I am probably too late here, but buy a new one- sounds like the used TMEC 200 I got myself back in November; being Chinenginesese bikes, the new ones have things breaking off, too, but at least you start from the beginning rather than buying someone's problems.

Adrenelins are seemingly decent bikes being OEM'd from either Qingqi or Pioneer, which utilize Suzuki-engineered engines; the Suzuki DR 125 engine if you guys have that model, although some differences in design for proprietary reasons.