Tried making too tight of a bend. Kinked Tubing. Note either tubing should be heated, then bent. Or use a larger radius (kinked with a nice 1" radius, 2" recommended). A little lathe work, and new tube will take care of it.
One Bearhawk (not a QB Kit) discovered undersized push rod lead to flutter. Not good. So I'm a bit sensitive about this.
Hindsight.... some 3/8" tubing, end smashed flat, drill with #30 drill and cleco. Easy to get the bend just right, THEN bend 4130 push rod. Live and learn.
The rudder cable to pedal bracket needs an adaptor.