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Rocker shaft

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David R

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Has anyone shimmed the rocker shaft so it has less play and I want toget rid of the 'Chink Chink " sound. I can fit an .008" feeler gauge in there. that is .2mm. Where do I get shims?

I did it on my air head.

Just a note, they do need adjusting frequently.

David
 
Also, I took it apart at 60*C and valves got tighter as it came down to the 35*c or cooler spec.
 
? Sorry I don't get it ... the valves adjust with an adjustment bolt ... no shimming like on an old Jaguar ...
 
Rocker shafts . Right side exhaust has .010" clearance, intake has .007"

This makes noise. An 18 x 21 mm x.005' shimm would quiet it down. Going to the Beemer Barn today to see of he has anything.

David.
 
I am drawing a complete blank here ... could you take the pic here and annotate it where you are taking about?

Right Side Stripped.jpg

Really curious :D ... the rocker shafts on mine are clamped down .. they don't move at all .. or they better not! ... now the rocker arms do .. are you talking about the endplay in the rocker arms?
 
Ahhh ... now that makes sense .. thanks!

I will have to check that on mine ... next time I have the valve covers off.
 
Be careful with shimming the clearances too close as premature wear will occur.

This post is oddly topical for me, as I just finished adjusting valves on wifey's 76' Honda CB500t.

On the Honda, the factory calls for 0.03mm cold, which if you've looked at 0.03mm on your feeler gauges is CRAZY thin. Owners have flipped Honda the bird and agreed that 0.05 - 0.06mm is more acceptable, as this reduces wear over time, courtesy of allowing something called "oil" to pass between the rocker arm and the valve end ;) .

Point I'm making is that gap is GOOD for rocker arms. Can you get away with a closer clearance? I don't see why not, but keep an eagle eye out for wear pattern.

Mike
 
Keehn said:
Be careful with shimming the clearances too close as premature wear will occur.

This post is oddly topical for me, as I just finished adjusting valves on wifey's 76' Honda CB500t.

On the Honda, the factory calls for 0.03mm cold, which if you've looked at 0.03mm on your feeler gauges is CRAZY thin. Owners have flipped Honda the bird and agreed that 0.05 - 0.06mm is more acceptable, as this reduces wear over time, courtesy of allowing something called "oil" to pass between the rocker arm and the valve end ;) .

Point I'm making is that gap is GOOD for rocker arms. Can you get away with a closer clearance? I don't see why not, but keep an eagle eye out for wear pattern.

Mike
Click to expand...
Agreed ... shimmed it to close on a Shovel before ... the results were less than desirable ...
 
I too have squeezed the rocker shaft on an airhead and caused the rocker to stick.

After a trip to the BEEMER BARNN, I left with what he had for shimms. He knew just what I was talking about.
The smallest were .007". I saw as big as .018". I left with 4 of the smallest.

I put one on top of the right exhaust. It does not fit, so I put it on the bottom below the spacer.

Before I could fit a .010" on the right exhaust rocker. Now I can feel a teeny bit of play and see it with the oil where the shaft meets. I can move the intake one up and down on the shaft and make a chink chink noise. Not the exhaust.

I can only fit a .007" feeler gauge in the rest, so I think I need some .004".

It is defiantly quieter on the right.

I did this cold. Then went for a 20 minute ride. I pulled it apart hot. About the same clearance as cold.

I will get back to you with BMW part numbers.

David
 
Just my 2¢ on that, .004" is really really thin and on a 'Sovelhead' .01 - .02" play is considered average and I really doubt that you can hear a difference over the racket that these solid cam followers make on the R18 ... and consider this, if this veeeeery thin shim should get rubbed through and disintegrate you will have shimstock debris floating around your engine and hat would be really bad ... as I said, just my 2¢ on this, your bike your call ;)
 
I put a BMW rocker shaft shim in a BMW. Not sweating it. :)
The shim is below the original spacer (bearing) which only comes in one size.

The ends of the rocker were polished most of the way around, like it was a really good fit. 22,000 miles, worn in well.

The more my hearing deteriorates, the more I love this bike.
David


Just a side note. I took the bike to the dealer I bought it.

The service manager said "I'm from Harley Davidson. Did you know if you modify the air cleaner on a Harley you can hear the valves?"

They kept it over night and said there is nothing wrong with it. No invoice, no bill, no nothing, just see ya later.
 
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