Pleated paper air filters can't get wet?

grhanka · 10-19-2021, 10:55 AM

Mud on the air filter made my son's 125cc pit bike sputter at high power. Removing the air filter fixed it, but washing the air filter did not. The wet filter restricted the air flow so much it was over-richening the mixture. It ran better the next day, after the filter dried out. Some guy online said paper filters expand and choke off airflow when wet, which is ridiculous, but I think I believe him. We are switching to foam. I just can't believe pleated paper filters can be so popular with such a massive defect. Did I miss something?

**JerryHawk250** · 10-19-2021, 11:01 AM

Best thing to get is a washable foam pod filter. Wash it out, let it dry out, then oil the filter.

franque · 10-19-2021, 01:45 PM

No, not a defect, just basic physics. Almost everything that is intended for off-road use gets a foam filter, and pleated paper for on-road designs. The exceptions arise with stuff like a Chinese pitbike, where they're built to be as cheap as possible, sometimes using whatever's on the shelf, or sometimes being built to a price point that is as cheap as possible, with a paper filter on the shelf is cheaper than a foam filter they have to order.

10-19-2021, 10:55 AM	#1
grhanka Join Date: Aug 2021 Posts: 58	Pleated paper air filters can't get wet? Mud on the air filter made my son's 125cc pit bike sputter at high power. Removing the air filter fixed it, but washing the air filter did not. The wet filter restricted the air flow so much it was over-richening the mixture. It ran better the next day, after the filter dried out. Some guy online said paper filters expand and choke off airflow when wet, which is ridiculous, but I think I believe him. We are switching to foam. I just can't believe pleated paper filters can be so popular with such a massive defect. Did I miss something?
	0

10-19-2021, 11:01 AM	#2
JerryHawk250 Moderator Join Date: Oct 2016 Location: Houma, La. Posts: 11,533	Best thing to get is a washable foam pod filter. Wash it out, let it dry out, then oil the filter. __________________ 2023 Lifan Lycan 250 Chopper 2023 Venom Evader 2022 Lifan KPX250 2020 Kawasaki Vulcan S 2004 Honda ST 1300 2016 Black Hawk 250 (sold) Keihin PE30 carb,125 main,38 slow.Pod filter,ported & decked head 10:1 CR,Direct Ignition Coil,15/40Sprockets,NGK DPR8EIX-9,De-Cat,Dual Oil Cooler,Digital Cluster 2016 Cazador180 XL 2014 Coolster150 JerryHawk250.com My YouTube Channel
	2

10-19-2021, 01:45 PM	#3
franque Join Date: Nov 2017 Location: Marseille, France -> Conakry, Guinea Posts: 1,481	No, not a defect, just basic physics. Almost everything that is intended for off-road use gets a foam filter, and pleated paper for on-road designs. The exceptions arise with stuff like a Chinese pitbike, where they're built to be as cheap as possible, sometimes using whatever's on the shelf, or sometimes being built to a price point that is as cheap as possible, with a paper filter on the shelf is cheaper than a foam filter they have to order.
	1