My buddy has a 03 Z 400 with yoshimira exhaust, k+n filter, and of course its been re jetted, Question is what rev box is the best one, as he keeps hitting the rev limitter.

 

stay away from those...nothing but trouble

 

Aftermarket CDI's are nothing but trouble? Why is that?

I am curious why? I have an '04 Z400, and after i get my new Yoshimura Pipe installed, and rejetted, i was going to start looking at a new CDI... But maybe not if they are 'Trouble'.

 

I know it's kind of pointless to get a rev box if the motor won't make any more power at the higher RPM's.Generally you would want to change the cams and then the rev box so that there is power being made at the upper RPM's.

 

HAHA! Thats like saying..."Stay away from those handguards...nothing but trouble"

A new CDI is possibly the easiest and one of the most beneficial mods I have done, but I got the Dyna which also has adjustable timing curves.

13inc- You are right, most Z's DON'T make power at those high RPM's, but it is beneficial for situations such as climbing a hill that you really have to rev out in 3rd to get up, because you don't have the torque to pull it in 4th. That's where you might meed these extra 1000-1500 RPM. Or if you are coming hard into a corner in a race, rather than having to shift up, just take her to the limiter and go from there.

Hard to explain, but it really is a worthy upgrade...

 

^^^^ I agree^^^^^

 

Make sure you redo your valve train meaning: get stronger valve springs otherwise you'll float your valves and that is BAD. Also if you want get the most out of your high revs, get cams so you can adjust and fine tune where your power is.

later
Superstar

 

exactly how i would put it, seeing what you have now, its not worth it, come back when you have a cam and springs.

 

once you get more mods then get a CDI. IMO

 

Thanks guys I'll print the posts listed here for him.