Sorry Bski my approach would run you about 100$ including the 12 gage wire, 59$ actuuator, and 5$ toggle switch. The pull cable & spring is well within your allocated budget. You best buy a cheap pair of fish scales and see how much force that choke mechanism requires and provide that info to Lee. The servo might not have enough guts to do the trick. I know all of my lawn equipment has noticable friction in the choke and run levers. Good luck my friend.
