I've just been teasing. Look at the first part of my signature; I am somewhat "power crazy". One of my most fun airplanes is a Twist "40" with a Fox .78 on it, and another is my Giant Stik, intended for 30cc, with a 50cc twin on it.

However, if the mixture is set right, an engine shouldn't carbon up running at half throttle. I power all my airplanes to cruise around quite nicely on half throttle, and only use full throttle for certain aerobatic maneuvers. Never had a problem with carbon....

AV8TOR