"He told me to avoid any quad with a K and N air filter, because they kill top ends."

I wonder how much of the problem is idiots who install k&n filters without rejetting their carbs? Think about it. Joe Idiot hears that k&n filters give you more power. So he buys one slaps it in (possably doesn't oil it) and starts his quad. 30 seconds later thinks 'Holy crap those things work great!'. What happened? Well he just leaned out his fuel mix which WILL make your quad run like its hair is ablaze and it's *** is catching. 6 months later his valves are burnt, his rings are melted, and he has a hole in his piston. Did the k&n kill his quad or did stupidity?

Also, k&n is the most popular brand name for performance filters. People will say they just bought a k&n no matter the brand/type they actually purchased. I wonder if the mechanic was being specific about k&n or if he ment performance filters in general?

 

Just guessing he was probably being specific about K&N filters. At least I am on the two fairly new Sportman 500s I had to rebuild! Yes,they weren't maintained,could have meant a big difference if they were,but when you tear a machine apart and find dirt in the intake manifold,then piston seizure and scored up cylinder walls,you tend to shy away from em. Even an Uni filter if dirt packed will just run crappy from lack of air,but in all the UNI filter's I've dealt with,I've never been able to blame them on any engine failure and I've cleaned/serviced dozens and dozens of em over the years.We sold Polaris,Ktm,Husqvarna,Husaberg,among others. The same type filtering foam used in most of these dirt bikes. Again just my old OPT

 

Okay, I'm not big on performance mods myself, but I have seen may people say they had a k&n when they didn't. I was just wondering if the mechanic he spoke to did the same. But if they are as bad as you say probably not.

My 'quad' only has 3 wheels and best I can tell (PO filled vin with paint when he painted it "camo" it in 80 model Honda ATC 185 other than tires and the plastic fuel tank I believe it to be as stock as any machine 30 years old. I don't need performance mods. If I would get off my butt and change the clutch I would resume the search for a mud hole capable of getting it stuck (searched for it between october of 2011 and mid summer last year and never found one).

 

I've used many K&N and foam filters and would not hesitate to use them again.

 

Benn useing them for three years now no problems so far but do change
it pretty regulary have three and rotate them every ten hour's or so.

 

I agree with the mandatory use of a outerwear on a K&N.
I agree that maintenance is the key word.
What needs to be asked is:: Why use a K&N if you are not needing high rpm's?
Race tracks/dunes have dust. Dust has fine particals. The pro motor builders say that fine particals cannot be kept out of the motor with any filter.
I'd stick with the foam. I have and use K&N's, I also put pistons in. I accept that cuz I want the high rpm's for TT racing.
Curtis Sparks (and I'm sure others) sells a thick foam pre-filter to go over the stock foam filter. I talked to Curtis about K&N's. He said: "they'll learn after a cpl pistons".

 

What foam filter would be the best to get?

 

"Curtis Sparks (and I'm sure others) sells a thick foam pre-filter to go over the stock foam filter".
I'll stick with that.
I also think a foam filter oil is mandatory.
I use Bel-Ray. It's thick. Stick the filter in a gallon baggie, add oil, mix thoughly.
I've also used 10-40.
As usuall, it's all about keeping them clean.