Tim does the same: (He actually did his first. But he went through the initial steps before I knew he was even starting on it, so I missed photographing his initial steps.)
While we were are at it, we must also cut clearance for the glow igniter. On a YS engine, this is off-center, as well as slanted to the rear. I made alignment marks on the cowl, and used them to mark crosshairs for a clearance hole.
Next, I sand away the material in-between the two cut-outs and have a shape I am satisfied will be relatively user-friendly.
Fit is good, but the shape in the front, is still not symmetrical enough for me.
So again, I outline more to be sanded and shaped, better.