Found Objects

Marcel Duchamp, Fountain, 1917
Not all found objects are art, unless you’re talking about the art of troubleshooting.
(image: Wikimedia Commons, license: Public domain)

Since I live in sunny California, I eagerly anticipate the character-building cold whenever I visit Wisconsin for the Holidays. If I don’t get the winter wonderland postcard views that would inspire Robert Frost, I feel cheated. Therefore, while I was home this past Thanksgiving, I was very pleased when it started to snow.

My Dad loves his snowblower and, even though it was just a light dusting, he never misses a chance to use one of his favorite tools. He headed outside, but it wasn’t long before he came back in and said “I’ve got a good troubleshooting problem for you.”

My Dad encountered the following glitch: the snowblower suddenly died after a few minutes of use. He looked to make sure there was gas in the gas tank. Check. Using the electric starter, he fired it up again, but it only ran for a short time before the engine died like before. He tried a third time, but got the same result.

We looked at the manual and found the manufacturer’s troubleshooting guide. While my Dad was pondering that, I searched online and found an article about a guy that had a similar problem. I read the advice aloud: “Have you tried to run the engine with the fuel cap removed or loose? Sometimes the aperture in the center of the inside of the cap that allows the fuel tank to vent falls out…”

As soon as I said these words, the lightbulb went on for my Dad. He had found a mysterious black part in the driveway, but was unsure if it was even related to the snowblower. That’s because when inspecting the exterior, nothing was obviously missing. He mused, “Come to think of it, that thing I found in the driveway is round and about the same diameter as the gas cap.”

Snowblower gas cap with insert
The black rubber thingy was found in the driveway.
(image: © Jason Maxham)

Just a few minutes later, my Dad had fitted the black insert back inside the gas cap. I watched as he fired up the engine and started to criss-cross the driveway, once more dispatching the snow like Alexander the Great driving his enemies from the field. After a few minutes of operation, the engine continued to hold steady. He gave me the thumbs up and I headed back inside. Later he remarked, “I’m glad I didn’t throw that thing away!”

Principles In Action

Let’s tie what happened back to the universal principles of troubleshooting:

  • Be present: my Dad was aware of his surroundings, and this external focus led him to notice that something was out of place in the driveway.
  • Someone has already solved this problem: we’re talking about a mass-produced snowblower here. What is the chance we’re dealing with some kind of exotic failure that no one else has ever seen? Not likely!
  • Talking it out: discussing the problem and asking each other questions triggered the breakthrough.
  • Leftover parts: a veritable fix-it cliché. A repair project ends by triumphantly turning that last screw. But, just as you put your tools away, you look around the workshop and see something glimmering on the floor. What does this piece do? You probably want to find out.
  • Duplicating the problem: the failure condition was easily repeatable, which allowed testing of various hypotheses.
  • Verifying the fix: after replacing the black insert, my Dad gave the snowblower a good workout, rather than just putting it back in the garage.

But wait, what just happened?

The real mystery began after the fix was in place. I thought this would make a good case study for my blog, so I took a picture of the gas cap. Moving it around, trying to get the light right for a photo, I began to carefully examine this piece of red plastic. The manufacturer’s troubleshooting guide spoke of venting: one of the proposed remedies was to clear the venting hole in the cap of ice and debris. But, there were no apparent holes in the gas cap. Hmm…

That led us to wonder what the black insert actually did. Why did replacing it allow the snowblower to work again? Not knowing this, it was difficult to say for sure that the problem wouldn’t recur.

Untitled photo, possibly related to Shoveling snow off the sidewalk, Chillicothe, Ohio (Library of Congress, LC-USF33-003473-M2)
What is this mythical “snowblower” of which you so fondly speak?
(image: Library of Congress, license: Public domain)

For most people, the investigation would rationally end here. Normalcy had returned to the world of snow removal, and there’s an opportunity cost for learning more. While very useful and much beloved, my Dad’s snowblower isn’t a piece of equipment on which lives or livelihoods depend. If it failed again, there is a tried-and-true backup: that lonely and dented red shovel, which hangs in a forgotten corner of the garage, would simply be pressed into service once again.

Baffling Baffles

However, at this point, my curiosity was stoked and I wanted to know more. I began to read about the previously hidden (to me) world of gas caps. There are two primary types, vented and non-vented: the vented designs can be quite sophisticated, including one-way release valves that let air in but keep fumes from escaping. Just like everything else you take for granted, it’s much more complicated than what you’d think at first glance. Solving the problem of air flow and preventing a vacuum from forming within the gas tank is a very old problem and there have been many ingenious solutions implemented over the years.

Even after reading all this background material, that black baffle’s critical role in the workings of this specific machine remained unclear to me. Given that there is a large slit in the center post over which the baffle sits, an opening that would seemingly allow air to easily flow to the interior of the baffle, its role is perplexing. I asked some questions online and have yet to receive a satisfactory response…

So, I thought I’d pose the mystery to the very smart fixers who read The Art Of Troubleshooting. Can anyone explain why the absence of the black gas cap insert prevented the snowblower from working? What exactly does that thingy do?

*** Do you know the answer? Have a similar troubleshooting story to tell? Leave a reply below! ***

One Comment

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  1. if the rubber insert is easily flexible then it my sever the second half of the vented cap theory. it seals the tank from the outside, then a vacuum forms in the tanks, the air pressure rushes in through the red vertical shaft and bends the rubber piece out of the way. when pressure equalizes the rubber pops back into place to prevent fumes from escaping. my best guess.

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