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Shim size for valve adjustment


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Does anybody know if 8.9 mm is the right size shim to perform the valve adjustment on my R1250RS?

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Hi so if I purchase the 8.90 Diameter Wiesco kit that's the right one?Sorry just want to be sure.Dennis

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35 minutes ago, Dennisemanuel said:

Hi so if I purchase the 8.90 Diameter Wiesco kit that's the right one?Sorry just want to be sure.Dennis

 The kit will have a variety of shims of the correct diameter that will fit your bike, but there is no guarantee that you will have the shims of the proper thickness.  However, the odds are good that if you buy the kit, you will get shims that will enable you to adjust your valves somewhere within the desired range.



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The Wiseco VSK4 kit you get may or may not have the sizes of the shims you want/need to adjust the valve clearance to the target value YOU are trying to achieve.

Over the weekend I saw 2 new Wiseco VSK4 kits that had not been used, so had an original inventory.  There are 23 different sizes provided in the kit with 3 each of those sizes.

The kit has shims starting at 1.72mm and has a 0.04mm spacing up to 2.60mm.  Of those sizes, I find that the most common sizes used on our R1200 and R1250 bikes are in the range of 2.00 thru 2.40mm.

That means that you only really use 11 sizes of the 23 sizes provided in the kit, and the other 12 sizes you get are extras that I almost never use...so I just pile those that are above and below the most common sizes in a single compartment.

(see image below)


I have augmented my Wiseco VSK4 kit with additional Pro-X Shim Refill packs from OEMCycle.com to fill in the somewhat wide 0.04mm spacing with all the most common sizes that now give me a 0.02mm spacing set of shims in the full range of the most common sizes. (highlighted in yellow in the first image below)  The part number format for the 5 Shim refill packs that I use is:  29.890202  Use this format in the Part number search field to find the correct 5 shim refill kit.  The last 3 digits are the shim thickness that I want and I just change that number to find other sizes that I need...so the next one I would order to augment the Wiseco kit would be 29.890206 since the Wiseco kit already has a 2.04mm shim I'm just filling in the sizes in between what the kit has.


This is really only necessary for someone like me that does Cam Timing and Valve Clearance Checks frequently.  So far, I've done about 110 of these checks and have experience with what shims get used the most.


It gets to be very costly to do this for just your own bike, so I recommend that you do the calculations for yourself to determine if you want to buy this much inventory.  It might make more sense if you were to buy tools and shims for several of your friends or a local club.


If you buy the Wiseco kit on Amazon for about $60 and then buy these extra shim kits for the most common sizes in between the 0.04mm spacing you then would need about 10 of the 5 shim refill packs from OEMCycle...at about $9.20 each.

Now you are up to almost $160 with shipping!


If you were to order the shims from a BMW dealer to do the valve clearance adjustment, they are about $10 per shim...and on average, I change out about 6 of the 8 total shims to get a valve check job that I do to MY target setting.

When I do a valve clearance check, I used to target the mathematical middle of the range of values for the R1200/R1250.  The range for the INT is 0.10-0.17mm and EXH 0.34-0.41mm, making the exact middle INT 0.135mm and EXH 0.375mm.  I explain what my NEW TARGET is now in more detail (below).


It would be much less expensive to do a valve clearance check, record your clearances, take the cams out to measure your existing shims and order the EXACT shims from BMW you think you need for your bike during its first 12k service.  But, I've found that a little over 50% of the time, when working with the shims, the recheck clearance after installing new shims doesn't meet my target.  I need to take it all apart again to exchange a shim or 2 because I didn't hit the target value I wanted in the first place.  I think there is some operator error and lots of judgement in the perception of what drag you get on your feeler gauges used to determine what your original clearance and new clearances are!  


If you took your bike apart to get a baseline of your valve clearances and all your shim thicknesses, then ordered just the shims that you think you need, you will often have a bit of a wait for them to arrive.  Then, you may find that a couple of the new shims are not going to get you to the TARGET value you were looking for....so, you just order new shims from BMW and either wait to finish the job until they arrive, or redo all your work when they arrive if you put your bike back together to keep riding.  That is why I have all of the shims in stock.


