This bike, a 1975 R75/6, is the first BMW I bought and now has almost 106,000 miles on it. It is the first bike I rode more than 1,000 miles in one day back in 1976 and is the first build project I completed in 2010 and documented here:
Final Product of 2010 Restoration Project
I have several projects that I didn’t get to during the build. One of these is replacing the timing chain which I document here with a lot of pictures and detailed step-by-step procedure.
My bike has the duplex, dual row chain, while starting with the /7 series, the timing chain is a single row chain. This procedure should help you replace a /5, /6 or /7 series timing chain, but some of the parts will be different as I note later.
Since I stripped the bike I have the engine out of the frame, but most people will do this work with the engine in the frame. Although it is an option to remove the front wheel and forks to have clear access to the front of the engine, I think the work can be done without removing them.
Before starting this project, I reviewed material available on the Airheads Beemer Club site, www.airheads.org: I believe you can access the links below even if you are not a member, but consider joining this group if you want to contribute to the Airhead culture. I read material on Bob Fleischer’s blog site, and I posted a number of questions to the Micapeak Airheads forum whose members are legend for providing thoughtful advice and encouragement. You should add these resources to your toolkit as they are authoritative with valuable information.
In particular, I want to acknowledge Ron Cichowski, Tom Cutter, Bob Fleischer, Doran Shields, Marten Walkker and Eric Zwicky on the Micapeak Airheads forum for answering my questions. Also, a local Colorado Airhead, Don Wreyford, came by to kibitz and help with the disassembly process. Don has always been generous with his time and knowledge. And, my youngest son, Branden, shown in many of the photos with the electric yellow shirt, helped me on the entire project with wrenching, picture taking, and good ideas and advice when we needed to stop and reconsider what we should do next. He is turning into an accomplished Airhead wrench and lover of Bavarian iron.
Here are a couple pictures from the detailed writeup.
Ready To Start – Front and Top Covers Removed
Alternator Stator and Housing Removed as A Unit
Alternator Rotor Fits on Tapered Crankshaft Nose
Engine Electrics Harness with Labels
Cycle Works Inner Timing Cover Removal Tool
What’s Under the Inner Timing Cover
Crankshaft Nose Bearing and Sprocket in Cycle Works Removal Tool
Installing Bronze Color Back Plate With Screw Driver Blade
Verifying Crankshaft and Camshaft Sprocket Orientation (White Marks) After Installiing Timing Chain
Engine Electrics Installed Ready for Front Cover