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My brother, Gary, bought a new gas-powered weed trimmer a few years ago. Mine was an electric model, and Gary knew I had always wanted the greater power of a gas model, so he gave me his old one. Now, if you knew by brother, you’d know he wouldn’t go out and buy a new gas trimmer unless there was something wrong with his old one. But he assured me it worked fine; he just wanted a newer trimmer because it would have more features.

I’ve been using the trimmer, but not very often because it’s temperamental. I can always get it to start, but keeping it running is another matter. I tried to use it this past weekend, but, again, it seemed to run fine, then conk out. Then I remembered a series of articles we published several years ago, “Think first, then troubleshoot.” So I started to think.

I narrowed the problem down to a fuel or air problem and began an inspection. I saw two little tubes leading from the fuel tank, and one of the molded-in fittings for one of the tubes looked like it had been repaired. (Thanks for telling me, Gary.) Closer inspection revealed a crack, and fuel would seep out when I positioned the trimmer so that the fitting was submerged in fuel.

Bingo. If fuel came out, then air could get in. So I theorized that unless the trimmer was positioned to bathe the cracked fitting in fuel, air would get in to cause the engine to die. I fired up the trimmer and kept it oriented with the fitting facing the ground, and it ran like a charm. I got all the trimming done, then went online to order a replacement fuel tank.

As I mentioned in last month’s column, I don’t just edit material for Hydraulics & Pneumatics, I learn from it. You can, too. You’ll find the first of 12 chapters of “Think first, then troubleshoot” here. The series is geared toward finding the source of problems with hydraulic systems. No, it won’t solve every hydraulic troubleshooting problem you have. But as I discovered, troubleshooting is troubleshooting, no matter what the machine.

 

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This file type includes high resolution graphics and schematics when applicable.