Originally Posted by Kevlarr
Can't vouch for any of the sellers there but with your budget you can always check ebay for the 49cc kits.
Yes I was thinking about that and the exhaust on this model
LTD 49CC BICYCLE GAS MOTOR ENGINE KIT MOTORIZED BIKE 2L - eBay (item 290342667282 end time Sep-22-09 08:29:48 PDT)
says "hush" exhaust and I'm mostly worried about the loudness of my bike.