going faster

[new rider]

new to electric carts i have a 99 cc regen II am pretty sure with 500 amp controler hd selinoid and f/r switch 8 inch lift 23 inch tires it goes about 15 mph with good tourqe but i want it faster thinking about 6 to1 gears but dont want to over heat and burn something up o yea stock motor would like to get at least 25 but 35 be great any ideas would be appreciated thanks