Originally Posted by Venice Motor Bikes
DOOOOOD... you need lots of air flowing over the engine or it will burn up!
(that's why they're called 'air cooled')
Take a look at this picture...you'll see that the air gets thru plenty, straight thru and out the back. I have ridden this at the end of summer when we had some warm days and I can leave this thing idling for a while without heat buildup. I crank the throttle full doing full speed for long distance and no heat buildup other than usual. These motors aren't as fragile to temperature as you think. I formed the panels to have a inward "c" type flanges top and bottom for rigidity.