If it were mine, I would take the cable loose from the throttle valve and slide a couple of layers of shrink tubing (3" long) over the cable.
I would use the smallest diameter shrink tubing that I could fit over the cable (smallest before shrinking).
Before I shrunk the tubing, I would apply a coat of "Seal-All" adhesive over the cable sheath, and make sure that the cable was re-seated in the crimp.
I would shrink one layer of tubing over the crimp...with the crimp in the center of the tubing.
I would then slide the second layer of shrink tubing over the first and shrink it.
I would let it cool completely before handling it.
Using double layers of shrink tubing adds strength and rigidity.

steve