Back firing and poor running.

[Montana]

1979 xs650 that was oil fouling left plug. I disassembled and re-ringed and ball honed cylinders. Cylinder are within std specs. After assembly bike would run only with plug wires switched for left to right. I figured i messed up cam timing and went back and redid following chiltons manual. Now bike starts but backfires and has hard time running. Sudco carbs have been cleaned but seems like it's not getting fuel or there is weak spark? I have performed timing and points procedure per chiltons manual without any issues. Any ideas. Could the condensor be failing?

 

[retiredgentleman]

1979 xs650 that was oil fouling left plug. I disassembled and re-ringed and ball honed cylinders. Cylinder are within std specs. After assembly bike would run only with plug wires switched for left to right. I figured i messed up cam timing and went back and redid following chiltons manual. Now bike starts but backfires and has hard time running. Sudco carbs have been cleaned but seems like it's not getting fuel or there is weak spark? I have performed timing and points procedure per chiltons manual without any issues. Any ideas. Could the condensor be failing?

Have you used a timing light? That's the only way to get the timing correct.

Also, make sure your charging system is putting out 14 volts or better at approx. 3000 rpm.

Its normal to have a small amount of sparking at the points, but if you see a lot of sparking, then replace the condensers.