Howdy gents, I'll try to keep this a short as possible: anybody who's checked and set their own valve adjustment, I need your help.
I followed the Yammy repair manual's valve adjustment guide from 650ccnd
to the letter. First problem: the repair manual says to find TDC by aligning both the camshaft sprocket with it's mark on the cylinder head (the dot and pointer) AND the T/I on the rotor with the the AC magneto cover (the T/I mark and the notch), but I cannot do both
; when one is aligned, the other is approximately 10-25° off! When the head is aligned, the rotor is 25° off to clockwise; if I align the TI/I and the notch on the rotor, the head is off by around 10° to counterclockwise!
Assuming the camshaft sprocket on the head was more important, I went with that. With hesitation, I continued.
After taking my first measurements, I found that both the intake and exhaust valves were within spec (intake was right on the minimum at .07 mm, exhaust was .14 mm, both within tolerances). I then rotated the crankshaft through 3 full rotations in order to recheck my measurements, expecting no difference, since I hadn't made any adjustments; THIS time the intake was at .05 mm (.02mm out of true) and the exhaust was at .15mm!
My measurements are good, I checked several times, both times, using the "go/no go" method. My feeler gauges are good; I borrowed a second set just to be sure. Both times I (rather comically) stuck my eyeball three inches from the sprocket and lined up the pointer with the center of the dot to the absolute stupid best of my ability, probably accurate to a half-mm or better.
What could be causing these two phenomenon? Are they related? Am I incompetent? Is this a manufacturer's defect, or a parts failure? Do I need to do something different? As is, I'm inclined to simply put the head covers back on and forget I ever mucked with it. While I'm just an amateur, I just removed, rebuilt and reinstalled both carbs and greased the rear drive splines without a single peep of trouble, and after those confidence builders, I'm kinda shocked that things have gone sour so quickly. The manual is not helping me here. Any suggestions?