AirFilter Stock/K&N

Can someone explain this:

Running w/ the K&N I always hit the rev limiter in 2nd thru 3rd.

When I run the stock filter I "almost" never hit the limiter.

Mods include:
E-Series slip on
K&N Jet Kit-- 170 and needle with clip on 3
Got holes in the airbox lid too.

[330exracer]

the reason is your puttin more air in your motor. which makes more power. so you get to the rev limiter sooner

that makes total sense. so would a new cdi box like the WBrothers help any here?

[roostfrom250ex]

In other words, your going faster.

[Chef]

Yes, a rev box would help, but get a sparks or marcums, WB is junk, mine like shorted out or something and stopped working entirely...

cool.. I'll look into those boxes. So if I get a box to increase the rev limits on my quad, what type of cons go with that? Will I actually be over revving(sp) my motor or how does that work?

[NJ300ex]

The disadvantage is that your motor won't quite last as long and it will be harder to start in cold weather. This doesn't really matter though because it only damages your motor if you are always wide open for a long time and you live in california so it won't be hard to start because of cold weather.

[Bart]

With your mods, you should be shifting long before you hit the stock rev limiter. Just look at any dyno chart for a 400ex.

I guess I'll have to put one on to really find out. Honestly, when this bike was all stock I never touched the rev limiter. After the mods though this thing seems to go through the gears like a two stroke.

And just to make sure I know what I am talking about...... when the bike starts to sputter at the top of a gear, thats the rev limiter causing this right? I need a shift light!!!!

[Bart]

Sounds like you may be a little rich on the main jet. You may want to try a different jet before spending money on a rev limiter.

Everything I have read on the rev limiter is that it is a waste of money for everything but a full race motor. The 400ex power curve starts to drop off at 8000 rpms, well before the stock limiter kicks in.

Fred---> I'm running a 170 and I think I have a 165 in the kit... should I drop down, is that what you mean?

Yup,,,your chokin the motor out with too much gas..don't get the rev limiter,,you don't need it,,put the 165 in and I bet you'll be in good shape..

alright, I throw it in this weekend and see whats up.

Thanks Guys!

Rico/Fred---->

Dropping in that 165 jet was the cure...... I could definitely windout in 2nd and 3rd like it should. Thanks guys!