Yes it will work for your 5hp -no problem! If he still has the CVT you'll need :
BMI.Com Part # 03191A
http://www.ebay.com/itm/ws/eBayISAPI...:B:WNA:US:1123
(this part bolts under your engine and holds the driven unit- then you'll need a jackshaft designed for your driven (a snap ring slot & female threads at one end and a 1/4" keyway) & sprocket that matches your axle sprocket & jackshaft dia..
This link will explain how it works and what type to use:
http://www.*****************/asymapp.htm