I installed the K&N Oil impregnated air filter in my LS650. It gave me a noticeable mid to upper RPM power improvement. Also, I like its seal to the airbox much better than the stock filter. Beware of the following problems:

1. K&N didn't supply the holding bracket in the box. I had to get the motorcycle shop to pursue K&N for the bracket after having ordered 2 filters. The installation instructions showed the bracket, but it wasn't included in either package. ??? I did finally get the bracket.

2. A couple weeks after installing the filter I noticed the bike would not accelerate normally. Something was hanging up. It might accelerate properly in first gear, but wouldn't in second gear. Sometimes, I would hold the throttle wide open, and something would let loose and the bike would accelerate.
I removed the carburetor and inspected it closely. I found an oily residue on the piston valve and its bore. I cleaned the residue off these surfaces, and normal acceleration was back! The source of the oil was obviously the K&N filter oil. So, be careful with this filter.
I hope most of the oil has been processed through, and I won't have to take the carburetor apart again.

The filter was used right out of the box, after removing the plastic wrapper. No liquid oil was observed. No oil wad added.

By the way, I'm happy with the performance of the filter.

Our local automotive talkshow guru does not like the K&N because of the mass air flow sensor problems he has observed in cars at his shop. This is consistant to what you have heard. So be extra careful there.

My last car was a 1996 Mazda Miata and I did put a K&N on it and had no problems. I did see noticeably more power 4000RPM and above.

My new car is a 2006 Honda S2000. I'm going to wait a couple years for K&N to get it right for this car.

I got caught today in a speed trap testing out my cleaned out carburetor. Fortunately, I wasn't going fast enough to get a ticket. They gave me a warning and a lecture. Its pays to be respectful and humble.

I had something simular happen on my '02 when I switched to the K&N filter, noticed a little bit of oil on the bottom of the carb and some oil in the airbox. Freaked me out a bit cause I thought there was an oil leak. The exhaust also smelled bad, sort of like oil burning. i figured it was just a little oil from the filter getting sucked into the engine and getting burned. The smell went away after only ten miles so it wasn't any big deal. Still it was worth it although now I wish that I had gone to a cone filter just to clean up all the stuff behind the carb.

Rob,

FWIW, the reports of oil contamination was with "hot wire" type of mass air flow sensors.   The wire gets coated, stops working, and the EFI goes into limp-in mode.  I've read about this problem specifically with BMW 3 and 5 series cars.

Steve

Just put a filter on your breather tube.  Plenty of folks who've gotten rid of their airboxes and use a cone air filter use a smaller air filter on their breather tube.

Gulfstream wrote on 12/31/69 at 16:00:11:

No I don't, sorry.  I use a direct replacement K&N in the airbox.  There are several folks who have though.  You can probably find it by doing a few searches.  Set the way-back for something like 800 days though.  Maybe someone who uses it will chime in with the part number.

Gulfstream wrote on 12/31/69 at 16:00:11:


Well, there ya go!

Cone air filter