Regarding Patent Page, December 2005, which states that all Hvid-type engines were 4-stroke. This is not so. Ransomes, Sims and Jefferies of Ipswich, England, built their Wizard engine of 2-stroke configuration about 1921-1923. The Wizard engine used the Hvid system of fuel injection and Ransomes held Australian patent no. 4,948, which states, "A fuel injection system for 2-stroke engines." It would appear that the Hvid patent was for 4-stroke engines only.
It could be interesting to obtain a copy of the English patent no. 179,075.
I have a Wizard engine that was purchased new by my grandfather in 1923 and is one of about 10 survivors out of a production of just over 600 engines. All survivors known are in Australia and England.
P.O. Box 19, W.
Goomalling, 6460 West Australia