Yeh, I know it goes at the front, but instructions say 5mm righthand offset of centre, when looking at the front of the plane. However, that seems to be with the engine mounted horizontally with the exhaust port facing up, cylinder head to the right.

I'm fitting an OS52fs and have it mounted horizontally but with the exhaust port facing down and cylinder head to the left.i.e the other way around.

So, my question is, does the 5mm offset have to be to the left of centre?