I finally found some bolt-on exhaust systems for GY6 mini buggies that could be easily taken apart and put back together without welding to insert some packing to quiet them down but they are expensive...$280 or more for a Hammerhead exhaust I found. Anyway, after doing a lot of searching online I came across this article and decided to leave well enough alone...skip down to the last paragraph...lol
http://www.key-ideas.com/Yerf-Dog-3206-Exhaust.htm