The Zephyr Zone

After trying a K&N air filter on my commuter XT250 with positive results (eliminated the surge it had at higher revs, felt like it was struggling to breath) I decided to try one on the Zephyr 750.

Open the box and the first thing I notice is how misshapen the filter to air box seal is. Just poor manufacturing quality. As I was changing carby jets actually had the air filter housing completely removed from the bike. With the K&N filter installed and the lid on, there were sections of the seal where you could insert a feeler gauge where it doesn't even touch the housing. You would have been relying totally on a layer of grease on the seal to make it air tight. The grease would have been the only thing making a seal, so poor a fit is the rubber seal.

Basically, stuck it back in the box never to be used. Cleaned up the old foam filter, re-oiled, and refitted. Save your money, the K&N air filter is junk quality, IMO.

And I second that. Had this twice on diff bikes, simply didn't fit and I had to change the design a bit to make it fit (as there was no alternative). Sticking to OEM whenever possible now

I've been happy with mine on my 550. Can't speak to other models.

i was looking to get one of these for my 1100 , expensive option , especially if it don't fit proper ...

I K&N filter is about the longevity, not performance, as it is washable and reusable, so the initial cost is more because the stronger material. You would hardly feel any difference in performance....and in any case, the so called 'performance' filters like K&N with better 'breathing', they do so by simply FILTERING LESS, and have seen magazine tests confirming this.

If you poke bigger holes in in stock filter with a screwdriver, then you would get a "performance' filter, at the EXPENSE OF FILTERING.