Your bike has an idle stabilizing circuit. Timing is 7,5 degrees at idle in neutral at about 1250 rpm. When put in gear the change switch sends a signal to the cdi and raises the timing to 15 degrees and the idle to about 2200 to compensate for the load from the torque converter. You might try putting the bike on the stand and see if the timing changes when shifted in gear. Do you have a FSM? timing mark"FN" 7.5 degrees in neutral . "F" mark 15 degrees in gear. At idle. This from my CB 400 a manual but should be the same.