Bike mechanic did not recommend K&N air filter?

**paturoa** · 11th September 2012, 19:25

I took the strom in for a valve shim check and plug change on Monday morning. I gave specific instructions to not do anything else. Good workshop response was to quizz me on some other stuff (which I said no to) including an air filter change while they were in there. I said that I was going to get a K&N.

Later that day when I picked up the bike the mech had obviously been talking to the person that I talked to that morning (another good sign!), and said that I shouldn't get a K&N as the paper based filters are much better, and that in his experience K&Ns let fine dust particles through and ferk the motor.

I've not heard this before, what say you bunch of keyboard mechanics?

**Madness** · 11th September 2012, 19:42

On a bike-specific forum that I frequent the members overwhelmingly rate BMC air filters over K+N. Fitment is one of the reasons but the K+N doesn't offer anywhere near the performance gains the BMC do on dyno tests.

**dogsnbikes** · 11th September 2012, 19:45

Yes have been told that in the past and seen difference compared to other filters....

I use Pipercross filters and don't get the dirt on the inside of the filter like I use to on the K&N Filters

**paturoa** · 11th September 2012, 19:51

Originally Posted by Madness

On a bike-specific forum that I frequent the members overwhelmingly rate BMC air filters over K+N. Fitment is one of the reasons but the K+N doesn't offer anywhere near the performance gains the BMC do on dyno tests.

This was more about not stopping the dust rather than performance / dyno.

**paturoa** · 11th September 2012, 19:52

Originally Posted by dogsnbikes

Yes have been told that in the past and seen difference compared to other filters....

I use Pipercross filters and don't get the dirt on the inside of the filter like I use to on the K&N Filters

Pipercross - Not heard of them before, I'm off to google that. Is there a local supplier?

**Madness** · 11th September 2012, 19:53

Originally Posted by paturoa

This was more about not stopping the dust rather than performance / dyno.

Sure, maybe it suggests that there are other options out there.

Still got the couch?

**steve_t** · 11th September 2012, 20:01

I used to use K&N in my cars but I've had multiple issues with oil getting through and on to the MAF sensor. I've gone back to paper until such time as the new car gets a MAFless tune

No such issue with bikes. Filtration vs flow is always going to be a trade off. I guess the question is whether the really fine particles that get through are going to do any damage over time, eg to injectors, or if they'll just get vapourised in the combustion process or pass through. I'd expect that if there was a proven link between K&N filters and engine damage, the US guys would have sued the pants off of K&N ages ago.

**paturoa** · 11th September 2012, 20:08

Originally Posted by Madness

Sure, maybe it suggests that there are other options out there.

Still got the couch?

yeah, you want them??

http://www.kiwibiker.co.nz/forums/sh...an-cave-chairs

**paturoa** · 11th September 2012, 20:13

Originally Posted by steve_t

I'd expect that if there was a proven link between K&N filters and engine damage, the US guys would have sued the pants off of K&N ages ago.

I've just been reading the manufacture's sites (dicing with BDOTGNZA with that apost'fe) and 2 of the above brands said better than OEM paper. I'd imagine that a nice clean cotton washable freshly oiled could be.

The question for the thread / me is that a real world nz mechanic volunteered with no benefit to himself what he has seen and said don't.

**Madness** · 11th September 2012, 20:22

Originally Posted by paturoa

yeah, you want them??

Nah, thanks. I actually lied about getting rid of mine to the carload of islanders. It's still here and is smelling more like a dogs arsehole every day.

**paturoa** · 11th September 2012, 20:30

Originally Posted by Madness

Nah, thanks. I actually lied about getting rid of mine to the carload of islanders. It's still here and is smelling more like a dogs arsehole every day.

So you know your couch smells like your dog's arsehole. I'm now worried that you are familiar with the smell of your dog's arse!

**Gremlin** · 11th September 2012, 20:32

OK, so the pure simplicity of a filter is to block bad stuff, let good stuff through... Ergo, the more air a filter lets through, the more air gets to the engine etc. Now, the trade off is that it's going to block less stuff right?

So, the question is, how much to block, how much to let through. Many do say that the aftermarket types do let through dust (engines don't like dust of course) however, I have a K&N and the air box behind the filter looks clean and shiny. This was when I pulled the air filter out and had to knock it against the ground to knock all the dirt off it...

Other option is to look at unifilters...

**paturoa** · 11th September 2012, 20:37

Originally Posted by Gremlin

Other option is to look at unifilters...

More googleing required, unifilters?

EDIT: ah http://www.unifilter.com/

EDIT 2: LOL, their catalogue page shows a number of bike categories, Dirt Bikes, Street Bikes, Vintage Bikes and an entirely separate class of bikes .... Hogs.

EDIT 3: But no Strom filters.