Hello.

I have a 2015 400cc Burgman and am considering fitting a K&N or similar type air filter. I see other people have done this and would appreciate some opinions on which one to go for and advice on fitting etc.
Thanks.

There are two approaches to this. You can retain the air-box and fit a filter which is a direct replacement for the stock item. This doesn't cause any problems and has marginal benefits such as needing no further replacements for a very big mileage. The only K&N alternative I have tried ( on Guzzi and KTM ) is the DNA make
https://www.dnafilters.com/en/product/M ... Air-Filter
They work well enough although claims are usually exaggerated.

The second method is complete removal of the standard air box and replacement with a cone filter. This gives more scope for experimentation but as a direct replacement will usually work very badly. This is because the air flow/camshaft timing is designed with a known amount of resistance and a known effective inlet tract length and most cone filters change this completely. It is possible to to introduce your own intake pipes and filter enclosures ( I used plastic waste pipe and suitable tin cans ) and adjust the geometry until it is optimised as measured by GPS performance testing. If you also have a non-standard exhaust this can bring some improvements by trial and error methods. This arrangement produces a lot of intake noise and this can sometimes sound faster when it is actually slower. All good fun if you like getting your hands dirty.

Excellent response and very informative roadster,thank you. I should have made it plain in my post it was the cone type I was thinking of but I was concerned about possible problems with engine management which is something I would avoid. I liked the idea of getting rid of the original air box but in the circumstances I will leave well alone. Again, thanks for you reply.

Great and informative response Roadster

Brads, you will get engine management issues to solve if you go for the cone type. The existing airbox uses an air pressure sensor to help manage airflow. If you don't use that you need to write it out of the ecu settings to stop the bike looking for it. You'll get an error code come up without it and this will usually affect performance.