The red lever on the electric primer valve should be inline with the valve body for the " run " position.---Pointing to the back of the motor.-----Do a complete evaluation of this motor before spending any beer tokens on it.
The red lever on primer valve is in the wrong position.----And what are you using to operate the throttle.-----The small lever or the main lever.-----Perhaps find a manual or a coach on how to operate the motor and the control box.
Use a dial indicator.----Post an accurate measurement of how much movement you get at the flywheel.----Is it 0.003" or 0.013".----No guessing on things like this.
Perhaps throttle plate is opening too early as well.----Retorque cylinder head screws.-----They often loosen up on overheating.----Check thermostat as they are often missing or stuck open.
I have used 1-1/2 plastic pipe cut in half.-----Used to make ribs / stringers.-----The fiberglass is laid over the pipe to give it the shape / strength..----No different than the balsa wood.
