I got a 1980 honda express for free and some friends and I have been wrenching on it for two days now. We cleaned the carb, attached an air filter, fixed the oil pump, and we can get it to start up about once for every 20 tries. We've adjusted the carb every which way and can't find a good adjustment that it runs consistently on. When it does run, it will run for a minute and then cut out. Also, it cuts out when the throttle is wide open. Does anyone have an idea what we can do to make it start and run consistently?