[sho305]

I would try a cut sheave with a umax spring, preload more than stock. I would pop the primary and make a sleeve or bushing or spacer to limit how much it closes, you will have to experiment with this. I would set the factory speed governor low as you want, you still get full power under that speed. Far as engine braking I just don't think it would give you much even if you did get it to stay in gear, its a 10hp engine. I would look at disk brakes or better yet front brakes.

You might run up to a 1.25 belt but have to be careful they do not always engage properly. A longer belt usually hurts low speed performance, a shorter belt can help a little but basically does the same thing as a wider belt. You need to be careful because changing the belt size can cause you to not reach the lowest gear ratio. With a cut sheave you might be able to run longer belt but doubt it is that much difference, unless cut sheave makes the belt tight on the clutches. If the clutches are worn a slightly wider belt can work better.

The cut sheave is the only thing that will give you a lower (higher number) ratio I know of, aside from gear changes, and you need the belt lowest in primary that does not engage and half out of the secondary to get it. Make sure the tension cable is working if it has one. *Remember a wider belt goes higher in the secondary=lower gear (that also what a cut sheave does) but too wide will drag on the primary and make the cart creep on the starter. Find the best fit.