Saturday, May 24, 2008

Why a B string is needed to fix motorcycles

After many years of working on motorcycles and cars, I find that the B string from a guitar is a necessary tool. Luckily, they are available everywhere musical instruments are sold and they are cheap.

And you might ask "Why do you need a guitar string to fix a bike, dude?" Or maybe not, but I'll tell you anyway. So far, I have discovered two major and one minor use. First use is to clear the tiny port in brake master cylinders that allows brake fluid to return to the reservoir when the lever is released. If this tiny port is blocked the brake pads do not move away from the rotor when the lever is released and the resulting friction causes heat, which causes the fluid to expand, which results in more friction, causing more heat... Well, you get it, a feedback loop that ends in the brake in question locking up and smoking. A bike with a locked up front wheel is not ridable, just ask Ted Speed! It was fixing his bike that lead me to the B string. Thanks to the Ascot Yahoo group, I learned this trick. I can use it on other master cylinders as well.

Today, I solved a long time mysterious problem on my BMW R100. It left oil spots on the garage floor. BMWs are not supposed to do this. I tried everything, but always had oil in the air filter area, which eventually worked its way to the floor.
Thanks to the Airhead List gurus I learned that the string had another use.

It turns out that there is a tiny hole that allows the oil caught in the breather system to return to the crankcase. If this tiny hole is clogged, the oil is sucked into the air filter area which explains the source. One hour disassembling and looking and 5 seconds of poking that B string through the tiny hole solved the problem. At least I hope so. I took it for a ride and so far no spots on the floor.

Of course, as always happens, while I had it apart I painted the starter cover (now the rest of the engine looks even uglier) and changed the voltage regulator, cleaned connectors and checked a lot of wiring, cables, and the like. I didn't break anything, which is common on the BMWs. On the Honda's it seems that any time a wrench is needed, a broken bolt may result.

I mentioned a minor use in addition to these two major purposes. That other use is threading carb jets on the wire while soaking or spraying them with bad solvents to clean them without getting said bad stuff on my hands. Lots of people tell me that one should never run a wire through a carb jet, but I have never followed all the instructions!

I make the assumption that a motorcycle is not needed to fix a guitar even if a guitar part is needed to fix a bike. I love learning something every day.

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