I run mine completely stock, on 10/22 fuel and a 11.5 x 4 prop, and I like the way that it runs, about 4 oz of fuel at 8800-9200 R P M seems to work well, there is always the L A 46 column at the top of the engine set up, and you will see that I have changed from what I used to run, and I found it better to run stock, using a R Smith needle assy..