Granddad Art and Dad were the only mechanics we could afford so anything that broke, they fixed. Our farm machinery was all second hand and mostly old so there was no lack of work. The Ford tractors were particularly troublesome.
One of the Ford’s had broken down and wouldn’t start. Granddad towed it down next the shop and began the “Fuel, Spark” ritual. Having cleaned filters and primed the gas pump to no avail he began to investigate spark. There is a method in which you take one of the spark plugs loose, then using a screwdriver or other tool as a shorting rod check to see if the spark is being generated. He took the plug out, propped it up with the screwdriver and pressed the starter button.
Suddenly he yanked his hand free, jumped back and danced a little jig around the yard! “Lots of Spark! Lots of Spark!” was all he said much to the credit of him and his Quaker upbringing.