Back Back

2012 Kawasaki Teryx

Mod: Uni Air Filter and Prefilter Mod



While the first model year 2008 of the Kawasaki Teryx had a problem with the (black plastic) air plenum not sealing well onto the carb intake and allowing debris to get in, this is not a problem on later years like I have.
So my objective is not the plenum problem per se, but the way the stock Kawasaki filter seals to the airbox and plenum with some flimsy plastic clamp is very prone to not sealing well so I decided to address it.
I am not looking for a performance boost, I want engine reliability. Personally I do not believe that paper filters like K&N can capture fine dust effectively and am a firm believer in using a name brand oiled foam filter.


The Uni UK-1901ST air filter kit for a Teryx. I got mine at (actually Powersport Superstore) for about $75.
It is not just the filter but the entire kit which includes the billet adapter ring and hose clamp for the filter side. Uni makes great stuff as usual. I use their foam filter on my dual sport motorcycle also.

Here is a picture of it comparing it to the OEM stock filter.

The Uni filter itself is a one piece design but has an inner metal mesh cylinder that is very stiff to support the foam filter.
This mesh cylinder is a separate piece on the inside, which actually is removable if you gently work at it a bit.
The filter consists of red foam with a black rubbery molded end cap on the rear end with tabs to fit into the 2 air box slots on the rear, and the front of the filter is also black rubbery molded with a big round opening into which you can see the inner metal cylinder.

Oil the filter:

The filter has NO oil on it out of the box so you must oil it first.

Ok a sidebar here... after 40 years of using regular dino based foam filter oil and washing filters in gasoline or kerosene (both are obscene :), I am so glad there is a better way nowadays and I have accepted it gladly.
I use NoToil biodegradable oil but there are other brands like Uni, TwinOil or all the factory brands have their own bio oil. The beauty is that it cleans up in a sink with their biodegradable cleaners and is so awesome, convenient, safe AND green! The NoToil oil uses alcohol as a carrier to distribute the tacky oil then the alcohol dries up and leaves the oil intact.
By the way I also don't buy their cleaner but use a little Oxyclean powder in hot water to clean it with (can add a little Dawn detergent if needed also). You can literally clean an air filter on a trip by packing along a little bit of Oxyclean and using a motel bathroom sink!
Some say the special cleaners work better than Oxyclean and some don't think the bio oils are as effective. I'm happy. But I digress...

Ok to oil the filter I sprayed it liberally with NoToil spray filter oil and worked the oil in well with disposable nitrile gloves. I think it is best to pull the inner metal cylinder out the open front end in order to help work the oil into the foam better.
One thing I don't like about this filter is that the big molded end cap on the end is a little stiff compared to the foam and it makes it difficult to work the oil into the foam near the end cap while oiling or cleaning it.
In any event you must be gentle on the seams between the red foam and the black end caps as you massage the oil into the foam.

Just a warning, if you use NoToil you must use liberally and work it into the filter, it says right on the can that it is not a "spray and go" type but rather use liberally and remove excess oil.
Now that your filter is oiled you can reinsert the metal mesh cylinder inside of it again so it is ready to be installed.
Here is a picture of my cleaning setup. A 5 quart paint bucket from Ace hardware fits perfectly.


The kit comes with the filter, an aluminum adapter and a hose clamp.
To install, remove the plastic engine cover completely. This is so you can get at the hose clamp between the airbox and the engine intake plenum.
Remove the airbox lid. Now remove the OEM filter, you won't re-use any of it.

Now loosen the hose clamp on the outside of the airbox. Put the foam ring onto the Uni aluminum adapter. Put a little oil/grease on the embedded o-rings on the adapter (or not) and insert it from the inside of the airbox, through the airbox and into the engine intake boot. Tighten the existing hose clamp on the outside of the airbox onto the plenum.

Now you are ready to install the air filter. Note the 2 tabs on the rear molded end that have to go down into slots in the airbox. The filter fits very tightly and the whole filter has to be pushed forward firmly in order to get the 2 tabs to go forward and pop down into their slots in the airbox frame.
After inserting the filter, tighten the provided hose clamp to secure the filter onto the adapter.

Finally the airbox cover is installed and held on with the 4 clamps. This was the only part that seems a little difficult. The cover has a molding that pushes down on the back of the rear molded end of the filter to hold it in. And at first it seemed to not align properly but finally I was able to seat the cover and get the 4 clamps on. The rear seems very tight but yeah it fits.

Prefilter Mod:

After having oiled the filter once, I know it is a little difficult to clean and oil due to the molded ends on it. Here's a typical dirty filter, after 2 days in Moab.

I figured it would just be easier to clean a simple prefilter sheet of foam so I decided to make a simple prefilter myself. I purchased a sheet of Uni BF-1 Universal Foam Filter foam 12" x 16" x 5/8" green for $13 from

First I cut a template out of paper that fit into the airbox the shape that I wanted, then I cut the foam to the match the template. Note I cut a slit where it will fit over the rear black molded tab of the air filter itself, only a slit not a wide cut so that it grabs the molded tab snugly. I made the sides long to wrap around the size of the filter.
It fits well and I think it will work fine and be an easy way to block the major dirt and then clean it easily. Of course I oiled it before installation too! I haven't had any time on it yet but I'll update this with results eventually...

Back Back