To me the shaft end is the working end, and most motors pumps and engines are determined from the shaft end.
Most small engine turn clockwise on the rope or flywheel end.
Looking at the shaft end, shaft rotates counter clockwise.
So if you are direct coupling the transmission to the engine shaft, it should turn clockwise.
Using belts and pulleys, a pump could turn either direction.
Side be side, both turn the same direction.
Facing each other but off set, each will turn opposite.
Now if you know about single gear reduction and double gear reduction, you can change direction of rotation.
I am using the weed whacker as an example
Have you noticed the engine on a weed whacker on a curved shaft turns clockwise rope side, and looking down at the blade, it is turning clockwise.
Weed whacker engine on a straight shaft is also turning clockwise on rope end but looking down at a straight shaft weed whacker, the blade is turning counter clockwise.
How can that be you ask.
There is a gear box on the end of the shaft with a single gear reduction.
Some horizontal engines have shafts on both ends. One of my Kohlers has twin shafts. Some engines you can bolt on stub shafts, and they will turn clockwise.
Side story.
One of my friends installed an engine and transmission, and found out he had three reverse speeds and one fwd speed. As soon as he told me that, I knew he had used the stub shaft for the power to the transmission.