Has anyone bought the CDI box for there 400 yet? Any big noticeable improvements on the performance? Just wondering if its worth the money.

 

My wife bought it for me for xmas. I'll let you know after the 25th. My test will be good because my bike is mostly stock except for vented air box lid and some minor rejetting. Engine is stock and so is the pipe.

 

Well, heres how it works at least for me. I manages to get a white bros cdi real cheap from a guy at work (he found out whats happens to a 400ex when it rolls off a trailer at 75 mph). If your bike is otherwise stock, its a waste because the powerband takes a dive before it ever gets to the stock redline, i.e., its faster if you shift before you get there. I dont know the story with a aftermarket pipe only, because i installed a new cam shaft at the same time i piped mine. I installed a white bros race cam and stiffer valve spings, which did hurt the bottom end somewhat, but the rev limiter became extremly helpful because the motor now pulled like mad all the way the up, the rev limiter increase allows me to pull a gear farther about 1200rpm worth i think

 

I finally got it and put it on, its a must have performance add on.

 

bg400,

What other mods do you have?

 

00' 400EX
Complete Big Gun Exhaust
White Bros CDI Box
Dyno Jet K&N Power Kit
K&N filter with Precharger
155 main jet
Removed airbox lid
14T sprocket
Aluminum Skid Plates + Bumper
Just added 22" Mud Machines

 

BG400,

Thanks...I'm waiting for my supertrapp ids2 silencer, extra discs, and jets to get here before I put on the high rev cdi box that's sitting in my truck.