I am nearing the end of my Sig 4 Star 60 build and test fitted the engine and throttle linkage cable from the carb arm on the engine to the servo arm.

The cable is flexible and incased in a plastic sleeve.

The problem is that when I push the throttle up, the flexible cable bows(binds) instead of pushing the cable and opening the throttle. Any ideas to stiffen the cable at the servo end?

The carb barrel on my Evolution 15cc gas engine is also stiff and contributing to the problem. The first 25% of travel to open the barrel is tight and I can't seem to loosen it up enough to stop the flexing (binding) of the throttle cable.

Tried a couple drops of oil and repeatedly working it, but that did not seem to help. Is there a way to get that carb barrel loosened up?

I attached some pics. I would like to make that cable shroud in pic#3 more rigid too because it bends into the bottom of the muffler when the throttle is opened.