I have been reading alot of the posts regarding K&N filters and jets. What will I gain just by replacing the stock filter with a K&N, aside from better filtration and more breathability? Having just bought a new bike, I don't want to start mucking about with the carbs or really anything else.

Some clarification would be welcome.

Thanks

 

You will gain a LITTLE more HP. Only about 1 maybe 2 HP max. That is probably even a "high" estimate.
Later,

 

I put one in my 2-stroke Sport and it made a huge difference. I then put one in my 4-stroke 2000 Kodiak, it made a little difference. With a 2-stroke, you get a lot better throttle response.

 

I bought a K&N for my '99 Sportsman 500 and I noticed a little quicker acceleration. I'm also able to reach top speed (52 mph) easier than with the stock filter. I feel it was well worth the $30 investment. I haven't done any other mods to the engine or clutch.

 

The K&N filters do allow more air through and thus can improve performance, but it's at the cost of allowing twice as much dirt through to your carb than a standard filter.

 

How do you figure a K&N filter allows twice as much dirt into your motor If they were that way then no one would use them. Just take your paper element and get it saoking wet once and full of mud and see what happens , I will bet you that you won,t be having it on when you get back to camp. They are in my opinion well worth the money.

 

I don't get my filter soaking wet!! Most engines do not run so well with water in them, K&N or not. I made a typo above. I meant the K&N allows 50% more dirt than a standard filter. K&N states their filter traps 97% of dirt. Most standard paper filters state they trap 98% of dirt. You might think this is a 1% difference and not pay any attention to such a small amount. Heres the problem with that. You don't care how much dirt is trapped by the filter, what you care about is how much dirt is let thru to your carb. The K&N filter allows 3%, the standard filter allows 2%. In otherwords, for every 2 grains allowed by the standard filter, 3 grains are allowed by the K&N. That's 50% more and if you think about it, it really is a significant difference.

 

Is that using a pre filter or a filter skin i use a filter skin and never have had trouble yet

 

I find that hard to believe. Oiled foam (like UNI)or cloth (like K&N) filters are some of the best air filtration devices known to man. Look at most heavy industrial motor applications that run in extreem conditions, they have oiled filter elements. Dry filter elements are easier to toss out and replace but not nearly as effective as oiled filters.
No matter how good your filter is, if it is not installed properly and air/dirt can get between the filter neck and the carb your done. This happened to one of my families farm tractors and after a month of running like that the engine needed a sleeve and ring job. Not cheap! I use some good quality water proof grease on the sealing edges of the filter to help seal out dirt, so far it has done the trick.

 

Look at the specs published by K&N, stating their filters trap 97% of dirt. Now go look at the specs for most standard paper filters. Almost all are listed as trapping 98% to 99%. Do the math and you'll see K&N's allow 50% more dirt to pass through. I'm not making this up!! This is from K&N's own published specs.