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Tech Corner

Technical Q and A for classic motorcycle maintenance and repair.


Clean Aluminum Engine Block on BMW R75

Motorcycle Classics tech expert Keith Fellenstein

Editor’s note: If you’re having trouble with that old Suzuki, BSA or BMW, Keith Fellenstein is your guy. From motorcycle tuning tips to detailed motorcycle engine repair, he can draw from a wealth of experience to help guide you to success. Send questions to: Keith’s Garage, 1503 SW 42nd St., Topeka, KS 66609, or send an e-mail with “Keith’s Garage” as the subject.

Clean Aluminum Engine Block on BMW R75

Q: I have a 1977 BMW R75/7 and am trying to clean the aluminum engine block to bring it back to a newer looking condition. I thought you guys may know of a product to recommend to enable me to do this? I ask as I saw the BMW you restored. My R75/7 is in much better condition than the one you restored. The bike I have was inherited from my dad. He bought it new in 1977 and it has only 37,000km on it! — John/via email

A: Several readers emailed to ask about cleaning the aluminum engine casings on our project BMW. Editor-in-chief Richard Backus did that task himself. Richard says he used a variety of techniques, some more useful than others. He tried steam cleaning, which worked well enough a couple of projects back on the Honda 500 but did not work on the BMW. He also tried several solvent based products, but reported that the best results came from using Simple Green soap, a scrub brush and elbow grease. MC