Jollyroger:
Take a piece of stiff paper about 3"x 6" and cut out the outline
of cyl. head toward one end of the paper. Slip the opening over
the engine and tape the other end to the fuse. Measure the distance from firewall to BACK of prop mounting plate, then remove motor leaving template in place. Now put cowl in place with nose the same distance as prop plate from firewall. Lay template back over cowl and draw opening. Now you have a matching hole. Make sure you have 2 or 4 deg. right thrust on engine. Cubs will not take off straight without it. Downthrust is trial and error so the plane flys level at half or full throttle.