Im thinking of buying a Yamaha Grizzly 700 EFI. How old would I have to be to ride it on the road, and what license/insurance etc. would I need?

i have read this: http://www.direct.gov.uk/en/Motoring/DriverLicensing/WhatCanYouDriveAndYourObligations/DG_4022547

but it says about bhp and kw, and i dont know what bhp the bike has.