Cam lobe low spot and grove in rocker. CRAP!

[Whiterabbit]

Hey all,
Picked up a '74 in ruff shape so I'm ripping it apart to make it into a bobber/brat.
Must have had a wicked head gasket leak. Lots of caked on oil on the cyl.
So I start busting it down to hopefully just do a head and cyl gasket job, maybe lap the valves and new seals too. Light rebuild.
WRONG. BIG grove perpendicular on one cam lobe and a grove on the rocker. How the hell...
So will any XS650 cam swap in or just one from a 74?
Thanks.

 

[gggGary]

74 makes it easy, anything 74 up will swap in.

Gotta see a pic.

 

[Brian902]

Years ago saw that kind of wear, owner forgot to install the gear on the oil pump.

Probably not your problem.

But you do have a oiling problem.

Check pump and oil lines/passages, something is blocked.

This has some info on how the oil gets up there.
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[Whiterabbit]

Yea, gonn'a blow out that oil line real good. Was right side exhaust lobe and rocker. Left side looks great and here's the odd thing. Almost no buildup on the pistons and combustion chambers plus I still see faint crosshatch pattern on the cyl bores! Piston tops have no oversize markings. You can see the arrow and a faint 16 on the piston domes, this from an engine that had 33,000+ on the odometer. I'll mic the bores at the shop tomorrow.
Never worked on a Yamaha so forgive the nubie questions. Oh, I have a 76 from the buy one get one free deal too! Might Cafe that one.

 

[gggGary]

if the oil flow is good the pump will send a lot of oil out the front fitting where the oil tube was at kicking or e-start speeds. Micheal Morse tells of a racer that went a season with no head lube. cylinders are basically splash lube, like a lawnmower. LOL

Would like to see a pic I'm going to guess a valve adjuster backed out or something along that line where a loose part gouged the cam.