Jim, i have had a .061 apart on my desk looking at it for about a week now trying to figure the best way to get rid of the supplied carb set-up. The holes in the casting where the venturi mounts are too close to the top to drill any larger to fit a needle valve. I may go with making my own venturi out of nylon to accept a straight bolt thru these holes and then use a Larry Driskil needle valve above. So far, that's my best solution, tho i do run one other wasp with the throttle wired open and it flies okay, just seems hard to get the right needle setting and hold it for a 5 minute flight.. on the other hand it may just need more breaking in, that motor was very tight when brand new and very hard to get started the first couple of times. Ray