Had a new paper filter for my Polaris ATV get wet when it rained. It is dried out but a lot stiffer than it was before, and has some minor discoloration (brown) on it. Still any good?

Spray it down with WD40 and blow it out with compressed air and let it dry out.

if you drive your car in the rain does the air filter get wet??

Quoted: if you drive your car in the rain does the air filter get wet??

It can, but it doesn't matter as it's not enough water to cause a problem;  there's also massive amounts of air being pulled through it, so it dries quickly.

Now, driving through giant puddles w/out a snorkel can get you into trouble.  I hydro-locked a Jeep Wrangler 4.0 L engine by doing that.  The vehicle never got deep enough to have water pouring into the intake, it resulted just from the giant waves being thrown up - took a big gulp from one and sianara.  Snapped a rod, put a piston through the block.


AZ-K9, I concur with the above poster.  Blow excess water out with compressor, let it dry, and it will be fine.

Quoted: Spray it down with WD40 and blow it out with compressed air and let it dry out.

Spray a paper filter with WD40 and blow it out with compressed air?  
Only if you want to destroy it.

What kind of a paper filter is it?
Is it like a car air fliter, thin paper pleats?
Is it like a K&N filter, cotten fiber encased in a thin wire mesh?

If it's like a car filter and it was not dirty before and if the water that soaked it was clean water then you could "probably" let it air dry.

If it's a K&N type filter then get some degreaser soap, like Dawn dish soap or Forumla 409 and clean it out FROM THE INSIDE OUT, not from the outside in.

DO NOT USE COMPRESSED AIR TO CLEAN THESE TYPES OF FILTERS!!!!!!
DO NOT CLEAN FROM OUT OUTSIDE IN!!!!!!

If it is a car type paper pleat filter then now's the time to toss it and spend the money on a K&N filter.

Quoted: Quoted: Spray it down with WD40 and blow it out with compressed air and let it dry out. Spray a paper filter with WD40 and blow it out with compressed air?   Only if you want to destroy it. What kind of a paper filter is it? Is it like a car air fliter, thin paper pleats? Is it like a K&N filter, cotten fiber encased in a thin wire mesh? If it's like a car filter and it was not dirty before and if the water that soaked it was clean water then you could "probably" let it air dry. If it's a K&N type filter then get some degreaser soap, like Dawn dish soap or Forumla 409 and clean it out FROM THE INSIDE OUT, not from the outside in. DO NOT USE COMPRESSED AIR TO CLEAN THESE TYPES OF FILTERS!!!!!! DO NOT CLEAN FROM OUT OUTSIDE IN!!!!!! If it is a car type paper pleat filter then now's the time to toss it and spend the money on a K&N filter.

I have done this for years on paper pleat filters on 4-wheelers and other offroad vehicles. But I do agree that it should be blown out, from the inside out. YMMV

Quoted: Quoted: Quoted: Spray it down with WD40 and blow it out with compressed air and let it dry out. Spray a paper filter with WD40 and blow it out with compressed air?   Only if you want to destroy it. What kind of a paper filter is it? Is it like a car air fliter, thin paper pleats? Is it like a K&N filter, cotten fiber encased in a thin wire mesh? If it's like a car filter and it was not dirty before and if the water that soaked it was clean water then you could "probably" let it air dry. If it's a K&N type filter then get some degreaser soap, like Dawn dish soap or Forumla 409 and clean it out FROM THE INSIDE OUT, not from the outside in. DO NOT USE COMPRESSED AIR TO CLEAN THESE TYPES OF FILTERS!!!!!! DO NOT CLEAN FROM OUT OUTSIDE IN!!!!!! If it is a car type paper pleat filter then now's the time to toss it and spend the money on a K&N filter. I have done this for years on paper pleat filters on 4-wheelers and other offroad vehicles. But I do agree that it should be blown out, from the inside out. YMMV

Agreed.  Have done the same thing many times, and it has always worked fine.  Have never used wd-40 myself, won't comment on that.

I was making the assumption that this was a regular paper filter (as the OP asked about "new paper filter").  If it is K&N, I agree, it is a bad idea to use compressed air to blow it out (as the directions included with the cleaning/re-oil kit clearly state).

I use K&N air filters for my street bikes and for my cars.
For dirt bikes I use the "UNI" oil soak foam type filters, either OEM or aftermarket.

You NEVER use ANY type of solvent (which is what most of WD40 is) to clean a K&N air filter. Even the OEM K&N type filters state this.

You NEVER use compressed air to clean or dry a K&N type air filter.

From K&N:
www.knfilters.com/clningins.htm


1. APPLY CLEANER

Spray K&N Air Filter Cleaner onto both sides of the air filter until it completely saturates the pleated material.

A. Apply K&N Air Filter Cleaner to clean side of filter
B. Apply K&N Air Filter Cleaner to dirty side of filter

Allow cleaner to soak into both sides of air filter for 10 minutes to loosen the dirt. Do not let cleaner dry on air filter.

2. RINSE

Rinse off air filter with cool low-pressure water. Allow gravity to flush dirt out of air filter by applying water to the clean side of the filter; up and down the length of the pleats.

Continue to rinse the filter until all traces of cleaner are gone. If the filter is extremely dirty it may be necessary to repeat steps 1 and 2. If there are spots of dirt remaining on the filter, spray each spot directly with cleaner, allow a few minutes for it to soak and repeat rinsing step.

3. DRY

After rinsing, gently shake off excess water and allow filter to dry naturally.  Do not proceed to the oiling step until the filter is completely dry.  

CAUTION: THE USE OF ANY OTHER DRYING METHODS (I.E. COMPRESSED AIR, DRYER HEATERS, HEAT GUNS) COULD DAMAGE FILTER.

It's your filter, clean it how you want to.

I don't use the K&N filter cleaner.

I saw a K&N filter demo at the (old) Malcom Smith motorcycle shop back in the early 80's, they showed what happens when you use compressed air or solvents to clean a K&N filter. It fucks them up.

I should have stated this from the start.

What does the factory service manual (or the cheesey owners manual) say about the air filter?

If you don't have a factory service manual spend the money on one.

If it fits and still seals well its probly good. If it no longer has a tight fit, toss it...

Unless this thing costs a jillion dollars, why take a chance? Toss it and get a new one. It is filtering all kinds of microscopic dust from getting into your engine and causing premature wear. If most of the filter pores have sealed, then your engine is having to work harder at getting air, and may throw the mixture off. For fifteen-ish dollars, it ain't worth having to worry about.