The answer is : "until it squirts out of the top vent hole."
I honestly don't know the answer. I have a gallon container with a pump on it and fill it until it comes out the top hole. My manual doesn't list the capacity either...
I was pumping from a quart bottle of lube very slowly and it finally came out the vent hole. It doesn't seem like very much oil. But then again, the gearcase isn't very big either.
An 84 model 6hp takes 325 ml.
Its a different design of gearcase but the two cannot be vastly different in their capacities.
A genuine English quart is a bit more that 1100ml IIRC but I think an American one is a bit smaller so i'd expect it to take something in the region of 1/3 of a US quart.
Don't forget all the mechanical gubbins takes up a fair bit of space inside the box
An 84 model 6hp takes 325 ml.
Its a different design of gearcase but the two cannot be vastly different in their capacities.
A genuine English quart is a bit more that 1100ml IIRC but I think an American one is a bit smaller so i'd expect it to take something in the region of 1/3 of a US quart.
Don't forget all the mechanical gubbins takes up a fair bit of space inside the box
