Air filter foam

[CornishPete]

Can't find a replacement for a honda crf70. It's just a piece of foam but I assume it's designed for the job. Does anyone have any recommendations for some foam that I can cut to size? Many thanks!

 

[pedrobedro]

Fish tank filter foam

 

[hotponyshoes]

Go onto ebay and search for pipercross or k&n etc air filters,
You will find one to fit something obscure like a Volvo for a couple of quid. Cut a few out of it then you can wash and reuse as required

 

[The_Yellow_Ardvark]

Fabic Land did some foam I have used as air filter material.

 

[stuvy]

https://www.motorcycleproducts.co.u...2ACUAVU1DhfMa_lD4ZBjOEzOtAaNUhShoC-yAQAvD_BwE

 

[hermetic]

any type of open cell foam that you can breathe through will do the job, I have used all sorts of different types of foam for air filters, and never had a problem. The assertion that it is in any way "special" is a myth!

 

[dobbslc]

Don't use anything that's not designed for use as engine air filter material though as it can dissolve in petrol and get sucked in!

 

[dobbslc]

any type of open cell foam that you can breathe through will do the job, I have used all sorts of different types of foam for air filters, and never had a problem. The assertion that it is in any way "special" is a myth!

Probably right but for £4 is it worth it?

 

[Memmeddu]

https://www.ebay.it/itm/182346014174


Athena air filter for Honda CRF-70

 

[bricol]

https://www.amazon.co.uk/Ramair-Fil...eywords=Ramair+Filters&qid=1609274376&sr=8-10

 

[hermetic]

Don't use anything that's not designed for use as engine air filter material though as it can dissolve in petrol and get sucked in!

If your air filter is full of petrol you have a far bigger problem than the wrong foam!! what you are saying is your assumption based on what you "think" might be the case, what I am telling you is based on much experience of filters on cars, motorcycles, and tractors. You must of course use wire mesh between the inlet port of the carb and the foam, or the whole lot will be sucked down the ole! I would have thought however that this was pretty obvious! When I clean foam air filters, I generally wash them in petrol, never had one dissolve yet!
Phil

 

[Gwil]

Go onto ebay and search for pipercross or k&n etc air filters,
You will find one to fit something obscure like a Volvo for a couple of quid. Cut a few out of it then you can wash and reuse as required

Beware Pipercross. Had one in my Harley. When I delved inside the fantastically hard to remove air box the thing was shredding and ungluing itself after 5000 kilometres. Discovered many people online have had the same problem. Binned the airbox and bought a Free Spirits intake and filter.

 

[dobbslc]

If your air filter is full of petrol you have a far bigger problem than the wrong foam!! what you are saying is your assumption based on what you "think" might be the case, what I am telling you is based on much experience of filters on cars, motorcycles, and tractors. You must of course use wire mesh between the inlet port of the carb and the foam, or the whole lot will be sucked down the ole! I would have thought however that this was pretty obvious! When I clean foam air filters, I generally wash them in petrol, never had one dissolve yet!
Phil

Mmm I've never had a foam filter element that didn't stink a bit of petrol / oil on a carb fueled bike and I'm not talking about some old ****ers. I've also seen half dissolved filter elements a few times. I don't think that, I've seen it. What I'm saying is don't use some unknown foam as a filter if you can buy the right stuff cheaply.
I've also had plenty of experience with cars, bike, small plant but definitely no tractors!

 

[CornishPete]

https://www.ebay.it/itm/182346014174


Athena air filter for Honda CRF-70

Thanks for the link but that's about £25! For a piece of foam!!

https://www.amazon.co.uk/Ramair-Fil...eywords=Ramair+Filters&qid=1609274376&sr=8-10

That's just like what I was thinking!

I have soaked the old one in petrol to clean it for now. There's a breather pipe that runs from the crank case into a little plastic box then into to the air filter so I guess it will inevitably foul with some sort of oily/petrolly gunk!

Thanks for your replies!

 

[Memmeddu]

A wrong air filter may cause much more problems than what somebody could think.
You can make one for a small engine.
But for a vehicle I wouldn't trust to make one.