Log In / Register
0 Checkout
K&N Air Filter BM-1204
  • K&N Air Filter BM-1204
Savings (10%):

Select qty:

Add to Wish List

Video Review

K&N Air Filter BM-1204 Videos

K&N Air Filter BM-1204

K&N Air Filters are designed to achieve a virtually unrestricted air flow while maintaining filtration levels critical to engine life. The secret to their success lies in the unique characteristics of the filter medium which was originally developed by K&N all those years ago in the dust, sweat and tears of desert motocross racing.

The high flow cotton gauze air filter is washable, reusable and built to last for the life of a motorcycle engine. K&N air filters consist of four to six sheets of cotton gauze layered between two sheets of aluminum wire mesh. This media is then pleated and oiled to enhance its filtering capabilities and overall performance. K&N Air Filters were created for an environment requiring maximum horsepower and enhanced acceleration in addition to protection from the dirt and dust. The result is an air filter that allows dramatically more air into an engine, is washable and reusable, and will protect your engine for the life of your ride.

This Product Fits:
HP2 Megamoto 2007, 2008, 2009, 2010, 2011
R1200GS 20042012
R1200GS Adventure 20062013
R1200GS HP2 2006, 2007
R1200R 20072015
R1200RT 20052013
R1200S 2006, 2007, 2008, 2009, 2010
R1200ST 2005, 2006, 2007
R900RT 2005
R nineT R9T 2014, 2015, 2016
Product Style RevZilla Item # Manufacturer Product # Availability
K&N Air Filter BM-1204 857841 BM-1204 In Stock: Ships within 24 hours


Orders $39.99 and over qualify for our fast free shipping offer. Click Here for FREE Shipping Terms and Conditions.

Please see our International Orders page for orders shipping outside the US.

We show real-time availability on this product page when you select the size/color item you want.  Most items will ship the same business day an order is placed,however if an item requires additional processing time a message will be shown indicating such.

See our full Shipping Policy for further details.


If your order arrives and it is not right, we will we'll fix it, NO NONSENSE, we promise.

Doesn't fit or just not happy with it? You can return any new, unused and unaltered item within 30 business days of delivery receipt of your item. We will issue a full refund to your original payment method.

See our full Return Policy for all of the pertinent details.

Write a Product Review for a chance to win our monthly $100 giveaways.
K&N Air Filter BM-1204 4.7 5 3 3
This product seems to help my bike breathe better I bought the k&n filter after buying the Remus exhaust at the suggestion of my bmw service tech. It does seem to make a difference but I've already installed a power commander v and Remus cat delete header . The weather here in southern Illinois is bad right now and I cannot ride. I'm having some 12.1 compression Pistons installed now and will be anxious to see just how much power I've gained through the upgrades. I use k&n filters on mt trucks and do notice better fuel mileage. My tech said that a vehicle that has O2 sensors would definately notice a change in performance due to the vehicles computer learning the new air influx. It works on my diesel trucks and my gas burners as well. And as always revzilla came through. Because of the other recent purchases I made I had a $25.00 credit which made my air filter cost only just over $30.00 for my BMW r1200gs. Thanks revzilla. Keep up the good work. And thanks k&n filters for making filters that do not have to be replaced . March 2, 2015
BMW GSA K&N filter - easy upgrade I've used K&N on so many different vehicles of the years and they continue to be super easy to install, clean and use. They provide a marginal performance improvement, but I mainly like them for their durability and re-usability. June 2, 2014
Good choice for OEM replacement I have over 1000k on the filter and so far all good. No engine light and no other issues. The filter fits perfectly and it's easy to install. As a previous K&N filter user I truly believe that this filter is a good bang for the buck. OEM filters are very expensive. May 12, 2014
1-3 of 3
Use our Product Q&A for a chance to win our monthly $100 giveaways.

Have a functionality, fit, or otherwise product-specific question about the K&N Air Filter BM-1204? Ask it here! If you have a customer service or shipping question, please direct it to our Customer Service department.