Well love my Yellow 96, but it doesn't have a growling sound in the lower gears. I'd check belt tension first as the belt being tight could make a different sound. Special tool is in the tool punch behind the chrome locking cover on the RH side (sitting on the bike). If no tool you shouuld be able to twist the belt 90 degrees mid run will little effort. Other than that check the location of other members and see if theirs make the same noise as it is just normal. Welcome to the club, Max