Whats the difference when it comes to aftermarket cdi boxes. Who makes the best one. I'm looking for my kfx 400. Thanks

 

Vortex and Dyna both make great CDIs. The CDIs priced around $100 don't make enough of a difference to make it worth the $$$, at least in my opinion. I'd recommend getting some motor mods first, at least a cam and stiffer springs. A good CDI will give you some gain with a stock motor, but it can't be fully taken advantage of until you at least get stiffer springs to prevent valve float, and let the engine breathe easier.

 

I'm planning on adding a ct racing exhaust and a stage 1 hot cam. Along with a cdi i think it will be a good combination all together. Thanks.

 

Stay away from the white brothers high revs i have one on my qaud and it is a pain in the @$$ to get started when its cold

 

hey i got the dyna cdi and it's the best thing i have ever spent money on as far as mods go.i'm running a mostly stock motor with a e series pipe....don;t recall what jet...it a real kick in the but just to plug something in and notice the power. i got the programable one for some reason but i have been afarid to mess with it much just for the fact i don't understand everthing.like recon said go ahead and buy a good one and skip those chepo's.

 

I bought a white brothers rev box for mt 05 for $40. i love that thing! its worth the $40 on its own because it eliminates the restrictive reverse rev limiter. i also noticed some gains. before i installed this product i could lift pull a wheelie going down the road in 4th, after installing this white brothers REV box i can now lift the front end in 5th gear. its hard to tell other than that right now because of the snow. i dont know where 430ex rider is from but i know that if its cold out 400ex's are a pain to start and they are notorious for hard starting in the cold weather, but they do start eventually... also with the mods he has on his ex im sure the higher octane/ higher compression doesnt help the starting when its cold... but if you have the extra cash laying around buy a good REV box. after you install all of those other mods on your ATV you will be happy anyways.

 

You can pull a 5th gear wheelie on a mostly stock 400ex? Somehow I really doubt that.