[Masteryota]

No. You need to go bigger on the wheel, or smaller on the clutch to get a 'lower' gear ratio. Seeing as those run small wheels and tires, you may not be able to go bigger without the chain touching the ground. My recommendation is a bigger engine. Keep in mind, you can easily install a throttle stop to limit the speed, but will still have the torque to storm the trenches.

Right now, HF has a sale on the 6.5 for $99. I look at it like this, too much power can be governed, too little power has to be replaced. I would look into a TAV for the 6.5 to really help with the low and top end performance, but a clutch will work for the little one. Remember, the rule for go karts and mini bikes is 6:1 gear ratio. To get this, divide the larger sprocket tooth number by the smaller one. 7:1 or lower will limit the top speed, and will climb walls, if you let it.