The Van's Bowden cable (CT A-740) I use for my carb heat control did not have enough friction to keep the carb heat door closed. Ram air pressure would push the door back again. Even my cabin heat Bowden cable would "creep" closed quite quickly through vibration and pressure inside the cowl closing the cabin heat bypass box door.
I fixed the problem by using small "R"-clips instead of the spring to provide more friction against the detents on the cable.
Prize the spring out of the slot in the shaft and move it back down the shaft and slip the "R"-clip onto the shaft with the straight leg in the slot. The straight leg of the "R"-clip had to be sanded down a little to fit snug in the slot in the cable shaft.
I don't know if this mod has been mentioned before. If it has - my apologies for repeating someone else's idea. I hope this tip may be helpful and may save others buying more expensive locking cables.
Jim Talbot
New Zealand
RV7A ZK-JLT
25 hrs flight testing just finished!
Tip: Bowden Cable Friction
Linear Mode
