Well, I've never been a big believer in a motor rebuild in a bottle,but I ran Seafoam through my motor this weekend,and I've got to say,I'm impressed. I don't know exactly what it did,but now this 33 year old engine that has sat for atleast 10 or more years,starts on the first pull almost everytime,even cold.I don't think it did anything to the carb,cause I just rebuilt it.Maybe it freed up the rings,and losened up the carbon,I don't know,but it sure starts easier,and runs so much smoother.I've heard about it on my car forum,but never tried it before.I bought somemore and put it in my 22 year old Corvette.We'll see what happens this week.