If I add a k&n air filter to this bike to let it flow more air to the engine, Will I have to rejet the carb to keep it from burning too lean ? I know when you add more air you have to add more fuel to keep from burning too lean, but is just a k & n enough added air to have to add more fuel ? anyone know the weight & H.P. of this machine?

 

I didn't rejet on my Sportsman, u should be fine.

 

With just a air filter you should not have to rejet. Although if you put on a free flowing exhaust then yes, you will.

Last I looked they way 415 pounds and in mag test it put out 44.6 whp.

 

are you talking about a different pipe than the white brothers pipe that it came with ? anyone knows what a 400ex is in H.P. & weight ?

 

nope I have the same White brothers pipe as you do. I removed the spark arrestor and the quiet core. Nice and loud plus it seemed like it gain a little power up top.

Not sure on the 400ex.
I wouldn't even worry about the 400ex's and the z400's with this bike fast wise. Look towards a Raptor-700, and the 450 sport bikes. Yes this 500 is fast!

 

no u dont have to. they come from the factory already rich. the filter is not gonna make a HUGE difference so i wouldnt worry about re-jettin until u strat doin other mods.