the it 490 i had last year didn,t ping, i think the it,s were a tiny bit detuned from the yz, the 82 yz i had at the same time did a little , both had wiesco,s my k yz490 fitted with a nos top end pings but it doesn,t seem to worry anything ,just gotta be aware of it , the other two k,s have larger piston clearances don,t ping and are faster , and my wr500 which is supposed to be the worst by all accounts just goes hard (has a yed barrell and wr head ) my yz 465 pings a tiny bit as well , i think the it jetting std is a little lean for sustained full open riding , none of mine have had the blend angle machined into the head , the centerport combustion chambers seem to be a little different
