Yup, guys usally switch to the YZ needel at the same time they change the timing. Check thumpertalk.com as I dont know the needel or PNs off hand, there are sevral jetting options available and some like Taffy jetting will give you plenty of power and save fuel, your PJ and main jet is on the pigish side, so are mine, Im at a 40 PJ I think and a 180 Main but Im on WR timing now and I get good milage and I have a 3.3 gallon tank so who cares anyway :) . A 50 PJ sounds kinda fat though.