I'm not sure what is happening to me here, but it bothers me. I have a ModelTech Magic 300L. I've made about a dozen successful flights and it has all trimmed out very well. But there is one thing that disturbs me. When I go to start up the engine the servos jitter when I connect the starter igniter. They jitter a little whenever I touch the engine with anything metal. I don't see any jitter any other time and haven't had any problems in flight, but I don't know what is happening. Has anyone seen this before?

Nothing to worry about. Giving a bit of RF noise because of the metal to metal contact. It's the reason not to use a metal clevis on a metal throttle arm or any metal to metal contact on the plane.

All of the push rods are metal, but I have all nylon clevises. I hadn't thought about the metal push rods do these interfere with the radio?

sometimes, but in your case I wouldn't worry.as Flypaper 2 explained.