Cleaning Foam Air Filter with Gasoline

[seagull369]

Is it OK to use gasoline to clean a foam air filter (pre-filter or main oiled one)? I've used it in the past and it certainly does a good job in the cleaning dept., but I'm wondering if I'm damaging it/making it less effective as a filter.

I know these things have to deal with gas vapor and such all the time by nature of being on a carb, but when I dunk one in there to clean it, I've noticed the foam can expand (sometimes significantly) and doesn't always return to its original size. Also, after it's dried out, it sometimes feels less "spongy" or doesn't rebound from a squeeze as well as it did before.

Any thoughts?

 

[The Cobbler]

I wouldn't use gasoline. use mineral spirits instead

 

[PassnThru]

The prefilter is not exposed to gasoline so no reason why it should be immune to it. If your prefilter has gas on it you have a bigger problem.
You put oil on the prefilter to help with the filtering. You clean it with something that cuts the oil - something as simple as Simple Green or Dawn. You don't even have to get all the oil out - just clean it.

 

[littlefan]

small engines have used these filters for years and most makers recommend that dish soap be used to clean them. in the shops I worked in we kept a 5gal bucket with soapy water dunk and ring out blow dry reoil and your good to go

 

[JRC3]

small engines have used these filters for years and most makers recommend that dish soap be used to clean them. in the shops I worked in we kept a 5gal bucket with soapy water dunk and ring out blow dry reoil and your good to go

Yep Dawn. I use Dawn for so many things. KISS - Keep It Simple, Stupid.

 

[seagull369]

Thanks for the quick replies. I've used Dawn-type dish soap, and although I guess it gets most the dirt out, the filter always still looks stained. Guess I can't convince myself it's clean enough. I tend to put a real light oil coat on foam pre-filters (even when they're over paper elements), so you can imagine how even more discolored they get, esp. on something like a lawn mower.

Anyway, I'll get over it and stick with just the soap. Thanks again.

 

[ericlar80]

Dish soap - pick your brand of choice. I had a lawnmower clogged so bad that it wouldn't even start. Costco house brand (Kirkland Signature) dish soap fixed it right up.

 

[James-W]

I usually just replace it, they don't cost very much.

 

[ericlar80]

I usually just replace it, they don't cost very much.

A lot more than soap... not sure why people insist on buying things that are easier to fix than buy.

 

[wayne55]

I like Dawn too.

 

[James-W]

A lot more than soap... not sure why people insist on buying things that are easier to fix than buy.

The last ones I got from a friend of mine ordered them. He got some for foam filters for himself and he got some for me. I got 6 of them for $7.50 so they cost me $1.25 each. I see no reason to screw around trying to clean bug guts, grass and dirt out of a foam filter just to save $1.25. Call me a spendthrift if you want, but i will take a new foam filter every time over one that has been washed. Not saying you can't wash them and make them work OK, just saying for the small price it makes little sense to me to wash them. It would be like washing plastic knives, forks and spoons. Sure, you can do it, but what would be the point?

 

[jd_1138]

The last ones I got from a friend of mine ordered them. He got some for foam filters for himself and he got some for me. I got 6 of them for $7.50 so they cost me $1.25 each. I see no reason to screw around trying to clean bug guts, grass and dirt out of a foam filter just to save $1.25. Call me a spendthrift if you want, but i will take a new foam filter every time over one that has been washed. Not saying you can't wash them and make them work OK, just saying for the small price it makes little sense to me to wash them. It would be like washing plastic knives, forks and spoons. Sure, you can do it, but what would be the point?

Yeah I bought a 10 pack off ebay for like $8 or something. Free shipping. I gave the neighbor guy 3 of them.

 

[CJM8515]

I have had multiple bikes, atv's and other offroad type stuff over the years. Every single filter cleaned with gas. Dawn dishsoap does work but you will be there forever. Mineral spirits is less caustic but doesnt do that well of a job. For the cost of a new filter Ill just replace it every few years.

 

[seagull369]

Not saying you can't wash them and make them work OK, just saying for the small price it makes little sense to me to wash them.

Sometimes the filters are just not available, especially for vintage or unique equipment. They're also not always cheap either, esp when you get into the so-called commercial equipment, like Stihl, Husky, Exmark, etc. Not everyone runs a Briggs they made 5 million copies of. Sometimes you're forced to buy other parts along with the 2 cent filter that you need, which pads the bill.

Also. sometimes you just get stuck out there and need to get things moving again.

