I have a 1983 [?] Honda 200M that is driving me nuts. It will not cold start if you touch the throttle or choke. It acts too lean but the choke doesn't help at all. You just have to turn over [electric start] forever and maybe diddle the throttle slightly until it will start and keep idling then give it gas and it will be fine and start instantly and run perfectly the rest of the day. When it's freezing this is almost hopeless. Carb has been off and cleaned four times and checked for vacuum leaks to intake. Has plastic float level deal which seems not adjustable but somehow I think it must need to be richer at cold start. Choke does nothing? I'm badly missing something but no idea what. - Any thoughts?