YAMAHA AEROX 50/70 HELP WANT MORE POWER

write guys iv got a Yamaha aerox with these parts fitted
. stage 6 big bore kit
. 19mm TNT carb jetted with open sponge filter
. top racing variator kit with 6 gram rollers
. pm tuning reed valve
. stage 6 exhaust
. pm tuning crank
. polini belt
. malossi clutch

and I want more power what could I have done or what other parts could I get fitted to get more power when I was at italjet uk the bike pulled 9.5 bhp at first but now its at 8.5 I lost 1 bhp after they messed about with the rollers and the guy said its not bad but for that sort of setup they exspect it to be between 10 and 12 bhp

8.5 bhp is just crap lol

so any help guys would be great

thanks