Review: DNA Stage 2 Air Filter Kit

A product the Transmoto team has tried, tested and would recommend to a mate.

WHAT IS IT?

Instead of foam, DNA filters use four layers of non-woven surgical cotton gauze, sandwiched between two pleated layers of epoxy-coated, marine-grade aluminium mesh, all wrapped in rigid polyurethane frame. They’re available for a wide range of brands and models, but our feedback here is specific to DNA’s Stage 2 Quick-Release kit (which comes complete with cage and filter) for Yamaha’s late-model four-strokes.

WHY WE RATE IT?

Of all the filters DNA produces, the Stage 2 Quick-Release unit made for the new-gen, four-valve YZ-F and WR-F models are perhaps the best because it offers instant, bolt-on power gains. Instead of the time-consuming process of cutting out the Yami’s spark arrestor mesh, you simply unbolt the standard filter base and replace it with the DNA’s metal frame, into which the DNA air filter element is fastened. The DNA is not the first filter on the market whose design increases surface area and airflow (though DNA claims to improve airflow on these Yamaha models by a whopping 55%), but by replacing the dome-shaped OEM filter with a flat element, the DNA also increases airbox volume, which, combined with the cotton gauze’s improved airflow, generates noticeable gains in power and throttle response. In doing so, though, it does not let more dust in. In fact, independent ISO 5011 filtration testing found that DNA filters block 98-99% of dust particles compared with a 92-97% filtration efficiency with foam filters tested.

We love the idea of an air filter that comes pre-oiled and ready to rock. And for subsequent oiling, it’s a simple matter of squirting the special DNA oil onto the cotton gauze from the inside and waiting. Because the oil automatically impregnates the cotton, there’s no need to massage it through with your hands. Once the purple colouration is evenly distributed, the filter is ready to install. Cleaning is a similarly easy process, though it is worth watching DNA’s online instructional video to understand the correct protocol. On the downside, removing the OEM filter base and spark arrestor mesh does make it easier for dirt to fall into the Yami’s vertical throttle body when replacing filters. Also, DNA filters are significantly more expensive than foam alternatives, and you will also need to purchase the $29 Service Kit. That said, DNA filters are designed to last much longer than foam, and they come with a lifetime warranty.

PRICE

You can get yourself the complete DNA stage 2 air filter kit for $169, or separately $99 for the filter element and $29 for the service kit from www.kenma.com.au

For more on the DNA stage 2 air filter kit watch our video on the product.