2002 suzuki drz400s. I just bought an older big gun race exhaust system on ebay, trying to find out where to jet the carb at? It is a stock 2002 suzuki drz400, no mods beside simple bolt on, stock airbox, stock cams, stock gearing, no engine work. I was told by big gun to go up 1 main jet size, & go 1/4- 1/2 fuel screw turn. Does sound about right?