Now I have to play detective. I'm really not sure if that annoying "clank clank" noise is from the long rocker arm or not. EDIT--I think perhaps its just the nature of the beast. That desk the engine is running on is hollow, and it amplifies all the sounds like a drum. Since I have everything out to run my engines, I have put away the Odds and Ends and am now running my Kerzel on the same desk, and its twice as noisy as it is when its running on my heavy work bench out in the main garage.--I'm not going to worry about it!!