I finally found some time to strip down my engine and figure out why it was burning about 1 quart of oil every 20 miles. Actually, getting pulled over by a motorcyle cop today asking why my bike was smoking so much had a little to do with it. No ticket though! To my surprise, it wasn't what I thought it would be, piston, rings, seals. I'm still not 100% sure why it was burning the oil so badly, but here is what I found. The camshaft lobes and rocker arms were comlpetely worn out. The arc on both the exhaust rocker arms were actually worn into a valley, and the cam lobes were pretty flat. But on the good side, the valves, valve guides, piston, and cylinder all looked brand new, and measured well within the service limits. Here is what I measured: Cam lobe Ex-Rt = 1.207 Ex-Lt = 1.178 (ouch) In-Rt = 1.220 In-Lt = 1.215 Ex service limit = 1.220 In service limit = 1.222 This must be why it was burning oil because everything else looked good. But not quite sure why exhuast valves not opening very far would do this. The rest of the parts: Piston = 3.817 (limit = 3.813) cylinder = 3.824 (limit = 3.824) This is a nikasil cylinder Ex-Rt valve stem = .2595 (service limit = .258) guide = .261 (service limit = .261) outter spring = 1.46 (service limit = 1.38) inner spring = 1.30 (service limit = 1.34) ???????????? Ex-Lt valve stem = .2595 guide - .261 outter spring = 1.458 inner spring = 1.30 In-Rt valve stem = .260 (service limit = .257) guide = .261 outter spring = 1.46 inner spring = 1.30 In-Lt valve stem = .260 guide = .261 outter spring = 1.46 inner spring = 1.30 Thats pretty much everything I measured tonight. So one big question is do I need new inner springs? It seems odd that all 4 inner springs are out of the service limit exactly the same. Could the Honda manual have a misprint on the limit for the inner springs? I plan on replacing the cam, cam bearings, rocker arms, valve seals, piston, pin, clips and rings. I'll clean up all the ports and chamber, and lap the valve seats. Though I might take it in and get a valve job since the exhaust seats are pretty pitted. This is my first XR motor I have pulled apart, so if anyone experienced in rebuilding these motors has any comments on the items I measured, or items I plan on replacing, please let me know. And the final question, since I need a new cam and possibly springs, should I stick with the stock ones, or get an aftermarket higher performance one? I could always use more power! Anything else anyone can suggest to do during my rebuild. I don't want to get to involved but if I need to replace the parts anyway. Thanks for all the help. I am looking forward to finally riding a non oil burning, badly smoking XR.