general questions about briggs

my 14 hp briggs powered riding mower quit starting about a yr ago, i have pulled the starter and solenoid for it and started cleaning off the grease , it has sat for about 7 months or so, and i am embarking on a new endeavor of transforming my ordinary mower into an extraordinary riding machine. however i need some specs,so i know how i can improve both power and speed, i was wondering if anybody here knew how many cfm a stock carb is on a 14hp, also how do you remove the drive pully.

any help is very appreciated
Thanks - Matt