Bought a 2003 gt 125, never run probably, and when I took for mot, the mechanic told me the engin wasn't standerd , it had had a larger cc cylinder on it as he could tell becouse it was blue. I can't get this bike to run probably, pinking, running on, back firing, stalling. Thier is also an after market exhaust pipe and a free flowing air filter. I've made the mixture richer, I'm about 3.5 turns out.
Any idea's as I've always had sports bikes.
Thanks
Martyn