[wbergt]

I have a 2002 shadow spirit 750 that backfires in the rear cylinder only on both accel and decel at between 1800 &2000 rpm. Carb is set properly, plugs are tan. Coils plugs and wires are good. No exhaust or intake leaks. Could a faulty iginition pickup or ignition pulse generator cause this?

 

[Chopped 02 Shadow]

I have a 2002 shadow spirit 750 that backfires in the rear cylinder only on both accel and decel at between 1800 &2000 rpm. Carb is set properly, plugs are tan. Coils plugs and wires are good. No exhaust or intake leaks. Could a faulty iginition pickup or ignition pulse generator cause this?

I just had a similair problem.. my float seemed to be stuck. What i did (might not fix your problem), is open the drain screw on the affected carb and let some fuel out. My problem was popping/backfire when at a constant speed. acceleration got rid of the pop/backfire until i got back to a steady speed.

 

[jpr1968]

I would double check your intake. Check the carb boots to make sure the clamps are tight. If it was ignition it would probably effect the whole RPM range.

 

[over60ncrazy]

I had a severe backfire in rear cylinder and it was a carb cleaning that solved my problem.