Leave your engine mounted. Take a piece of wide masking tape and stretch it accross from the fus. to the center of the head or exhaust or which ever piece you are cutting at that time and mark. Pull back the tape leaving it attached to the fus. Remove the motor and install the cowling. Now pull the tape back over onto the cowling and trace your markings. Works very well. Tape arround the marking on the cowling and use a dremel tool with the bit that cuts with it's side and the tape will keep the fg from chipping. Very easy and works perfect. Give it a try! Good luck.