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R12 valve adjustment

Posted: Mon Jan 01, 2018 4:19 pm
by norwaybike
I think the valve adjustment procedure on my R12 is difficult. I have adapted my tools to try enter the nuts better, but it will not be as I wish. Do some of you have any good tips, procedures or tricks to make this job easier?

valve adjustment

Posted: Tue Jan 02, 2018 6:00 am
by Bigsieuk
There are a number of ways posted here. As space is so tight when the valves are closed, I usually check the gap when the valve is closed, then rotate the engine and adjust when the valve is open as it gives more space and then check again when the valve is closed. It can take an number of tries to get it correct but its easier than trying to get the spanners in the small space.

R12 valve tools

Posted: Wed Jan 03, 2018 1:08 pm
by mdunn
Having the right tools makes it easier but its still a bitch. One of the most lame designs ever for BMW if you ask me.

I generally do it as Bigsieuk

Posted: Wed Jan 03, 2018 2:01 pm
by Bruce Frey
I generally do it as Bigsieuk does. If you measure the gap and know how much adjustment is needed, you can calculate how far to turn the adjuster by knowing the thread pitch (I have forgotten what it is, however). e.g.,if the thread pitch is 1.0mm, then 1/4 turn is 0.25mm. It will probably take a couple of tries, but it works.

Fabricating a set of tools that fit is really, really helpful.



Posted: Thu Jan 04, 2018 6:00 am
by Bigsieuk

Does anyone sell those types of spanners?



John, NO, unfortunately not.

Posted: Wed Jan 10, 2018 10:03 am
by mdunn

NO, unfortunately not. I have a casting to make them and I plan on it soon.


John,NO, unfortunately not.

Posted: Wed Jan 10, 2018 10:05 am
by mdunn

In time I will have them....

I picked up a set on Ebay

Posted: Wed Jan 10, 2018 11:31 am
by Beemer54
I picked up a set on Ebay about a year ago. As Mike says - they help a bit but it's still a ridiculously fiddly job - they're still too thick. Your way works better.
My final solution was to nag friends to look in their rubbish drawers to see if they'd got any of those awful, thin multi-spanners that tend to come with new lawnmowers, strimmers and the like. I was able to cut these up and bend them to the correct shape. Because they're so thin they make life much easier. They wouldn't be suitable for anything that was really tight but they're perfectly adequate to tighten tappets.

Bicycle tools also make a

Posted: Thu Jan 11, 2018 10:44 pm
by Bruce Frey
Bicycle tools also make a good starting point. Thin and relatively inexpensive.


As Bruce says, you can buy

Posted: Sun Jan 14, 2018 11:24 am
by Darryl.Richman
As Bruce says, you can buy "spindle" or "hub" wrenches at a bicycle shop. They are stamped steel, but strong enough to lock the adjustment. You will have to grind material off them before they will fit, and you can bend them with a propane torch and a vise or vise grips.

As everyone here has confirmed, adjusting the valves is a PITA no matter how you try. I've run my R52 on the Cannonball a couple times now and had to adjust valves on the side of the road.

I've tried both methods, and both are slow and annoying. If you don't have the right tools, you can really only do it by measuring with the valves closed and adjusting with the valves open. With usable tools, I think it can be done a bit quicker with the valves always closed.

BMW could have easily designed this so it could be done easily with regular tools. ~X(