Valve adjustment temp

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CVA-42
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Valve adjustment temp

Post by CVA-42 » Mon Sep 23, 2013 10:43 am

One of my riding buddies wants to begin performing basic servicing on his hexhead GS himself. I told him to bring the bike over to my garage and we would do it together. I've always adjusted valves on my bikes from /2's to hexheads when they're dead cold, i.e., after the bike sits overnight. How cold do the valves actually have to be before adjustment? Can we get away with letting the bike sit for a couple of hours, maybe with fans on it, or does it really need to sit overnight?

Major Softie
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Re: Valve adjustment temp

Post by Major Softie » Mon Sep 23, 2013 1:40 pm

Great question: how cold is cold?

I would think once it's comfortable to handle, it's cool enough. The valve parts will cool a lot faster with the valve cover off.
MS - out

CVA-42
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Re: Valve adjustment temp

Post by CVA-42 » Mon Sep 23, 2013 4:14 pm

Major Softie wrote:Great question: how cold is cold?

I would think once it's comfortable to handle, it's cool enough. The valve parts will cool a lot faster with the valve cover off.
According to a BMW tech who responded when I posed this question on another forum, the BMW spec for "cold" in this case is 95 degrees F. I've seen valves adjusted at tech days after cooling with fans and valve covers off. Just have never been sure if this is the right thing to do. Prolly right, though, Major...if it's comfortable to handle, it should be cool enough.

jimmyg
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Re: Valve adjustment temp

Post by jimmyg » Wed Oct 07, 2015 3:12 pm

just have him ride it over and place a couple of fans on each cylinder. Within 30 min. it will be cold enough.

I do it all the time when my buddies ride their bikes over.

jimmyg

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Steve in Golden
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Re: Valve adjustment temp

Post by Steve in Golden » Wed Oct 07, 2015 3:27 pm

Duane would probably say it doesn't make any difference, cold or hot it's all the same.

I agree that after it's cooled off for a while, it's good enough.

Major Softie
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Re: Valve adjustment temp

Post by Major Softie » Wed Oct 07, 2015 4:32 pm

Steve in Golden wrote:Duane would probably say it doesn't make any difference, cold or hot it's all the same.

I agree that after it's cooled off for a while, it's good enough.
Duane might say that about an Airhead, but that's not what we're talking about. Different designs change more, less, or not at all, depending on the design. I have no idea if a hexhead changes much with temp or not.

When I replaced the head gaskets on my Oilhead (leaking oil), since the new design gaskets are a different thickness, I was really surprised to find that the valve adjustment was unchanged when I got through buttoning it up. Then I realized "DOH!", the cams, pushrods, and valves were all removed together untouched, so it would have been really weird if something HAD changed. :oops:
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The Veg
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Re: Valve adjustment temp

Post by The Veg » Fri Nov 27, 2015 7:47 pm

Being a hexhead-guy, I really should check in here more often.

I'd say I agree with the general consensus that it ain't critical; do it at any comfortable temperature. That said, I never adjusted my former hexhead very soon after riding (good riding-day = do maintenance some other time unless the need is strong/time-sensitive). My current hexhead is gonna get its adjustment very soon.
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