1973 TX650 Valve Clearances - WTF Should They Be? All sources inconsistent.

On the exhaust you want a bit of clatter. If to tight the compression pressure can leak through and burn the valves. To tight intakes can leak like this to, but they won't burn as quick, The cool intake charge cools the intake, The exhaust only sees hot gasses.
Leo
 
I'm running 15w-50 4T oil from castrol. Thinking about it, I would do it warm, so I'd do it to 3/6 while it was warm which would reduce when it cooled. This last time I set it to 3/6 cold.
5twins said:
If you're running the 15-40 diesel oil like many like to do, you will get more top end clatter. I tried it but went back to the 20-50 because of that extra noise.
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The thermal expansion of the aluminum head and camcover increases the valve clearance.

The thermal expansion of the steel valve stem decreases the valve clearance.

During operation they're not at the same temperatures. Ditto while warm, but cooling.

The only time when you can set predictable lash values for these various temps, and not burn your fingers, is while the engine is fully cooled, all parts at the same temp. Engineers know what clearances they want at running temps, and reverse-calculate those for room temps...
 
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