Out of 68 entries, comprising 52 four-stroke singles, 9 four-stroke twins, 6 two-stroke twins and 1 two-stroke single, sixty-four started the race and twenty-four finished.
The passage describes a race with 68 participants, where 52 ran four-stroke singles, 9 ran four-stroke twins, 6 ran two-stroke twins, and 1 ran a two-stroke single. Sixty-four vehicles started the race, and twenty-four finished.