Wiped lobe and rocker pad on center exhaust. XR's only said it could very well be bad center bearing.Center bearing (non ball bearing surface) on head not in best of shape. Any one sell a cam with center needle braing camshaft? Specs: 89 600r w/10.5 and 630 kit. Just rebuilt with 630 kit new crank and oil pump. Only 8hrs on stock cam and new rockers.