As you can see on the included worksheet below, my NEW TARGET clearance for valves is INT 0.12mm and EXH 0.36mm...somewhat tighter than the mathematical center, but not too close to the tighter limit.

This gives a quieter running engine and in my experience with following the clearance change on engines over the miles, more distance until you might need to make a change.

I have found that the valve clearance tends to open up slightly rather than tighten up, giving a long, long time before you would need to change anything in the valve train.


I have a lot of $$$ wrapped up in my Shim Kit, and it only makes sense because I do soooooo many Cam Timing and Valve Clearance checks...don't feel compelled to go down this road just because I do it this way!

If you want a PDF version of the R1200/R1250 Cam Timing and Valve Clearance Worksheet to print out, you can request it from me on my Google Drive and I will reply with access...it's a 2 step process, so please be patient and check your Junk folder on your mail program as it has been reported to go there frequently.  Link to R1200/R12500 Cam and Valve Clearance Worksheet

PM me with any questions about any of this.





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  • 1 month later...

Hi, I’m very new to this forum, and recently went from a 2006 R1200RT to a 2018 wet head. I’ve read this and various threads related to valve adjustments, shims and shim kits. Reminds me of when I used remove camshafts and bucket tappet shims to adjust valves on my late 60’s-mid 70’s Alfa Romeos.
My question is what members have found related to quality of aftermarket shims; the material, machining accuracy & uniformity. Other than OEM BMW shims available from various dealers at $9+ ea, I’ve only read about and found Wiseco VSK4, Pro-X Shim, Moose branded (Wiseco) and Hot Cams sourced from eBay, Amazon, etc. 

A fair number of reviews mention issues due to quality and inconsistency. Any thoughts are appreciated. Thanks.

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Hi and thanks for the reply and info. Good option for myself and anyone looking for a quality shim kit for our bikes.
Best regards,


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  • 1 month later...

Boxflyer, good to know I'm not the only one who has


measured the gap

measured the shim,

compared the gap to the desired gap 

measured the new shim

installed the new shim


and then found that the resulting new gap isn't what is should be.   Good to not feel alone in this, but if we can't do this procedure logically, it gets sort of ridiculous.   


What I haven't done is measure my feeler gages with a micrometer.  That's next.  I have to use a couple combinations of feeler blades to get the clearance measurements...if one or more of them are not as marked...which I've read in comments from some of the feeler gage vendor listings...then I'll have the source of the problem.   Who knows where these feelers come from or how they're made or marked.  


I've worked in factories.   Things happen.  Places with really good procedures catch these things, but China's standards are sometimes not so fail-safe. I've been in factories there too! 


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Metric feeler gauges are critical as well as a reliable metric micrometer...I can't imagine trying to use Imperial feeler gauges and a micrometer graduated in inches and converting the figures!

I buy 2 sets of metric feelers gauges and take the blades I need from each one of these sets to make a dedicated set that cover just the range of sizes for the Intake and Exhaust clearances.

These 2 sets are here:

Creative Cycle Concepts https://bmwmotorcycleaccessories.com/metric-feeler-gauge-set/   This is a Hornig set, which is a German supplier.

Amazon https://www.amazon.com/gp/product/B0B7DZFZXV/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

I'll bring some of these to START to sell there.


I've seen some YouTube videos where the clearances were checked with feeler gauges with the primary markings in Imperial and an "Oh, buy the way" metric equivalent marked on each blade...I don't recommend this method unless you have no other choice.


With the critical nature of this procedure, it is worth it to buy the best tools you can.

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  • 3 weeks later...

Good question,

A precision set of Micrometer Inspection Gauge Blocks is what a professional machinist might use, but they can be above $600 for a quality set!


For the digital mics I use this works…

It is not an exactly perfect method, but I typically use a new shim marked around 2.30 as my “gauge block” to allow me to eliminate erroneous readings. 

