This is probably a dumb idea and I don't claim to know a lot about electronics but I've messed around with remote control planes some and I got to thinking about rigging a servo for the throttle on my MB 45 and get rid of the cable or linkage woes. I know it could add a whole new set of problems but just wondering if anyone has tried this. The main thing I'm not sure how you could make work is how to link it to a throttle handle so if you hit a stump or log and lose grip it lets off the throttle. Anyway, it may not even be possible but just wanted to bounce it off you guys. See video below for one application

In theory, you could set it up just like a RC vehicle if you could find the right parts. Mount the servo on the existing engine throttle plate. Rig up a linkage to operate the throttle. Wireless would be a poor idea. Run some conductors up to your tiller arm, and add the appropriate spring loaded switch, with power being fed from a keyed ignition source.

Spring loaded lever just like rc control box.

If I'm thinking along the same terms as the robots I work on at work, you would need some sort of an encoder to tell the servo motor how much throttle you would actually be giving it. Which in turn would also mean that if it ever got off 0 it would have to be reset. But I can very likely be wrong. I've never dug into rc servos. Just the 12k lb robot servos at work.

Look up some aftermarket "drive-by-wire" setups for cars.