Japie in trouble

Tech CasebookTech Casebook: Japie in trouble

When I still worked on the bench I used to worry about making costly mistakes. It can happen to the best mechanics; I was lucky that when errors did crop up, they were never very serious.
Now that I sit in an office these days while my team does the manual work, I still worry (as a good manager should).

Recently, a disgruntled customer barged into my office to complain that the misfire on his CitiGolf, which we cured a couple of weeks ago, had returned, and was worse than ever.

I found the jobcard, and discovered Japie had performed a 90 000 km service that included changing the cambelt. He also cured a misfire by changing the HT leads.

I asked Japie to investigate but as soon as he started the engine August strolled up and listened to the erratic idle. It sounded different than the usual misfire, so August gave his opinion that it was most likely due to incorrect valve timing.

I gave August the jobcard and asked Japie to observe. August removed the cover, found that the belt tension was too low, the timing was one tooth out and the belt had already begun to self-destruct. The low tension would have allowed the belt to jump a tooth.

He then fitted a new belt and showed Japie that the tension on the CitiGolf should be adjusted so that you’re just able to twist the belt through 90 degrees with your thumb and forefinger on the longest run between pulleys. Japie protested that he adjusted the previous belt the same way, but August laughed: “I suppose your 90 degrees is bigger than mine.”

I’ve never liked those belts. They were first introduced in the late ‘60s, but they seldom last as long as a well-designed chain or gear drive. The short life – in some designs less than 70 000 km – meant that automotive workshops were able to make money replacing, and sometimes mal-adjusting, engine parts that previously needed very little attention.

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