WW2 Ace,
I use the same ball connecters on my BiPlane. I don't have it on the throttle linkage. I have them my Great Planes Pitts to connect the upper ailerons to the lower ailerons. Been flying it that way for 2 years. It makes the set up a lot simpler at the field and I haven't had any problems at all. The lingage rods are 4/40 and the pin that goes through the control horn is 2/56. It would have to shear the pin in order to fail. Of course I don't think that the ailerons have as much vibration as a direct connection to the carb. I don't think I'd be scared to try it. What's going to happen if it should fail, shut down the engine?? Just thought you'd like to know. Bill