Francis learned his trade at Brooklands prior to the war and held the motorcycle record for the fastest ascent of the test hill using a JAP speedway engine. Post war, he became one of the best known Manx Norton engine tuners, much in demand by 500 folk. Clients included Ecurie Richmond and Stuart Lewis-Evans. Francis also branched out into modifying cars, most notably the Cooper Mk VIIa, a highly successful variation which prompted Cooper Cars to step up development for their Mk VIII.

Francis also played a key role in the mid engined revolution, pioneered by John Cooper. Cooper 500s were all mid engined, using a short chain to the gearbox and another short chain to the back axle but John, like all the other constructors, struggled to make a mid engine arrangement work for a shaft driven engine, Francis suggested using the Citroen Traction Avant Transaxle placed behind a Coventry Climax engine for the Cooper Bobtail and a racing revolution was born.