upgrading?

[legend29]

is it ok to upgrade a scooter little by little and not mess the motor up? I just got another scooter for my brother and i can't afford to upgrade all at once.He wants the performance parts on it as i can afford them like exhaust, BBK,CDI,Carb Clutch etc. but just want to make sure i can do it that way first & every couple weeks i'd add something for him if i can. Also does it matter what order i upgrade in? sorry if this is a dumb question I'm out of my element