[burnin oil]

Basically you get the motor up to temp then raise the RPMs up. From there either dribble water out of a bottle through the carb or use a spray bottle and mist it into the carb. The RPMs will drop off so don't let it stall. It will literally steam clean the piston tops and combustion chambers. This is an old racer trick but be careful as to much water to fast and bad things happen. You can hydro lock the motor if you go nuts. Going slow you can put gallons off water through the carb but it really only takes a 20oz coke bottle to get the job done.