K&N Air Filter

Applications: Tested here on the Suzuki RM-Z250

Price: Prices may vary

Rating: 9

What It Is: This airfilter is the first one to come from longtime automotive airfilter manufacturer K&N, and is made from the same material as car airfilters, rather than the foam of traditional motorcycle airfilters.

Hits: For the low price, installing this filter is a no-brainer. Out on the track we noticed an immediate difference in power delivery, and at times it even felt as if there was an aftermarket exhaust system on the bike—it was that good. The filter added more bottom-end and top-end power, and for the bike we tested with—the RM-Z250—this was a much needed and welcomed change. As for durability, we haven’t had any problems yet, although we do recommend greasing up the rim of the filter before installing it, as this will help keep dirt from slipping past.

Misses: While the performance gain is significant, installing the filter was quite a chore. After removing the subframe, disassembling the airbox, and removing the backfire screen, we had logged in a whopping two hours in the garage. It wasn’t something we are used to when installing a simple airfilter on a bike, but we feel it’s worth it.

The Verdict: While it is a little bit of a hassle to install the filter, the work is well worth it. We loved the power increase out on the track, and for the money you can’t beat it.

Call 951/826-4000 or visit www.knfilters.com