I have to agree. I have never bench run an engine. I always put it on the plane and do as apexpert stated. I run a tank of fuel through it really rich and then fly it. I always keep all my engines running on the rich side anyway and I have never missed. I do this with all my engines, both 2 and 4 cycle. I am sure that there are those that will tell you that I am nut's, however it has worked for 30 plus years. Good Luck, Dave