I think 049 engines have probably shed more blood than all other sizes combined. Get a good stout leather glove for flipping the prop. You will be glad you have it. You can control speed a little bit. The needle valve can be rotated out to run the engine as rich as it will run and in to run it as lean as it should be made to run. Maybe you can hook a servo to turn the needle one click at a time. You can also rig a pinch off to kill the engine when you want to.