I put a 6" setback jackplate on my Walleye rig and I keep blowing out shift cables. The shift linkage is still working smoothly when the cables aren't attached.
It seems that there's enough slack in the cables, should I try a foot longer cable?
Probably!!
Basically, you should be able to take your cables - route them to the motor, and make a nice loop in front of the motor.
Now, when the motor turns, the cables simply slightly enlarge the loop, or make the loop slightly smaller.
It is important that the loop be reasonably large, so that there aren't any significant bends in the cable.
Obviously, if you wern't having problems before the jack plate, and are now -it would make sense that you need longer cables.
I trust, that you are using hydralic steering, so that you don't have the same problems with your steering cables?
Take care
REW
I have seas star hydraulic steering, that's fine.
I have replace the shift cable twice now in the last year. Funny thing is it's always the shift cable never the throttle cable. The shift linkage isn't bound up. It shifts in and out of gear with little effort when the cable is disconnected.
I'll go with a 15' shift cable and see how that plays out.
Thanks.