I think the difference is that mine will run as long as I have some throttle on it but if I let off it will die. I can run all day long as long as I don't stop, if I stop and try to take off again, is where I have a problem. From what I've been reading, you should rebuild your carbs and your low and high speed jets. Also if your bulb was compressing, there is a fuel restriction either in your tank or the fuel lines. Good luck and hope this helps.