hey guys new to the forum and new to the atv scene, I picked up a 2002 400ex, its completely stock except for the guy removed the lid, I picked up a white brothers e series muffler today, put it on and drove it, seemed to drive fine but I know a lot of people say to jet the carb if you put a pipe and a lid.. just curious on what I should put in, its still stock jets but I do have a 40 and a 155 that was given to me. will those be ok? i still have the spark arrestor in, i was reading that taking the spark arrestor out could actually make you lose power?