Tom's BMW R850R Inside a Used Fuel Filter
Ever wonder what goes on inside your BMW motorcycle fuel filter? This is probably nearly identical to most automotive fuel filters as well.
I've split open my old filter, and have photos of the inlet and outlet. The short answer is: it works really well. My motorcycle had two cups (about 400 cc) of water in the fuel tank. This caused some rust in the bottom of the tank, but no other symptoms until recently. I tipped the bike over, and all the water ended up on the fuel inlet side of the tank. The engine developed an intermittent missfire. After checking a couple of things, and thinking about the evidence, I drained the fuel tank, opened it up, and checked the fuel filter. Of course, I discovered the water.
