Moose Dual Gasser Throttle

Yes, these Dual Gasser throttles can be fit on any machine that has a 7/8" diameter grip area on the handlebars, which covers pretty much every dirt bike ever made. And ProTaper only makes handlebars with a 7/8" diameter grip area. It's only the area between the grips, towards the middle of the bars, that they're fatter at 1-1/8" which you wouldn't be putting this throttle on anyway. You shouldn't have any problems fitting these to your bike.

Yes, you could certainly use this on the Sportsman 400, albeit, you'd have to come up with another way to operate the switch located on the OEM Sportsman 400 throttle assembly. One option, would be to wire up a Moose On/Off Toggle Switch and place it on the handlebar next to the Dual Gasser throttle assembly. With those two items, you'd maintain the functionality of the machine's right-hand controls.

Moose's Dual Gasser Throttles are designed to fit pretty much any ATV out there. There's even a mechanism within the device that allows for the attachment of a wide variety of cables. The included instructions explain exactly how to get it configured to work on just about any machine, included the Kawasaki KFX400.

Yes, you could certainly use this on your Rancher, albeit, you will have to fabricate some brackets to secure the 2x4/4x4 switch assembly that's also attached to the OEM throttle housing. This is due to the fact that there is no provision for attaching it to the dual gasser throttle assembly. So long as you're comfortable with that, or mounting that switch somewhere else, you wouldn't have no problem fitting the throttle to your machine.