Don`t think the choke cable idea would work ? there`s a hell of a lot of tension on the lever
Just try pushing it back !
When engine is running pump pushes against it,you can feel mechanism in pump pulsing.
If you let too much tension off lever or let it release too far,van runs crap & white smokes as the lever affects pump timing.
Best to fix original system,when working they are a great set-up
