Adjust the Valves on BMW /5 Airhead Engines


| 4/10/2015 1:30:00 PM


Tags: September/October 2014, BMW, How-To,

If you own any one of BMW’s /5 twins from the Seventies you’re in good company, because when it comes to basic maintenance, few motorcycles are easier to work on. Simple and robust, they’ve become the poster child for sound German engineering.

Yet, like any machine, they require routine maintenance, and for this How-To we’ll take you through the process of adjusting the valves on a 1973 BMW R75/5. While BMW’s original maintenance schedule called for checking/adjusting the valves every 8,500 miles, we tend to operate on a 5,000-mile schedule if only because adjusting the valves on these bikes is so easy. The basic steps we follow here apply to just about every BMW airhead made from 1969 to the end of airhead production in 1996. While BMW constantly improved and changed the airhead engine over its long life, the basic architecture — and methods of maintenance — remained the same.

We should note that while the valve train on these BMWs is very reliable, one issue that plagued early engines was excessive noise from the rocker arms, caused by excessive end-float of the rocker arms on the rocker arm shaft and supports. If your valves are properly adjusted but you’re experiencing excessive noise from the rocker arms, there are several methods to alleviate the issue. We won’t cover those here, but there’s a good discussion of the issue at this BMW motorcycle repair information site. This problem was mostly limited to models built up to about 1974, when BMW changed the rocker arm support.

This is one job that won’t break the bank, with replacement parts limited to a set of valve cover gaskets: Factory gaskets list for $5.07 each.

john
9/22/2015 5:59:07 AM

Valve cover gasket leaks are common after 60,000 miles. Symptoms will include oil drips under the vehicle and burning oil smell from the engine compartment.Replacement of BMW valve cover gaskets can be relatively quick and easy on most models through the ‘80s and into the early ‘90s.Repair guide will be found from http://www.germanautowerks.com.


tonyc
4/16/2015 12:22:23 PM

While you're in there, it's a good time to check the lifter tube rubbers for cracks or leaks, and to break loose the exhaust nut, and regrease it so it doesn't seize.


keithf
4/14/2015 5:29:03 PM

If you have a BMW with a kickstart, you can always use that while watching the timing hole for the lettering to show up.


jhutbeer
4/10/2015 11:13:09 PM

About the line "Rotate the engine until the letters “OT” are centered in the access hole. " I rotated the engine by raising the rear wheel, putting the transmission in top gear and rotating the back wheel a bit at a time. Is there an easier/better way?





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