before starting to restore.Replaced all wiring & complete charging system.Bike has dyna ignition & coils.Tried to start bike fackfired threw carbs & caught carbs on fire.Any suggestions what to check Greatly appreciated.

[Edited on 4/7/2005 by thunder750]

[mark m]

Your coils may be attached the wrong way round. Try swapping the blue/yellow wires at the coils.

[CBen750F1]

or you might have your advance mechanism out 180 degrees, if you take it appart, and dont put it back together right the magnet on the crank will be out 180degrees to the cams... common prob ..peace