Okay probably a stupid question but idk answer so here it goes

[cbrjuly380]

I have a Husqvarna yth1842 with a B&S 18.5 intek engine. Question I have is do i use the yellow pre filter when replacing air filter or remove it first? TIA

 

[StarTech]

The pre-filter is there to keep the main filter cleaner longer. Without it the main filter get dirty a lot faster but you can use the mail filter without it.

 

[GearHead36]

A pre-filter should be oiled. A properly oiled pre-filter will catch most of the dust & dirt, and can be cleaned and re-oiled, which will prolong the life of the pleated paper main filter.

 

[ILENGINE]

A pre-filter should be oiled. A properly oiled pre-filter will catch most of the dust & dirt, and can be cleaned and re-oiled, which will prolong the life of the pleated paper main filter.

A properly oiled pre-filter is the key. Which everybody over oils the pre-filter so the current recommendation from the OEM's is to not oil the pre-filter on engines that use a paper main filter. An over oiled pre-filter will cause more harm than good

 

[cbrjuly380]

A pre-filter should be oiled. A properly oiled pre-filter will catch most of the dust & dirt, and can be cleaned and re-oiled, which will prolong the life of the pleated paper main filter.

an oiled air filter?

 

[ILENGINE]

an oiled air filter?

Foam only filters need to be oiled. It was common practice to oil the foam wrap pre-filter around the paper cartridge style filters, but if it was over oiled which most people did. The oil would soak into the paper filter clogging it. So common practice now is to not oil the foam filters in combination with the paper style filter.

 

[GearHead36]

an oiled air filter?

That thin foam thing that goes on the outside of the paper filter... that's the pre-filter, and is supposed to be oiled. At least, on Kohler engines they're supposed to be oiled. If oiled & maintained properly*, it will make the paper filter last a long time. If over-oiled to the point that the oil runs onto the paper filter, it will ruin the paper filter almost immediately. An oil-soaked paper filter is toast, and needs to be replaced. I've tried cleaning them, but they're never the same again.

* A properly oiled filter... pour oil over the filter, in a large ziplock bag is good, work the oil in, then squeeze out as much oil as you possibly can. Kohler says that it should be serviced (cleaned & re-oiled) every 25 hrs.