Thanks Craig!Welcome to Miniriders,
I spotted this bike on Gumtree yesterday.
Suzuki thumpster 125 | Motorcycles | Gumtree Australia Fremantle Area - O'Connor | 1066118930
There's nothing wrong with a cheap pit bike, one of our members Cordogs' $100 bike won our last Fifty of the Month competition.
Check out Coreys' build thread- http://www.miniriders.com/china-builds/40198-cordogs-100-china.html
Your bike is based on a CRF50, and uses the same tank, plastics and seat.
The engine is an early Lifan 125 going by the shape of the clutch cover, most parts are pretty easy to source off ebay etc
The BBT markings on the engine might have been a pit bike dealer from a few years ago?
The exhaust flange's don't always sit right up flush to the head, they can have up to about an 8mm gap there depending on what type of gasket and how tight it's done up etc
That old oil looks well and truly past it's use by date too! lol