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View Full Version : Air filter question (K&N for adv bikes)



bart
29th October 2009, 20:49
I was just kicking the tyres tonight, getting the bike (DR650) ready for a ride tomorrow, when I thought I'd better check the air filter. Glad I did. Bloody air box was full of an oil/water sludge. Been riding in the rain lately, plus the odd river crossing.

I drained the air box and pulled out the filter. The bike came with a K&N jobby.

Photo 1 - shows the sludge

Photo 2 - I didn't have any aerosol filter oil left, and I'd recently bought a bottle of the foam filter stuff, so I carefully brushed this on. I that wise?

Photo 3 - filter refitted

Question 1 - is it OK to leave the drain plug thing off the air box, or is this asking for more trouble? (photo 3 lower centre)

Question 2 - are these K&N filters any good for adventure riding (extreme dusty conditions), or am I better off going to a foam filter?

Cheers,
Bart

marks
29th October 2009, 21:04
is this the first time you've checked the air filter? - you slack turd

the bike is rooted

buy a drz400

they are much better

fwiw I think a properly oiled foam filter is much betterer in dust than a k&n style.

see you at the petroless station at Ashhurst at 10.30 ish

warewolf
29th October 2009, 21:05
Drain plug open would have a minor effect on the airbox resonance. It looks easy enough to get to, and to see if it has murky fluid behind it. I'd just check & drain it regularly. Stick an extension on it maybe? Some bikes run a tube to the bash plate level, alongside the carb float drain & overflows.

I would say go with a decent dual-stage foam filter. K&N cotton filters flow 50% more dust than a standard paper filter... says so right on the packet. As such I wouldn't go near one on a gravel roads bike, and only fit one to a road bike that had the flow system improved eg an up-spec supermoto conversion, or my/jatz' Trophy which choked on the OEM filter after all the ports/valves/cams/carbs/exhaust work.

mossy1200
29th October 2009, 21:07
I would run a hose down lower to stop water going up the nipple though.

bart
29th October 2009, 21:18
Cheers guys. I'll get a double foam filter jobby on quick smart, and perhaps check it a bit more often.:whistle:

Don't tempt me Mark. I might bring the DRZ tomorrow............if I can get it started. Bloody battery's flat. Oh well, I guess I'll bring the black lard arse.

See you in the morning. Snow up Takapari........tempting.:cold:

NordieBoy
30th October 2009, 16:35
A foam filter will need the stock filter cage. Do you have that?

Easiest is throwing a filterskin over the K&N.

Padmei
30th October 2009, 17:31
Bart.

You're gonna win the Lotto tomm nite. What 1 adv bike would you buy? Really curious

bart
1st November 2009, 21:04
Bart.

You're gonna win the Lotto tomm nite. What 1 adv bike would you buy? Really curious

Ducati Hypermotard with a few mods :woohoo:

Or a KTM 690E

I found the limits of the front suspension on the 650 this weekend. Otherwise the DR isn't too bad. 460km of all sorts of terrain today.

bart
1st November 2009, 21:05
A foam filter will need the stock filter cage. Do you have that?

Easiest is throwing a filterskin over the K&N.

Good point. I haven't got the cage thing.

bart
1st November 2009, 21:09
Photo 2 - I didn't have any aerosol filter oil left, and I'd recently bought a bottle of the foam filter stuff, so I carefully brushed this on. I that wise?


THIS WAS NOT A GOOD IDEA.

Crap must be too tacky and clogged the filter. I had to remove the filter until I got to a garage to clean the gunge off.

Moral of the story - don't take shortcuts, and use the proper filter oil.

warewolf
2nd November 2009, 22:45
Moral of the story - don't take shortcuts, and use the proper filter oil.fwiw I made the same mistake the other way 'round: used K&N oil on a foam filter. The K&N oil just didn't want to stick to the foam properly. It beaded on the filter and dripped off - but I did put plenty on there to make sure it didn't all come out.

K slider
3rd November 2009, 11:29
Hi Bart I use DNA filters in all my bikes they work real well plus they gaurentee the horse power increase.