clmooring,

The aft cowl cutout was not only for cooling, but to also make it easier to fit the cowl over the muffler exhaust tubes. I didn't want to cut the tubes in case I ever have a need to reuse this engine/muffler combination. The forward cutout is for the exhaust.

I also cut out the forward starboard indentation on the cowl to direct cooling air over the engine. The port side wasn't cut; I used black trim to create the illusion that it was also open.

Mike