If you constantly ride round revving the nuts out of the bike then you will need to service it alot more often.
6/12 monthly servicing of a japenese made production bike with high quality manufactured parts and oil is fine. Chinease made poor fitting, poor quality material engine will pretty much need more attention and more often.
Loctite is your best friend as well cos it stops things coming undone and falling off which pitbikes love to do. If you can't afford loctite then nick your mums nail varnish it does a very similar job.