I have a lot of fun just running my Yerf Dog 3002 around an oval dirt track, but beyond that I haven't had it on any more challenging terrain. It's similar to yours, but mine has no rear suspension. I got it a few years back, cheap, with a worn out Tecumseh and worn out almost everything else, too.
Took off the roll cage, moved the steering to center and the gas to the far right, put on a seat from a lawn tractor. Replaced engine with one Predator 212, at first.
I weigh about 240, so I wanted to run two engines to make it more fun.
I widened the frame 6" from behind the seat to the back, and raised the same area 3" to clear the two engines.
With two Stage 1 Predator 212s, it pulls me around in a very entertaining fashion...