So, if the known marked shim of 2.30mm reads 2.297 on the micrometer, I run the plunger back down to the anvil…almost…but when it displays 0.003, l re-zero the display.  Now, when I measure the known, marked 2.30 shim that was my “gauge block”, it reads 2.30.  It is more difficult if the reading is above the known value, because you now need to get a negative value on the display to apply your offset correction.  An example of this would be if the 2.30 shim reads 2.304, now you would need to force the plunger into the anvil to see a -0.004 and then hit the zero button.  This can also be done in steps to add the -0.001 to another -0.001 and so on, so it is not so hard on the mic. 

This is not that critical as you can just as easily note the offset from the known shim “gauge block” and apply that to any other readings for other shims…the difficulty comes from the fact that you have to have at least one shim with the original markings visible, which is not the case with any shims removed from the engine with some miles on it. 


Since all the 8.90mm shims we work with that I’ve seen either from OEM installed shims to all the aftermarket ones come in 0.02mm increments, you can pretty easily do some rounding to the nearest even numbered size and identify what it is. 

Just another case of “tolerance stacking” when there is a plus/minus value for the feeler gauge, the micrometer and the markings on the shims themselves. 
I try not to make it “Rocket Surgery”, or Brain Science”….whatever….

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Thanks Boxflyer

Appreciate your response


I should have been more explicit 

I meant in terms of purchasing a new micrometer

What parameters to look for in terms of quality?

This would be in relation to valve shim measurement for service on a R1200RT (2015)

Is a digital one a better option?  



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Oh...I misunderstood the question.

Sorry about the wordy response...


I use a digital one from Amazon. https://www.amazon.com/gp/product/B07DNNX9Y3/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

These are easy to read, allow for multiple functions, like display in inches or mm, and have a reset/zero button for quick adjustment.  (that button can also be a PITA if you accidentally press it).

I'm in the camp that inexpensive, does not always mean cheap, and products made offshore don't automatically get marked off my list of things to consider...lots of tools in my collection are made offshore and work very well. 


There are also mechanical micrometers available, but the increments on the barrel usually only allow for reading down to the 0.01mm graduations...somewhat hard to read in my digital world. 

Kinda like using an old style bar and beam type torque wrench.  These mics are also subject to the reading errors as described above, but much, much harder to adjust with a gauge block. 

MITUTOYO  0 to 25mm Range, 0.01mm Graduation, Mechanical Outside Micrometer


You didn't ask, but getting a torque wrench with a low range of accurate readings is also important for doing work on the Boxer engine.

Keeping an old rule of thumb in mind, that using a torque wrench in the lower 20% of the advertised range is inaccurate drives me to another inexpensive digital tool from Amazon.

Mini Digital Torque Wrench,1/4-inch Drive with Buzzer & LED, 0.66-22.12 ft-lbs(0.9-30 Nm)(8-265 inch pound)

Torque values for spark plugs are 12Nm, and for all the cam bearing bolts, 10Nm, and for the small pinch bolt on the LH Exh cam timing reluctor is 5Nm.

Appling the rule of thumb for the above torque wrench...the lower 20% of 30Nm starts at 6Nm, and is close enough for me for that smallest value, and easily covers any value below 15Nm where I always us these low range torque wrenches.

As an example, I broke this rule of thumb in my video series on YouTube I made back in the fall of 2018 where I used my Snap-On digital torque wrench with a range of 6.7-135Nm (5-100Ft/Lbs) where the lower 20% starts at 27Nm for accurate readings.

3/8" Drive Techwrench® Flex-Head Torque Wrench (5-100 ft-lb)


Again, you didn't ask...

I use 2 sets of feeler gauges I combined to end up with most of the blades needed to measure the range of clearances we need just for the 1200 WetHead and 1250 ShiftHead.

Jfbrix 32 Blades Stainless Steel Feeler Gauge with Metric  and this one also, Metric Feeler Gauge Set Hornig


The next thing that would be needed to do the valve clearance check is a selection of 8.90mm shims.  The most commonly used sizes are from 2.00mm thru 2.40mm.


Rental Shims.jpg

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Hi all 


Thanks for that info

Much appreciated

It appears Amazon doesn't ship that item (micrometer) to Oz so need to track down something similar locally



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