hi, i bought my 80cc bikeberry kit about two years ago, and still have original everything except rear wheels. i was wondering if there was some sort of maintenance i should be preforming after this long. Because i havent done anything more then fill the tank and grease the chain. The motor is well broken in and it flys like **** now, i love it <3. I really yern for a higher top speed though. Advice on the quickest way to do that too? Thankyou!