Kev, if that's the same engine in the picture from the link you provided then you should tip mower on to it's right hand side, towards oil filler. (just make sure it's cooled down a bit in case of fuel spillage from carb).
You would do the same when changing (draining the oil).
The crankcase breather is on the same (left) side as the carb hence why it dumped the oil into the air filter casing.
Their info is wrong if they say left.
Edit: Just to clear up that "Golden Rule" thing, you often see this mentioned but in reality it's just there for people who don't understand how how things work, sort of a generic instruction. You'll often see people telling others to only tip the machine backwards resting on the handles as well. Although this is probably the safest way to avoid these issues it's also the most awkward way because the machine is sitting at a angle meaning you virtually have to climb under it.
You would do the same when changing (draining the oil).
The crankcase breather is on the same (left) side as the carb hence why it dumped the oil into the air filter casing.
Their info is wrong if they say left.
Edit: Just to clear up that "Golden Rule" thing, you often see this mentioned but in reality it's just there for people who don't understand how how things work, sort of a generic instruction. You'll often see people telling others to only tip the machine backwards resting on the handles as well. Although this is probably the safest way to avoid these issues it's also the most awkward way because the machine is sitting at a angle meaning you virtually have to climb under it.