I have the old model of evolution that has the plug out the top. My big issue is cooling it. with the carb in front, and the muffler to the side i'm having issues of designing some baffles to help Chanel air for cooling. this is on a cub that has opening for air around the dummy cylinders. i have thought of using a PC fan to pull and blow air from the opposite side then the muffler. Going to add some fins at the back of the cowl to help pull the air out of the cowl. running 40 :1 klotzs oil Any suggestions