how much more power

[skater1107]

I have an all stock 2004 400exbut i am ready for some upgrades i have a full yoshi pipe stage 2 hot cam alumminum air box this one
http://www.insaneperformanceatv.com/400ex.html
with the little cowl top on it and a k&n filter inside also a jet kit but i have no idea how to go about jetting my bike how do i know how much bigger to go any help will do so how much more power do you guys think i will get noticable or not so much

[zrpilot]

I think the horsepower gain they claim would be gained by simply running a no lid set up on the stock airbox.

However if your looking to re-locate the battery, then it may be a nice airbox..

[Joe400ex]

Originally posted by zrpilot
I think the horsepower gain they claim would be gained by simply running a no lid set up on the stock airbox.

However if your looking to re-locate the battery, then it may be a nice airbox..

[mgraff400ex]

what brand of jet kit did you get. I know the dyno jet comes with instructions that give you a basic starting point based on what mods u have done.

When i put the cam in my bike before it was bored it opened it up quite a bit probably a 4-5mph top end gain but then i started hitting the rev limiter so take that for what it's worth

[Def-e-nition]

Run the Bike on a Dyno .
Guess this and guess that - its still guessing .

Once the bike has gone on a dyno - you have a reference point .

My bike ran 14:1 lid on with a 150 .
I then asked him to run lid off for me , and we got to 165 , still running 14:1
the reason why we both agreed on such a high a/F ratio was simply to counter for when the filter starts clogging up . it'll make the bike run richer .

so spend the extra bit , so you know for sure what the bike is going to do . That way , wehn the cams and stuff fall into your bike , you wont be doing so much guess work as far as A/f is concerend . the wrong A/f can Rip you a new ringpiece if the motor goes ...

[skater1107]

i dunno wjy but my bike now is all stock other then my full yoshi pipe and if i take off my air box lid it bogs big time

[Def-e-nition]

Your jetting is incorrect .