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what size shim for new head set-up is typical?

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very new at dirt bikes much less working on them. I am going to install all new head except buckets. what size shim am I expected to use on a new set up? is it just trial and error until I reach spec? thx.

Edited by brandonshepherd

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On the IN side I usually end up around: 180 - 200

On the OUT side around 240 - 260 

 

But I'm not sure that this is typical, it's what I end up after valve replacement.

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It's going to be tial, but never error. lol. just start with the shims you have , as long as there not zero'd out and measure your clearance and calculate what you need.

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What exactly does it mean when people say "zeroed"? Does that mean that the shim required to get lash in spec is below the minimum available, 1.20 IIRC

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no, it means the valve clearance is at zero or holding the valve open, should try a much smaller shim, or if your cheap and can flat grind the shim, grind it thinner then measure to calculate which shim you will need to buy.

Sorry MD, I was writing while you posted.

Edited by bucket list

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I know the answer is going to be it depends but when the valves start moving is it generally seat wear, valve contact wear or stem stretch?

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THANKS!

In that case is there any harm in nursing a few more hours out of the head after reshimming? How many times is too many? I assume you don't want to be at the small side of the shims for too long.

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