the 03 had a bad needle in it,for 04 it was redesigned and to tell the truth works dang near to perfect(even with the TPS connected,which does reduce predetonation immensly). i've heard this complaint about the JD kit too many times to keep track of ! i've ridden a 03 wr450 with the JD needle and complained about the same thing. the 05 needle is unadjustable and probly different taper also. the 04 needle fits the 05's(and is adjustable) i know because 'dan lorenze' has one in his 05 and i've yet to see him complain with this issue. try the 04 needle;04 good. probly not that much$ either dan probly has the part #,how'bout it dan?