K&N Outerwares jetting questions?

[07250ex]

ok i have a stock 250ex if i was to run a K&N filter with outerwares and the lid on would i have to re jet? leaner or richer? would it allow better airflow? worse? similar to with out a lid and i assume it would stay cleaner much longer then a stock filter with open lid correct?

[tedwilley]

I assume by 'stock' that you do not have an aftermarket exhaust.
If you leave the lid on, you will only slightly increase your air flow 'in', but your engine will breathe better.
Now, keep in mind that ALL of the newer quads are set slightly lean from the factory to meet emission requirements/
Any changes which increase air but not fuel will make your mixture leaner.
The outerwear, when clean, only slightly decreases airflow vs. just a K&N. Just check it regulary, because it will capture lots of dirt, especially when its damp dirt, but its easy to hand wash.
Your setup is listed in the Performance FAQ, start with Ryan's settings. Buy the recommended main jets for completely stock (98) and for your setup (100), move the needle clip down to position 4. Main jets should be cheap at the dealer. Unless you are running a full exhaust AND riding at a lot of different elevations you do not need to have more than a couple-three different jets available, don't spend $50-75 on a jet kit.
If you cannot tell ANY performance difference between jets, always go for the larger of any two jets. Spark plug reading is the best way to fine tune jetting. Do a search, its in at least two or three posts.
Jetting is VERY easy, too easy to blow off as unnecessary.

[450ERRRRRR!]

If your going to leave the lid on then add about 6 Uni-vents and bump up the pliot a size and the main to a 112 and it will run great.

[YFZ450Ridr]

an outerwears wont do much with the lid on but it will help. take the lid off and then rejet with the k&n and outerwears, cheapest easiest power you can get!