I recently finished rebuilding a 1982 CB750C; body, electrical, engine, carb, etc. I fired it up for the first time the other day and boom - she came to life. That was cool. Everything seems to be okay except for a problem with the idle/throttle. I can start the bike and it idles okay, but when I put a little throttle to it the bike revs high and stays high. I can bring the revs back down by putting it in gear and using the brake, but it will head north again with throttle, sometimes even without, and it seems to get worse with temp. I was thinking lean condition/vacuum leak or perhaps somehow related to the spark advance. I did the spray test around the boots (which are new), vacuum lines, etc. with no luck. I double checked the jetting and pilot screw setting on the carbs (stock settings). I did a strobe test on the spark advance and it's good. So at this point I seem to be at a loss and could really use some guru advice. Note that the throttle cables and butterfly valves seem to be working fine.