Ok, I have been reading the ST2 manual all week and have come upon the "ST2 Builds and Accessories" section. This explains the original option the engine came with from the factory. My build number (A28) says this:
Marine auxiliary triple survey, clockwise rotation, close coupled fan shroud for raised hand starting and with starter blanking plate. Long running/sump heater crankcase. Standard flywheel with starter ring. Fuel pumps set to no overload.
Governor set to 2600 rev/min
Governor range 1200-2100 (outside 8% governing limit)
2100-2600 (within 8% governing limit)
Can someone interpret that for me?
Here's a layman's thoughts
"marine auxiliary triple survey" probably just means it was intended to be used on a boat, but not necessarily as the engine that powered the boat but one that ran a generator or lighting, or other systems - and maybe that it was subject to "survey" in that there were rules governing its safe use in marine circumstances & maybe around it's maintenance schedules to keep it reliable so it didn't break down out in the middle of the bloody ocean
"clockwise rotation" is, well, clockwise rotation of the crankshaft when viewed from one particular end (and that doesn't matter to you, probably, cos it will only run in the way that makes the fan work properly to push air over the motor?)
"close coupled" usually just means something that is attached to the end of the crankshaft and driven (in this case the fan) as opposed to being driven by pulleys and a belt
"raised starting" maybe just means the design of the fan housing leaves room for a hand-crank handle as it doesn't have an electric starter motor
Which would be why it has the "blanking plate" over the hole where the starter motor would otherwise be?
"long running sump and sump heater crankcase" probably refer to the oil capacity of the sump (big sump = tolerance for a long run if no-one remembers to check the oil or if it isn't turned off for weeks at a time, maybe?) and maybe the oil system has a heater such as is common in cold climes so the whole goddamn motor doesn't freeze and seize? And so oil will flow on startup in cold temps, maybe?
"Standard flywheel with starter ring" (ring gear) suggests if you took the "blanking plate off you could probably fit a starter motor?
"fuel pumps set to no overload" might be something to do with the combination of the size of the element in the pump and the movement of the rack? Possibly set up so that the motor can't get enough fuel to hurt itself?
Other, better-informed folk will chime in here . . .