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We mill 2 planes on the threaded bushing so that it is possible to use a 22 mm wrench on the threaded bushing. This is necessary in cases where (for instance) the crankshaft bearing is glued to the bearing journal, to prevent the threaded bushing from rotating while tightening the central bolt

Very informatieve article by Duane Ausherman on “butterheads” and LK heads: http://www.w6rec.com/duane/bmw/head/

3 different breather plates have been used on the boxer engines:

The brake levers with finger grooves (PN32722072252) currently available in the market, do not fit in the throttle housing of the R26, R27, R50 – R69S models. The hole for the lever screw is of few thenth of a millimeter off it’s original position: the lever gets blocked and cannot be “opened”. New brake levers that do not have this problem are only expected to become available by the end of 2017. Till then, the solution is to mill off +- 0.3 mm from the edges on both sides. After polishing, no traces of milling are visible anymore. This is what
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Different exhaust pipes are available in the market, unfortunately not always an exact replica of the original pipes: the shape of the bends does not correspond with the original BMW exhaust pipes as can be seen on this picture. The 2 lower exhaust pipes are identical to the original pipes.   Next to that, these pipes follow a slightly different path than the original exhaust pipes. This causes a problem for the R67 – R67/3 models: in the horizontal section, they’re not running close enough to the frame, causing too little clearance between the brake pedal and the right-hand exhaust pipe,
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Table with part numbers Click here to view a larger table  

This modification and upgrade, using BMW components, results in a lower-ratio gearing for R26, R27, R50 and R60 gearboxes producing smoother, robust and responsive performance especially in 1st, 2nd and 3rd gear changes while 4th gear is unchanged. The “S” gear ratios allow the rider to accelerate smoothly through gear changes by letting the motor rev freely through an optimum power-torque range. Although the 3rd gear of both gearboxes have the same number of teeth, they are different: The standard gear has a diameter of 65.6 mm and the S-type gear has a diameter of 65.2 mm. They have a
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Different qualities emblems are found in the market. See this example of the R50S emblem. In our opinion, the upper one is the better quality, both in shape and in finishing.   The differences are easily recognized: for example the shape of the “5” and “S”   The upper emblem follows the contour of the rear fender, the lower one is too flat. The back side of the lower emblem doesn’t have the smooth finish of the upper one. Please note that these emblems are very fragile! During installation, make sure that the holes in the rear fender are exactly
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Overview of the different crankshaft shims used in the boxer engines

With hardly any new carburetors being produced by BING for the < 1969 BMW mono and twin motorcycles, it’s getting increasingly important to be able to repair and recondition the used original carburetors. Luckily, special parts and tools are available nowadays to restore the carburetors to a good working condition. A. Idle mix screw: very often, the M7 x 0.75 mm screw thread in the carburetor housing is worn out. There are 2 good solutions to this problem. 1. drill the threaded hole to 7.2 mm – cut M8 x 0.75 mm screw thread – install the idle mix screw with
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A printed copy can be ordered here: https://bmwclassicmotorcycles.com/index.php/catalogsearch/result/?q=RMR50R69S Free download here: Page 1-43          Technical data Page 44-59        Removal of power train Page 60-89        Engine  Page 90-101      Transmission Page 102-109     Final drive Page 110-123     Wheels, brakes and forks Page 124-149     Electrical equipment Page 150-157     Sidecar mounting Page 158-160    Wiring diagram    

The official pinstripe layout by BMW is as follows: Wide line: 5mm Narrow line: 1,5mm Distance between the two lines: 4mm   In the Barrington R26, R27 manual, following guidelines are given (measured on original fenders): – The setback of the wide stripe from the fender edge on many front and rear fenders is relatively constant at approx. 8.2 – 8.4 mm. – The wide stripes on 4 original fenders measured from 4.5 to 4.7 mm on one fender and 4.7 to 6 mm on another. – The gap between the 2 stripes on 2 rear fenders varied from 4.5 to
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