well my 420 rancher needs a new air filter and what i was wanting to know is do i have to have it retuned if i put a k&n or a uni on it when i got it it had a yellow foam filter on it not sure what brand got the bike used o i dont know i would like a k&n but dont wanna havbe to get it retuned

 

Keep in mind, less wind restriction generally means a bit more easy-air-intake, but less trapped dust upon the filter, and a Leaner fuel mixture.
And yes, you might cause you engine to run hotter, and so will say get a new fuel manager to go with it. Others will disagree for just for a airfilter change, but for me....I ride in dusty enviroments (don't you) and I dont want it in my cylinders!

Do you really need it you think?...I have found the Rancher 420 to be a screamer. If you need more, maybe consider tradin up to a different bike[img]i/expressions/face-icon-small-cool.gif[/img]

 

K&N's pass fine dust...I unfortunately know this from first hand experience!

I have the UNI on my 420. The FI can adapt to small changes in airflow, but large changes will require a remap. Remember, all quads run lean from the factory, so don't push it to far....

 

I'm in total agreement with Reconranger on this one (I can't belive I said that). [img]i/expressions/face-icon-small-wink.gif[/img]

I can show you a link where K&N was compared to stock paper filter in Duramax applications... The gauze type filter only held about 1/3 of the dirt before clogging compared to the stock paper filter, and the gauze filter passed like 18 TIMES as much dirt through the filter. To top that off, the K&N was slightly less restrictive than AC Delco when clean, but after a little time in the dust stream the AC Delco was least restrictive.

Paper filters don't do well in environments where they can get wet- so for ATV's a quality foam filter (like Uni) would be my choice.

 

UNI

 

I agree UNI.

 

Jeffin

Have you got any data or stats on the Uni filter?

 

The only independent test to ISO standards I have found was for Duramax applications. There, the UNI didn't do great...

http://www.duramax-diesel.com/spicer/index.htm


Longish article, but I thought it was very interesting.

 

<div class="FTQUOTE"><begin quote>Originally posted by: JeffinTD

The only independent test to ISO standards I have found was for Duramax applications. There, the UNI didn't do great...



<a target=_blank class=ftalternatingbarlinklarge href="http://www.duramax-diesel.com/spicer/index.htm
">http://www.duramax-diesel.com/spicer/index.htm
</a>


Longish article, but I thought it was very interesting.</end quote></div>

I have not read this in a very long time, but there is considerable speculation that the test filter was not properly oiled!!!!!

 

<div class="FTQUOTE"><begin quote>Originally posted by: bean_11_2000

well my 420 rancher needs a new air filter and what i was wanting to know is do i have to have it retuned if i put a k&n or a uni on it when i got it it had a yellow foam filter on it not sure what brand got the bike used o i dont know i would like a k&n but dont wanna havbe to get it retuned</end quote></div>

For some reason, the UNI for the Ranchers does not come with its own support frame....so you have to use the stock canister that goes inside the air filter, and it is way restrictive. That is probably more of a limiting factor than the filter itself.