Someone with an air cooled ATC250R might be interested to know that an FL350R cylinder has the same base bolt pattern. It is a 68mm vs 64.4mm stroke. That is not much to have an engine stroked or the cylinder could be machined on top and bottom to retain the shorter stroke.

The intake is also the same mounting. I am using a TRX250R V-Force cage in mine.

 

ive heard of that mod. with the pilot jug too..i also heard its pretty tuff on the crank shuvin that big coconut up and down.. bet it has some kick-**** power tho ;-)