PC-85-928S

Does the arrow on the side of the air filter show the direction of the flow, or this side up?

rbrtmchl

You should ignore the arrows, as there have been reports of air filter elements with arrows in the up direction and in the down direction. The air filter mounts with the convex side up. Note that if you have already installed the air filter upside down with any running time, you should leave it as is, rather than correcting the orientation and then sucking the trapped dirt into the engine.

Alan

On flters arrow should indicate flow direction.

Alan

rbrtmchl

Here is a picture that I saved from another RL post (apologies, I don't know who to credit here). The picture shows two air filter elements oriented the same way, one with the arrows up, one with arrows down. As I said, I recommend that you ignore the arrows.

Bertrand Daoust

The convex side on top. Like the two here.

Ed Scherer

That would be either this one or this one. Or maybe even this one.

rbrtmchl

Credit to Ed Scherer!

Ed, thank you for posting the picture with the arrows up and down. This is one of those memorable pictures that is truly worth a thousand words.

Randy V

'Should' being the key word in this case.