running rich

May 4, 2006
hello all, i am new to this site and have a 73 commando 850 roadster. i have been having a problem with running rich on one side. the bike was from 3500' elevation and i live at 5500'. she runs beautiful until the right side plug fouls with a sooty black. it does not look like oil. so far i have changed the main jets from 260 to 240. although not fouling as fast, it still seems to get the plug pretty black. the other plug looks okay. the needle is in the top position so i left it there. this bike has 10,000 miles on it and feels real fresh and runs strong. any ideals out there. cheers, jerome