Emergency Air Filter

Introduction: Emergency Air Filter

About: Woodsman and field tutor on a week day. Life long inventor, designer, engineer for the rest of the time. From items that make life easier to items with no reason to be....other than the idea popped into my hea…

MY poor old Marlin had been sat neglected under a cover for a couple of years as house remodelling got in the way. I gave myself a deadline to get her running again for an up and coming event.

A look under the bonnet (hood for you across the pond) revealed that the waterproof cover was not as advertised, water in the spark plug recesses and a very rusty top to the air filter... among other things.

I gradually worked my way through a list of items and had her up and running again.

It was when I decided to tart up the air filter that I discovered a problem just 2 days before the event.

Step 1: Disintegrated Filter

I lifted the filter off and found that the foam filter had turned to dust!

I got straight on the internet to find a replacement...that did not go well, this was a Saturday afternoon, I needed the car Monday, I could not find what I needed in the time frame I had.... time to think laterally.

Step 2: Alternative Filter Material.

I realised that I had some "scotch brite" scouring pads of various grades, the finest one (light grey) looked to be the one so I cut a few strips and ran them round the inside of the mesh surround.

Once the top rubber cover is pressed into place it seemed to retain the filter in place.

Step 3: Increase Its Filtering Capability

As it is the pollen season and the scotch brite is not as fine as the original foam I decided to give it a good spray of Silicon oil to try and catch any fine stuff.

Step 4: Finish It Off

I cleaned up the rusty chrome cover with a flap wheel and gave it a quick coat of black paint to make it look a bit better.

This has only got to last for one day of driving and I believe it will be better than running with no filter at all, I will let you know how it went :)


The Marlin and I had a lovely day out, she didn't miss a beat...... I still have not found the correct filter element so my fix may be in place for a bit longer.

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    2 years ago

    Hi, exactly the route I took yesterday afternoon :) I found the foam you mention on ebay and it will be with me before the weekend.

    My quick fix got me where I needed to go!


    Tip 2 years ago on Step 4

    You can buy'bulk' filter foam for motocross bikes, may be a better optionas foam filter never last more than a couple of years. Proper foam filter oil will trap more fine particles and also extends life of filter (to around 6 yrs in my experience if you don't have to wash it every weekend) K&N is a better option if you intend keeping Marlin for a while, I'm using some I acquired 'second hand' (used) in 1985. I'm guessing your in Britain? Try M&P or 'Busters' for 'Uni' or similar foam, they should be cheaper than local motorcycle shops