TECH CASEBOOK: Two-stroke Morris


The previous story reminded me of my uncle Karel. In his youth he owned a two-stroke DKW, which was produced by the German Auto-Union company, which was formed in the 1930s by the combining the DKW, Audi, Wanderer and Horch brands. I think it is quite a pity that only one of those brands survived.

Oom Karel was very happy with his DKW, but it was too small for a growing family, so he replaced it with a Plymouth. Later, in his old age, he bought one of the first overhead valve Morris Minors, and this served him well – at least for the first few months of ownership.

I was an apprentice at the local Morris dealer at the time, and he came to see me one day. His engine had started to smoke and became very difficult to start. I found the spark plugs had carboned up, and the compression readings were low. By then I knew that the first series overhead valve engines were oil guzzlers so the smoking didn’t bother me. I cleaned the spark plugs and advised him to go away for a weekend to burn the carbon away.

Just before he left he casually remarked that he expected this car to last him for the rest of his life. He pampers it by adding oil to the petrol the way he had to do it with the DKW.

Well, it took a lot of explaining, but I eventually convinced him that four-stroke engines don’t need oil in the petrol.

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