RE: Advice on ducting/baffling
I am in the process of baffling my Yak 54 50cc.
What you have done is about what I am trying to accomplish.
I planed on putting some (4-5) louvers behind the head of the engine. In my Yak 54, that would be in the radiator box of the cowl. The air passing by the louvers will create a vacuum in the cowl and should remove heat from the crankcase also.
How are you going to attach the ducting?
Greg