Probably depends on how "spot on" your present jetting is.

I had to. My bike went from (stock) lean to dangerously lean with the UNI.

If you run rich like a lot of KLX owners do - then no, a rejet will not be necessary.

If your right on - then a filter change can probably be absorbed without a change, but may also not be felt performance-wise.

 

That's the problem with where I ride... after the ATVs get done with the dirt, it gets transformed into a extremely fine (talcum-like) powder. You could shove buckets of that stuff through a K&N all day long.

 

I like Uni's dual layer foam. I have one in the KLX and KLR. I wouldnt use a K&N for any off-road environment. It would let too much past. I would use a K&N for a street motorcycle though. I use K&N's in my trucks and cars.

 

I'm running the K&N in my 99 Dodge Ram 2500, its awesome!

 

You guys are stoned. There's a reason all those desert trucks run K&N filters.

 

You mean the ones that get rebuilt after every race?

 

Yea.... Race application and hard trail riding reliability for 10+ years are completely opposite....

How about these? They dont have air filters at all....

 

from a guy who lives in a desert, I would not recommend any of the oil bath filters such as k&n if you want a vehicle to live a long time and be reliable. Keep in mind most of the filter oil moves on the filter over time, down to the bottom of the filter (gravity), leaving large parts of the filter unoiled. Those filters without oil allow many, many, many particles to get through without issue. Unless you want to re-oil your filter every few weeks, then they work great.

For a racing application they work great. Freshly oiled within a few days of the race and will be cleaned/re-oiled before the next race. More concerned with providing more airflow than extending the engine life.

 

I got a UNI a few weeks ago. I thought it would be good to have an alternate for the stock. Just keep one clean and dry, so I can switch and go if I have to. I'm not looking for big power gains, etc. After reading this thread, here us what I've learned:
The uni us junk,
k&n might be ok,
I have to rejet,
uni is the way to go,
oil my uni every few weeks,
no need to rejet,
No noticeable power gains,
uni gives as much power as a Klx 300 pipe.

I'm glad that's clarified. ;P

 

Maybe you should next ask what type of motor oil is best .