I've seen the issue come up many times where the fuel filter is black and is causing the engine to run poorly. There's a couple of things about this subject that have me completely baffled. What's in gas that makes this filter so filthy, and why is it necessary to filter this stuff out? The 109 has a fuel filter built into the fuel pump itself, so why the need for a 2nd filter? I've never changed the fuel filter in my car, it's got 232K miles on it, and it runs as good today as the day I purchased it. If my car's engine can deal with burning whatever this crap is in the gas that's turning this filter black, then why can't the 109? It almost seems to me that Suzuki decided to install this filter more as a business decision rather than from an engineering standpoint. They realized they could make money by selling replacement filters at ridiculously high prices. It couldn't possibly cost Suzuki more than a dollar or two to make this filter. There's nothing to it. It's pure profit. I'd be willing to bet if you removed this filter and replaced it with a straight piece of fuel line, you'd never know the difference.