 

[James-W]

Sometimes the filters are just not available, especially for vintage or unique equipment. They're also not always cheap either, esp when you get into the so-called commercial equipment, like Stihl, Husky, Exmark, etc. Not everyone runs a Briggs they made 5 million copies of. Sometimes you're forced to buy other parts along with the 2 cent filter that you need, which pads the bill.

Also. sometimes you just get stuck out there and need to get things moving again.

If the foam filters are not available for your particular engine, or if they are quite expensive, then clean them if that is what it takes. I replace mine rather than clean them because they are readily available, they are inexpensive, and besides that, I don't need to change them very often anyway.

 

[Monza Harry]

I use dollar store shampoo (for oily hair) for my filters frequently, good for your hands too. I also make my own pre-filters with A/C filter material and a hot glue gun. When I played with go-carts the K&N filters [washable] were expensive and special order, the pre-filter extended filter life tremendously and the engine was always was clean inside. Harry

 

[Kevkx125]

Gas is a no it will eventually eat the treads holding the filter together, go to a motorcycle shop they sell cleaners just for foam filters.

 

[CarbonJoe]

Look into NoToil products for cleaning and oiling air filters. The stuff they make is bio-degradable and non-toxic, and you don't need to use gas to clean your filters. I've used it on my dirt bikes and r/c nitro vehicles. I like to have extra filters ready to go in zip loc bags, then just swap them out at the track. I see they now also sell motorcycle air filters, and have some that are available pre-oiled.

 

[xyster101]

I got 6 of them for $7.50 so they cost me $1.25 each. I see no reason to screw around trying to clean bug guts, grass and dirt out of a foam filter just to save $1.25. Not saying you can't wash them and make them work OK, just saying for the small price it makes little sense to me to wash them. It would be like washing plastic knives, forks and spoons. Sure, you can do it, but what would be the point?

The point is to keep **** out of the landfill. : I reuse plastic utensils as much as I can. We are such a throw away society, buy, buy, buy, use once, throw it out.

Take the filter, wash it, throw it back in, you are done. Takes less time then ordering new and throwing out the packaging. The new one will be ugly looking after 10 min anyway. I have a Ferris mower from '93 that starts every time.

 

[PNWguy]

Cleaning an air filter with gas is how my neighbor ended up in the burn ward. He had an open can of gas (a 3# coffee can), and something sparked. Big WHOOMP was heard 1/4 mile away, and then there was a large black cloud.

I know that many folks do it, and not everybody gets burned. Do what you like; I don't care.

 

[JRC3]

I usually just replace it, they don't cost very much.

Some might have very dusty conditions, or cutting tall weeds and such causing a need for frequent cleaning. That's a pre filter is for, to keep the air filter cleaner. That's also why they make main filters out of foam...For frequent cleaning.


Imagine under certain conditions having to change a simple $8 mower filter every month over a season. That's like 60-70 bucks.

 

[Slednut]

I know KTM states in their manuals that no petroleum product should be used to clean foam filters.

After cleaning a lot of guys use motor oil in their filters. Using a product for foam filters makes the filter perform much better.

Bel-Ray makes a good foam filter oil.

 

[James-W]

The point is to keep **** out of the landfill. : I reuse plastic utensils as much as I can. We are such a throw away society, buy, buy, buy, use once, throw it out.

Take the filter, wash it, throw it back in, you are done. Takes less time then ordering new and throwing out the packaging. The new one will be ugly looking after 10 min anyway. I have a Ferris mower from '93 that starts every time.

Well, I guess if you want to wash plastic eating utensils that is your right. But to my way of thinking, if you intend to wash them then you may as well use metal ones. The whole idea of plastic eating utensils is so that you can just throw them away rather than washing and reusing them.

But getting back to foam filters, if you want to wash them out and use them over again, by all means, do so, I certainly wouldn't want to discourage you from doing it. I don't wash them and reuse them because the ones I need are cheap and I don't need to replace all that often.

 

[R1Rider]

generally, yes. We used to clean our moto-x filters with gas, then simple green and dawn to get them super clean. Just dont get the gas on your hands, not good for you.

 

[ericlar80]

Well, I guess if you want to wash plastic eating utensils that is your right. But to my way of thinking, if you intend to wash them then you may as well use metal ones. The whole idea of plastic eating utensils is so that you can just throw them away rather than washing and reusing them.

But getting back to foam filters, if you want to wash them out and use them over again, by all means, do so, I certainly wouldn't want to discourage you from doing it. I don't wash them and reuse them because the ones I need are cheap and I don't need to replace all that often.

