Hi Jack, and Hi to all reading in, this is also my first post here, i have just picked up a what seems to be a mid 70's SB 45 17inch, wasnt running, but i pulled the engine right down, degreased it and cleaned all the carbon out of it, the fuel tank had water in it, and used a full can of carby cleaner on the carby, then put the engine back together with new plug and oil, gave it a full tank of juice,a squirt of aero start, 3 pulls on the crank and she fired up, now the only way to stop the motor is to earth the plug on top of the engine.
Your mower looks younger than mine do you know how old it is??