Uni air filter vs. K & L

Hi guys. Check this out:

When I got my 1986 VFR 750 I put in a K&L air filter at someone's suggestion and the bike seems like it ran fine for two years. Well I had some work done this spring at a local bike shop in Madison and they suggested that I go back to stock on the air filter because everything else on the bike is stock. I put in the UNI filter today. When you examine the UNI it looks totally different than the Honda filter. The UNI simply uses a very open looking foam element while the K&L has that nice, dense reinforced cotton weave surrounded by a soft rubber base. The UNI looks cheap, with a hard plastic body (leaks?). Also, I took out my old Honda filter and it looks much more similar to the K&L.


Anyway, the bike seems to have more hesitation and a louder sound coming from the motor now. What the hell? I think the UNI has more airflow than the K&L. I'll be putting the K&L back in tomorrow but I wanted to tell people about this and also see what other people's experience was.

 

I am guessing you mean a K&N filter?? The only K&L I know of is a company that makes tools.

 

(1) i really think you mean K&N.

(2) comparing UNI and K&N, which are both aftermarket air filters with aftermarket filter elements, the K&N will always come out on top

(3) what kind of idiot in a *shop* would tell you to go back to a STOCK air filter?! id seriously re-evaluate my decision to let those people work on my baby.

(4) an engine is nothing more than a glorified air pump. the more air and fuel you allow into the motor, the more power it will inherently make. going with a more restrictive air filter impedes this air flow, and robs your bike of power. stock == bad, K&N == good.

find yourself a good K&N filter, get it back into that airbox, and if you want even more airflow into the motor, you can take the snorkel off the airbox, which gives it a neat little growl when youre down into the throttle really hard.

 

The only reason I would see them saying, "go back to stock" is sometimes when you add a K&N filter, much like and aftermarket exhaust, you may need to jet the carbs.

 

well i found the k and L filters hard to find .. but i like the uni in dirtbikes, in street i put Kand N in all vehicles if i have the money..stock filter are crap paper don't use them.. good luck in the air filter hunt...:thumbsup:no sir do not need to rejet for an airfilter..

 

more often than not, you can get away with a set of slip on mufflers and an aftermarket air filter without having to rejet the carbs, but thats about the MOST that you can get away with. any more than that (ie a 4-2-1 exhaust, or drilling the airbox, etc) and you will definitely need to rejet the carbs.

 

correction

ok, I meant K&N, sorry.

What I'm saying is I believe the UNI filter allows for MORE airflow and I don't want this because the bike is stock. The foam used is very open celled. I blew some air through both the K&N and The UNI and the UNI seemed to offer almost no resistance compared to the K&N's dense cotton element. This leads me to believe the bike runs LEAN with the UNI. It's a totally different design than the Honda filter, that's why I'm wondering why it's called a direct replacement for the stock filter.

disclaimer: The motorcycle shop guy who suggested the UNI was NOT a mechanic but the guy who works the front counter. He suggested the UNI when I brought the bike in and I agreed to it but for some reason it was not installed by the mechanic. I just tried it out for kicks.

 

I used to spend time on the VW TDI forum, lots of smart guys there who work for oil companies and the like, and folks who tear down and examine engines for a living. Their opinion of K&N was that it flowed more air than a foam filter, and more dirt too. The general opinion over there was not very friendly to K&N. They even liked paper better than K&N. But those guys are interested in getting a half-million miles out of their engines, so maybe their focus is different!

I've got a K&N on my bike, installed by the previous owner. It doesn't use as much filtering area as it could, probably to avoid the need for re-jetting (as I think I read around here somewhere). So it probably flows pretty much like stock. Seems like the reason to put a K&N on is not for air flow or for excluding dirt, but just to get 50,000 mile filter cleaning intervals. Install & forget, more or less?

 

well the truth is in your plugs if you think an air filter will lean out the bike with stock exhuast, check the plugs, but the k@n properly oiled catches the dirt and allows more air , a unoiled uni; they do oil them on dirt, race teams do not becuase they rebuild their engines everyrace!!!!!! street oiled filter for all conditions is the way to go, i have had several bikes, thats all i use and never had to rejet for an airfilter....in any motorcycle ever!!!..........in fact a road race bike doesn't use a filter,due to the fact stock exhuast can only flow so many gasses out when upgraded exhuast reduces back pressure then a rejet is required ...good luck and if you are paranoid go with stock paper.....