Restoring a 1973 BMW R75/5 Motorcycle

January 5, 2007

But wait, that’s not all

Filed under: 1973, airhead, BMW, motorcycle, R75/5, restore — Penforhire @ 8:43 pm

Okay, I told you we were entering the slow period. The time when I have to go earn a living. Wrenching in the garage sure is theraputic but it doesn’t pay any bills. In this case it seems to cost me more money, the more I wrench. You can really only hope for once-a-week updates with any juice to ’em.

I mean, here’s what I was planning to post as my entire mid-week update.


Oooh, a bunch of hose clamps! Believe me when I tell you these are much cleaner and shiny than they were. Alas, they are not done as there is still some scuzz that 600 grit and steel wool will not get off. Joe tried to convince me to use the really nice ready-for-bootcamp-inspection hose clamps in his parts box but I feel an obligation to at least try to recover as many parts as possible. Lots to show for the week, eh? But wait, that’s not all.

Joe got back to me on my question about disassembling the gas cap. His recollection is the job is a major PITA (pain in the). He ended up grinding off the head and still struggled with it. No wonder it wasn’t described in the Haynes manual. That book assigns a number of “wrenches” to let me know how hard a job is. One wrench means I can dive in after reading about it once. Five wrenches means call 911 now. Apparently the gas cap disassembly earns at least four wrenches. Well, I ordered the sealing-disk part anyway. The worst that can happen is I’ll buy a whole new gas cap, right?

On the topic of buying parts, it still amazes me how fast my on-line shopping basket passes $50. Put in a couple of rubber coupler hoses, some washers, some springs, and assorted tiny parts and suddenly the basket costs $54.92. Geez, it doesn’t feel like fifty bucks worth of stuff. I’ll try to keep all the parts receipts and present some totals in a much later post. I’m as curious as you are about how much this whole project will cost. You might call me foolish for going into it without a budget but I’m not on a timeline and I’m not about to give up. I may end up handing a bike-in-basket to a professional but I can’t see myself abandoning this rebuild indefinitely.

I received the carb rebuild kit I ordered from Eurotech Motorsports. I’ll get around to posting links to all my suppliers over on the side panel. I have some of those assorted parts I mentioned on order from Hammersly Cycles. They have a most-awesome on-line fiche system, indexed for each particular BMW model. If I can find it in an exploded view I can order it without knowing its part number. How cool is that?


But wait, that’s not all. Check out this bad boy. Can you tell what it is?


It is a special tool that only does one thing. It loosens the nut holding the muffler on to the cylinder. Here is a picture of the nut.


When I asked Joe about this he said a lot of folks use a drift at the base of one fin but you could end up knocking off a fin or making a gouge in the nut. But that wrench engages multiple fins and is the “correct” tool. So after I ordered the tool I got to thinking, “hmm, this tool is around $25. If I had to replace each nut how much would that cost? Stop! You’re thinking too hard again.” This tool only does one thing in life and you don’t need it very often. That means it’ll be thoroughly lost the next time I need it.

But wait, there’s more! This last picture is proof that blogs work. My General Manager at work, Brad, read my blog and noticed my complaint about how crappy currently legal-to-sell carb cleaner is (I think California has it especially bad). He recalled that he had an old can of real honest-to-goodness cleaning solution and he donated it to the cause! He even beat me to the blog-punch with a comment on the Origin page. Check out this can-o-toxic waste. I keep expecting the Toxic Avenger to crawl out of it.


The can on the right is what I found in stores. I think if you drink this all you need is a bottle of Pepto-Bismol. Now that serious can on the left is what Brad reverently handed me today. Even though it was packed nicely in a box I was sure it was going to open up in my car on my drive home and melt it. If you are tree-hugger you should probably skip the next sentence. The ingredients include methylene chloride, dichlorobenzene, and cresylic acid. I’m pretty sure if I swallow this stuff I’m a goner but there is no grease this will not cut.

I should come clean here and be serious for a moment. My education and my profession, to some extent, revolve around chemistry. In American business we were sworn off using methylene chloride as a degreasing agent years ago. It used to be premixed with freon in vapor degreasers as “freon TMC.” It is a chlorinated solvent and a known carcinogen (causes cancer). If you handle this mixture, Chemtool B12, or any similar chemical cocktail you should exercise extreme caution. Wear personal protective gear (gloves & goggles or face shield) and work only in well-ventilated areas. Wash off any contaminated skin immediately with soap and water. As Sean Connery said in The Untouchables, “here endeth the lesson.”


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