It seems like the motor sound goes by the load on the motor and not just rpm. The motor sounded like it wound up when you got on it hard, but across your grass you could not have been going all that fast compared to top speed, so motor rpm was not that high I did not know that. When you were on the road I couldn't tell if the motor noise was because of speed (thus motor rpm) or you were heavy on throttle. Anyway, looks really fun. I would have a load of dirt hauled in and make a trail with many corners. Use that dirt to put a berm on all the corners. Maybe some little up and downs with dirt piles here and there. I am not into jumping so I wouldn't go that far. What about any slop or lag when you hit the throttle? If you tried to balance the bike while stopped like a trials rider, and you started to fall over, would you have some instant forward thrust to get you moving to not tip over? For your yard riding, the suspension looked stiff enough from here.