Air filter positioning

[TONYT25T25]

Easy question for a Friday evening, my air filter box is of the square type so the filter can be placed incorrectly I think, does it matter if the flat/smooth surface part faces towards the air intake or the concertina bit.

[Mocki]

You mean upside down ? 
surely not .... 

you must mean the right way up but 90° 
I always put the filter in with the "fins" flat side to the air coming in from out side , rather than the gaps ? 

hard to explain isn’t it ! 

[TONYT25T25]

Thanks Steve, when I replaced mine I put it so that the fins/gaps were facing the air intake as I thought the flow of air would be easier, hard to work out which position is best, annoying that some of the simplest things can raise questions, I may change it round to your positioning. Engine runs ok but smells a bit rich especially on initial start up from cold, so trying to narrow down causes/rectifications.

[Mocki]

I’m not sure it’s going to make any difference to be honest, it still has to go through the same amount of filter to get up into the upper part.... that just how I do it 

[TONYT25T25]

Exactly, thanks again.