Me Dad bought a Tigress twin, new, back when they first escaped. By L it was quick. Nearly had to fight the local filling station when he brought it home and filled the tank with "Straight" petrol.
"No mate, you need some two stroke oil mixing in there"
Often wondered why Triumph didn't throw the Cub engine away and use a modified Tigress engine in a motorbike frame, - - - - - Probably no market for a 250cc 4stroke twin?
No, we left that market to Mr Honda (P******s). Thus was the demise of the British motor cycle industry.
The BSA version of the Tigress was the BSA "Sunbeam" which also had a 175cc two stroke single option and was a pig for the Ladies to try to kickstart. BSA chairmans attitude to this was "If they can't start them, they shouldn't be riding them"
Battery box on Tigress/Sunbeam was on L/H legshield and the electric start variant had another fitted on R/H legshield.
Regards Ian