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100-4 rocker assembly question....

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V

Vespa

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Hi,
When my friend and I removed the rocker assembly from his 100-4 cylinder head recently, we noticed four shims that fit between the head itself and each rocker pedestal. Are they suppose to be there? I can't seem to find them listed or shown in the Moss catalogue.

Sincerely,

Paul B.
Bensalem, PA
 
Paul,
I can't say for sure whether the shims should be there. One reason for them would be that if the head has been milled the shims "might" be needed in order to get enough adjustment range on the rocker arm adjusters. I think that a stock head thickness should be around 3.700". If it is significantly thinner than this, say 3.650" or less it has probably been milled.

If the rocker arm adjusters do not have to be backed all of the way out with the shims removed, the shims are probably not needed.
D
 
The shims may have also been installed to get the correct valve geometry after the head was milled, if this is the case.
But, how many people take the time and go through the fiddle of running the valve geometry?
rolleyes.gif

Jeff
 
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