Hi Norm,
Can you just drill a hole in the plastic and hook up the wire to pull the butterfly open for starting.
vice grips would hold the wire on one side for starting then when it starts take the vice grips off.
Another way could be a solenoid and use a 9 volt battery with a switch.
You might be able to use a string and tie the butterfly open then undo the string when it starts.
I used a solenoid once from a car boot release and hooked it to a cable and used a battery.
I've also used the solenoid from car carburetors to hold the throttle open for a quicker idle position when cold.
Cheers
Max.
