Hi, I'm following Sticky's instruction on cleaning my carb. When I pulled the carbs off the intake I noticed one of the butterfly were dark or burnt from the obvious backfireing the bike was doing. I also noticed the on that same carb the "Pilot/Slow Jet Adjustment Screw" has a slit cut in the "D" shaped head that the PO(s) did to adjust the jet since he probably didn't have the "D" shaped tool for adjustments. When I unscrewed that one I could see the needle end was not quite as smooth and had very fine spiral marks on it, much different from the other needles on the jet.

My question is; do you think this jet should be replaced or will it be okay to put back in the carb?? Could this jet have affected the bikes performance? Thanks.