Most of the info I have seen on break in for this type of engine recommends wide open for at least one tank of fuel. Does this mean the instant you set the starter down you nail it and dont let off? Im always a little hesitant to run any engine wide open until there is a little heat in the motor. Aluminum expands faster than brass so I would think the piston would grow faster than the cylinder and cause problems. Most of my experience comes from motorcycle engines so maybe it doesnt apply to glow.