There is very little different between a manual clutch and auto clutch. The hand lever does the disengaging and engageing in a manual...and the foot shift does the engageing and disengageing on an auto. The clutch basket and plates are the same, all that differs is the method of engagement.The bad thing about an auto clutch, is there isnt a way to slip it...its either engaged or not, its not possible to be inbetween and slip it.
When you first worded the question...i was wondering why you would want a hand clutch...now I know, its because you want to slip it.
One other thing standing in the way, of a manual conversion...somehow the centrifical clutch needs to be locked...or eliminated.
The one down side to a fully manual clutch, is the motor can stall, and usually at the worst time...however with an auto clutch, it wont stall, even if youre in 5th gear and trying to start out from a stop.

 

Thats true it CAN stall, but if you know what your doing, then it won't stall.

 

Also, do you think it would improve the power of the rancher and wake it up or would it probally be the same power wise?

 

The horsepower is the same with or with out a manual or auto clutch. Your only advantage, would being able to hold the revs higher at a slower speed. Which is somewhat self defeating on a honda utility quad. Those motors are designed from the beginning to produce low end torque, and very little upper rpm horsepower. Im thinking if this is your style of riding...you should get a 300ex or other sporty, that has a manual clutch, and is designed to rev.
If you need more power at lower speeds, why not just hold on to a lower gear longer? Theres no chance of overrevving the motor, they have a rev limiter, and the intake is so restrictive (because thats the best way to get low rpm torque), that it cant rev high enough to hurt itself.