It took me a long time to get my throttle right....although it still needs work, pedal is still quite light.
The cam on the throttle required a LOT of travel in order to go from closed to fully open. I ended up having to change the cam on the throttle itself as well.
There are places here in the UK that can make any cable you need, and quite cheap too.
www.speedycables.co.uk
Just in case there are any other cables required. ( they made my speedo cable for example )