Factual error: The motorcycle is not right for the period. It looks like a 1970's Kawasaki stripped down. Look at the rear wheel (too big), motor is 2 stroke (not one), and the exhaust has a muffler.
Suggested correction: There is no such thing as a one stroke engine.
I don't really follow the technology, but I happen to know there were at least one-stroke prototypes years ago. That aside, a "single-stroke" is possible, but may depend on how it is defined. That is, there will be an accompanying reverse "stroke" ["to" and "fro"], perhaps categorizing it as two-strokes? The "factual error" and your correction may both be correct, using different perspectives or definitions.