That is a false equivalency. Foam filters are intended to be washed but can be replaced when needed, whereas plastic utensils are intended to be thrown away (I.e. disposable). It’s not like they also make a filter made of metal and the foam one is meant to be tossed.

 

[James-W]

That is a false equivalency. Foam filters are intended to be washed but can be replaced when needed, whereas plastic utensils are intended to be thrown away (I.e. disposable). It’s not like they also make a filter made of metal and the foam one is meant to be tossed.

As far as I am concerned, a foam filter that costs $1.25 is disposable.

 

[JRC3]

As far as I am concerned, a foam filter that costs $1.25 is disposable.

What examples of $1.25 filters are we talking here? I'm just curious.

 

[James-W]

What examples of $1.25 filters are we talking here? I'm just curious.

Here is an example, this is the filter rather than the pre-filter, but you will get the idea. The pre-filters are even cheaper, they are just a little thin piece of foam that filters the air prior to going into the main air filter. Look down further on the page and there are examples of some other filters.

https://www.amazon.com/dp/B013SK4NEW/?tag=atomicindus08-20

The ones I use a buddy got for me, not sure where he got them, but they cost me $1.25 per filter. He got some for himself and perhaps for other people too, not sure about that but very possible. Many times if you order in bulk you get a better price.

 

[captmoto]

I have seen gas **** up plenty of shops and garages. Using gas is literally a ticking time bomb. You can buy Gunk engine degreaser at Vato Zone on twofer sales all the time. Cleaning small engine pre-filters, these two cans would probably last a lifetime. My air filters cost $35 each and this is what I use.

 

[yeldogt]

Years ago all the manufactures would recommend cleaning the foam pre-filter with gas ... typically they were all oiled after. I'm sure EPA regulations ended that.

every shop had a small container around to do this .... I'm sure a lot of people just tossed the excess (not good)

They have become more of a throw away item today .... Example -- the OE Honda filter is $25 .. and I can get 5 knockoff replacements for the same price. Not as nice as the OE

 

[JRC3]

Here is an example, this is the filter rather than the pre-filter, but you will get the idea. The pre-filters are even cheaper, they are just a little thin piece of foam that filters the air prior to going into the main air filter. Look down further on the page and there are examples of some other filters.

https://www.amazon.com/dp/B013SK4NEW/?tag=atomicindus08-20

Well that certainly is plenty cheap enough. If I had dusty conditions that's certainly the route I'd take.

 

[yeldogt]

Here is an example, this is the filter rather than the pre-filter, but you will get the idea. The pre-filters are even cheaper, they are just a little thin piece of foam that filters the air prior to going into the main air filter. Look down further on the page and there are examples of some other filters.

https://www.amazon.com/dp/B013SK4NEW/?tag=atomicindus08-20

The ones I use a buddy got for me, not sure where he got them, but they cost me $1.25 per filter. He got some for himself and perhaps for other people too, not sure about that but very possible. Many times if you order in bulk you get a better price.

Stuff is cheaper vs what it cost 40 years ago -- manufacturing/ supply chain. The gas to clean it costs 1/4 of the price to replace it.

 

[Bretny]

I tryed club soda and oxy clean powder on a K&N in my RZR side by side. This filter is down by the rear tire so is almost always dirty. It worked so well i cleaned the rest of the quad filter i owned. The rest are foam with rubber caps.

I would do this on a $2 or even $10 filter. The filters i cleaned totaled over $100 and have only been washed in dish soap.

 

[fsae0607]

They used gas as a parts cleaner back in the day. Dangerous, but it worked.

I'd use mineral spirits then a water-based degreaser.

 

[madison069]

Nobody else uses Dawn dish soap to wash those foam lawnmower filters?

 

[JRC3]

Nobody else uses Dawn dish soap to wash those foam lawnmower filters?

I think that was addressed around post #4-5.

 

[bdbecker]

Call me crazy, but I've always used a foam filter cleaner and oil kit.

https://unifilter.com/cleaning-oiling/

 

[Warrenator]

Remember Gasoline ain't what it used to be. There is alcohol in there now, so instead of one solvent there are two, one of which may attack the foam.

I'm sure it was not damaging to the foam filter 20 years ago to use gas, today I'm not so sure.

And last time I cleaned mine I just vacuumed it off from because I had a vacuum and I didn't want to go to the house and wash it, also didn't want to go to the shop and use stoddard solvent and then find some oil and then squeeze and wait etc..... Close enough. Lawnmover runs great.