Good day,

I was sent this earlier from another Airhead Ron Kitchen and thought after reading it, its worth having the rest of the BMW Airheads and for that matter anyone who runs carburetors on their motorcycles:

The Carburetors Basic Secrets!

The basic secret of carburetor function is that inside each carburetor are thousands of tiny gnomes, each with a small bucket. As you open the throttle more of these gnomes are allowed out of their house and into the float bowl, where they fill the buckets and climb up the carburetor’s passages to the intake, where they empty their buckets into the air stream. But, if you don’t ride the bike for a while, bad things can happen. Tiny bats take up residence in the chambers of the carburetor, and before long the passages are plugged up with guano.

This creates a gnome traffic jam, and so not enough bucketfuls of fuel can get to the engine. If it gets bad enough, the gnomes simply give up and go take a nap. The engine won’t run at all at this point. Sometimes you’ll have a single dedicated gnome on the job, which is why the bike will occasionally fire as the gnome tosses his lone bucketload down the intake. There has been some research into using tiny dwarfs in modern carburetors. The advantage is that unlike gnomes, dwarfs are miners and can often re-open a clogged passage.

Unfortunately, dwarfs have a natural fear of earthquakes as many a miner should. In recent tests, the engine vibrations caused the dwarfs to evacuate the Harley-Davidson test vehicle and made a beeline for the nearest BMW dealership. Sadly, BMWs are fuel injected and so the poor dwarfs met an unfortunate end in the rollers of a Bosch fuel pump.

Other carburetor problems can also occur. If the level of fuel in the float bowl rises too high, it will wipe out the Section 8 gnome housing in the lower parts of the carburetor. The more affluent gnomes build their homes in the diaphragm chamber, and so are unaffected. This is why the bike is said to be “running rich.” If the fuel level drops, then the gnomes have to walk farther to get a bucketful of fuel. This means less fuel gets to the engine. Because the gnomes get quite a workout from this additional distance, this condition is known as “running lean.” The use of the device known only as the “choke” has finally been banned by PETG (People for the Ethical Treatment of Gnomes) and replaced by a new carburetor circuit that simply allows more gnomes to carry fuel at once when the engine needs to start or warm up. In the interests of decorum, I prefer not to explain how the choke operated. You would rather not know anyway. So that is how a carburetor works. You may wish to join us here next time for Electricity 101, or how your bike creates cold fusion, inside the stator, and why the government doesn’t want you to know about it.

Shared by Gordon Cansdale/Round Corner, New South Wales, Australia ■