Yamaha p/n 4X7-12159-00-00 used in "large" Viragos from 1981 750 thru 1999 1100, in VStar 1100 from 2000 thru 2009 and in VStar 950 from 2009-2014. They are slightly shorter than stock 650 adjusters and adjust using a hex key.
Yamaha p/n 4X7-12159-00-00 ...
...This valve had gone from .006" to .009" Doesn't look like .003 of wear, could have been an error on my part or a bit of carbon? The others were the same as set to about .001 wider.
... Kind of interesting the tracks look a little longer than those on the stock grind but far from the edges yet. I think there are 3 with the "silver ends" the other exhaust had a regular adjuster...
Your plugs look a bit cold. Shouldnt the ground strap be clean about halway between the tip and threads?
... how does one go about hardening the tips? Is that a heat up and drop in water kind of thing?
... Also, on the regrind of the clutch pushrods, does doing so decrease the adjust-ability of the clutch, since you're removing material?...or is it so minor that it's a non-issue...would "hardening" those also be needed?
...Some pics of the Left exhaust the one that went large on clearance.
I am up against the limits of my point and shoot, using a Nikon S8100 in highest rez in close up mode lens about 3" away, lit by an LED ball cap light, then cropping. On the valve stems, that I have to shoot at an angle, you can see the depth of field is getting down to about 1/8"!
Put another 100 miles on it last night after the pics, sounds good.
At this blow up you can clearly see the track across the tappet end with a detent at both ends. This kinda jives with how the the feeler gauge works, the minimum valve stem/tappet distance is at the back or "cam side".
Thinking on this Ima gonna guess the first dent is the cam profile driving the tappet into the valve stem, the second is valve lift off/return as the cam goes "over the hump"...
... These tappets got about 250 miles on them, about 50 of that at "full tilt" with a lot up and down the gears shifting, at lets say 6K+ (no time to be looking at the tach). The straights were run at 80-90 MPH stock gearing.
I keep meaning to make a mount for a "wiggle gauge" to measure valve clearance directly.
...The new tappet grind evened it out????
... Would like to hear what Jack and Gary Hoos would say on this?