
Finally, the completed bike! After completing the rebuild, I added a set of Chase Harper saddlebags and some other extra bits. This is a nice studio shot a friend of mine did of the completed project.
Restoring a 1973 BMW R75/5 Airhead Toaster Motorcycle.



There are many discussion online about how best to clean engine and other parts. Here's my condensed version. I used an engine degreaser sparingly, and only toward the bottom of the engine case where I saw grease or oil. I tried Simple Green Max a bit because some people highly recommend it. It's supposed to stain metal easily, so unless it's summer and you have a way to easily rinse the parts off (and your careful not to get water where it shouldn't go), I'd probably avoid it. To clean between the cylinder fins, I used Luster Lace. It's a great product that comes in long strips, useful for cleaning hard to reach areas and especially for twisting around spokes and such. For broader areas of the engine block and other metal parts, I tend to use Nevr-Dull, a wadding available at many auto parts stores. And for the final polish on most any metal, you can't do better than German Monidur metal polish (available from Hucky's and elsewhere).
Of course, you don't have to use all of these products together or in this order, or at all, just whatever works best for you.

As I was disassembling the bike, I also noticed another problem...the two leaking pushrod tube seals above. An inspection showed the same problem on the other side. That's what happens with seals that are almost 40 years old!