Finally got this 76 CB750A with a 78 wire harness and 78 indicator running after cleaning the carbs. I asked earlier if the rear wheel spun in Neutral and some people said, "Yes." It starts in Neutral with the side kickstand down. Wheel spins and can't be stopped with your foot. Apply gas and the wheel spins faster (like it might be in "L" gear). Raise side stand and pull shift lever up and it goes into "L" and the wheel stops. Add throttle and wheel stays stationary. Pull shift lever up again and it goes into "H" gear, wheels starts spinning and will go faster if you add throttle. Drop the side stand and it goes back to Neutral and wheel keeps spinning.