At least the photo should give some amusement!
That’s why I’ve tacked a smaller pulley on the crank pulley,it then becomes too difficult to get the belt to grip and hold the motor.As above for speeds.
You’d be better of fitting a starter, or gearing up/down the lathe to get the right pulley speeds.
unless your running the lathe in reverse that engines going the wrong wayI assume its being rotated in the right direction.
Bob
Until I hand cranked a pump I didn't realise how hard it was to turn an oil pump; even though I replaced loads of worn ford1/4" hex drives.How is the oil pump driven? On the GMC the end of the dizzy turns the oil pump. So it was very easy to file a tang into the end of a bit of bar, and spin it up with a drill. I was surprised how much torque was required to get even 20psi
unless your running the lathe in reverse that engines going the wrong way