other kinds of 2strokes work like so -=--ehhaust MUST open first
allports should open with a square edge for pulse tuning.
So squareup the opening edge of the crank/carb (both case crank.
then to do cylinder mark the ports edges on the piston top .
Then wih it out mark a line 1/32" down the side of the piston--
scribe a circle at about 1/3 radius tn from the edge.. This will give u an outlie of where to file a trence in the piston top .
A trench changes the ports affecyed also & u can see what yr dooing...slight loss of compression ratio ..more nitro