If that's a Jett on a Mach Racer, be very careful. I had 2, one with a Magnum .52XLS with a Rossi short pipe. I got flutter on the elevons and broke the control system. My next one had an OS .50SX with a Jett tuned muffler, 9-7 prop. I used titanium pushrods and Sulliven metal control horns.

My recommendation: Do not trust the stock plastic control horns or servo arms on a high speed plane. Consider at least 4040 pushrods.