The throttle is a direct connection (not recommended) using a
pusher type spring as a return. This is on an H30 using the diaphragm carb...the simple setup worked very well with barely a quarter twist of the hand grip for WOT.
Here's the best picture I could find of it:
I sold it this summer...:sad:
Those tires would do well in the sand but, they'd need a lot more power to
dig in, though. They're Carlisle X-Trac size: 15x5-6.