So i have the Chinese 49cc and its killing me. every day i feel like the motor hates reving less and less. it started to like to run around 2900 rpm and now it dosent go past 2400 without vibrating everywhere. Like the title says, i wanna buy a new motor. I dont care about cc specifically, i just want something reliable, ported, and faster. Is it possible for the price and what do you guys recommend.