Does anyone have recommendations for washable air filters for a 1972 CB350?

[k2-350]

I'm not interested in spending big bucks on replacing uniquely-shaped paper air filters molded with sheet metal, mesh, and rubber hoses as one unmaintenanceable part on my bike. I like keeping things as simple to operate and maintain; paper filters cannot be cleaned and throwing them away is useless waste that cannot be recycled environmentally.

So in the order of long-term benefit to me- and the Earth happens to be a side plus- has anyone had good experience with oiled/washable air filters on bikes with the same style of air filter system as my CB350? Am I correct that the side covers can just mount on without the air filter underneath to support?

 

[EzPete]

How good are you at tuning carbs? It’s doable, but it’ll take some work to get it dialed in properly.

Or you just remove the paper from the filter element and replace it with foam.

 

[ancientdad]

This is the foam many have either glued or otherwise fastened to their old air filter frames after stripping the old paper element away.

Second entry on this page - https://unifilter.com/online-catalog/accessories/

other sellers, in case you're putting together a larger order of other stuff elsewhere

https://www.amazon.com/uni-filter-65-ppi-green-fine/dp/b000onzt5e

UNI Universal Filter Foam - 12" x 16" x 5/8" - Green

UNI bulk foam filter, this material is perfect for cutting and fitting to your stock air filter housing, replace old paper filter elements with new serviceable foam!

4into1.com

 

[stl360+450]

The original air filter elements were intended to be cleaned periodically, although 50-year-old project bikes often come with filters whose paper is beyond cleaning. The screenshot below comes from a CB360G Owner's Manual.



It is possible to replace the paper with new paper or with foam as Pete suggests, you can see examples of both in this thread. In my case the paper was taken from an automotive filter which produces additional waste. The foam option uses less new material and would be comparable to pod filters in that area.

The CB350 covers have tabs at the top, but not the bottom. They are also supported by a rod that inserts into the rubber grommets within the covers. Probably still usable without the air boxes, but perhaps not as robust.



I won't claim to be able to assess the relative environmental merits of the different filtration options, but I expect that new OEM style air boxes or new paper/foam in OEM air boxes will last a good long while.

 

[k2-350]

The original air filter elements were intended to be cleaned periodically, although 50-year-old project bikes often come with filters whose paper is beyond cleaning. The screenshot below comes from a CB360G Owner's Manual.

View attachment 57654

It is possible to replace the paper with new paper or with foam as Pete suggests, you can see examples of both in this thread. In my case the paper was taken from an automotive filter which produces additional waste. The foam option uses less new material and would be comparable to pod filters in that area.

The CB350 covers have tabs at the top, but not the bottom. They are also supported by a rod that inserts into the rubber grommets within the covers. Probably still usable without the air boxes, but perhaps not as robust.

View attachment 57655

I won't claim to be able to assess the relative environmental merits of the different filtration options, but I expect that new OEM style air boxes or new paper/foam in OEM air boxes will last a good long while.

Thanks for pointing me to the thread! I think i will do this. Luckily i still have the old ones to refurbish which fit much better than replacement filters i ordered

 

[stl360+450]

Thanks for pointing me to the thread! I think i will do this. Luckily i still have the old ones to refurbish which fit much better than replacement filters i ordered

Make sure you scroll down to see the foam option that many have used. It's easier and less messy than working with paper and glue.

 

[guzziart]

On my 350's the oem filters lasted 40-50 years. I replaced them with oem knock offs, if they last a fifth as long I'll be happy because it will be the next caretakers problem.

On another related note, fwiw, I think I saw a video that those guys in Houston produced about aftermarket filters that have a large enough diameter to fit the carb but as the tube runs back towards the filter, the diameter decreases which could cause engine performance issues e.g. restricted airflow at WOT, etc.