MSR FunnelWeb Air Filter

Company: MSR Hardparts

Price: $49.95

  • Unique design increases surface area while keeping the same size.
  • Stays cleaner for a longer period of time.
  • Durable, multi-use filter.
  • More expensive than most air filters.


  • Writer: Trevor Hunter
  • Photographer: Trevor Hunter

What it is

  • New foam air filter design.
  • Pyramid shaped foam for increased surface area and air flow.

The FunnelWeb Air Filter has a unique pyramid shaped foam design that is claimed to give it nearly twice as much surface area than a standard air filter. As a result, more dirt and dust is capable of residing on the filter before it loses airflow or needs to be cleaned. Utilizing a single layer of a single density foam, dust is said to be prevented from being trapped between multiple layers of foam which will help with cleaning and the performance of the filter. Also the company claims an injection molded urethane seal can provide a tighter and more precise fit rather than the traditional foam seal.

"The FunnelWeb Air Filter has a unique pyramid shaped foam design that is claimed to give it nearly twice as much surface area than a standard air filter. "

How it works

  • Stays much cleaner than the standard filter.
  • Different feeling when oiling it for the first time.
  • Provides a good seal against the air boot.
  • Durable and long lasting.

When first getting the FunnelWeb filter, you notice it is completely different from the traditional air filter design. Rather than increasing the size of the filter in overall size, they increased the surface area. The diamond shaped foam does a great job of accomplishing this. A smaller profile makes it much easier to install/remove the filter from the bike.

When applying filter oil, it feels quite a bit different due to the molded seal--it’s a little harder to squeeze the oil throughout the filter. The seal doesn’t bend as easy but after doing it once or twice it becomes second nature. Also, with the color of the foam being yellow, seeing where most types of oil has been applied and where more is needed remains very easy. With darker colored foam like red or black, being able to see the oil and knowing if a certain spot on the filter needs more proves quite difficult. In addition, cleaning the filter is pretty easy and it is no different from any other filter.

When MSR claims that it can go longer without needing to be cleaned, they weren’t kidding. Anyone in SoCal that’s familiar with Cahuilla Creek MX knows that the dirt there is extremely hard on air filters and can clog a filter in a very short amount of time. Same with some of our silty desert riding. After doing a thirty minute moto with the FunnelWeb filter and another slightly shorter moto with a different brand filter back to back, MSR’s had significantly less packed dirt on it than the others. An air filter exists as a vital component to the motor’s performance and longevity. With the filter staying significantly cleaner over time, you lose less power which keeps the bike running better. Additionally, you also decrease your risk of sucking dirt through the filter and ruining your motor. When a filter starts to plug it can suck dirt through more easily and we saw no signs of this.

The injection molded urethane seal is a nice feature as it provides a tight fit to prevent dirt from getting through. When removing the filter, less dirt was on the rim of the airboot when compared to the usual foam seal. Also, if you put grease on the rim of your filter, a small channel is grooved into the urethane seal to assist in preventing dirt from going into the motor.

After hours of use from the motocross track to the dry barren desert, the filter is holding up as good as any other. The foam hasn’t broken down at all nor does it have any tears in it. The seal looks like new despite having to be cleaned with gas once. Another interesting part of the filter is the plastic spider that is placed where the screw holding the filter in place sits. It keeps the foam separate from the screw providing a snug fit when tightened. Also, it has a groove on the bottom where the filter cage lines up, this aligns where the screw goes through the cage. With other designs, they can sometimes get misaligned and it gets difficult to get the screw directly through the cage. The pricing for this filter is more expensive than others at $49.95 but it also has performance gains with the unique design that the other filters do not have.  

Overall, the MSR FunnelWeb air filter is an innovative design and is almost revolutionary in the foam air filter world. Being able to drastically increase the surface area without increasing the overall size is a huge benefit of employing the pyramid shaped foam. Also, with the ability to stay clean and potentially go multiple rides without completing the pesky task that is cleaning and preparing air filters is another great benefit of utilizing this filter.

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"When MSR claims that it can go longer without needing to be cleaned, they weren’t kidding."