Directions for adjusting the gap on a spark plug using a spanner with a built-in feeler gauge.
| Identifier | ExFiles\Box 33\3\ Scan208 | |
| Date | 23th March 1922 guessed | |
| DIRECTIONS FOR ADJUSTING. To adjust the gap, use the small spanner and loosen the nut, only slightly. The feeler gauge end of the spanner has four graduations, the first being 10 thous. of an inch, the second 15, the third 20, and the fourth 25. Having loosened the nut slightly, insert the feeler gauge end of the spanner between the point and the side of the Plug until the desired mark is reached. Having forced the feeler gauge to the required distance remove the gauge and tighten the nut, care being taken to see that the nut is tightened without disturbing the setting. This can be effected very easily by holding the point finger of the Plug with the thumb nail of the left hand while tightening the nut. | ||
From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).