Sparks key or cdi ignition

[skank21]

I just bought a mint 03 400 from my boss for grand and I'm already modifying. The quad is 100% stock other than me modifying airbox and rejetting last night. I will be running modified or custom built slip on. The question is there any quality aftermarket cdis out there. Does the sparks key add enough to be noticeable?

Thanks

[cheater13]

Only decent one from others' reviews is the White Brothers CDI. They are very hard to find though. I have a Big Gun one and I didn't put it in yet. I'm going to see if the dyno shows any improvements for my build when we test it.

[Honda5]

You won't see much of a change on a dyno. But what you won't see is how fast you can raise the rpm. Find a place with some timing gates and do a couple dozen runs if you want to see the difference.

[2001400exrida]

the sparks key is very noticeable, but a little much in my opinion. best thing you can do hands down to a 400ex is put a different cam in there, that is a very noticeable gain.

[CJM]

Put the sparks key in a stock 400 (only other mod was lid removed) it honestly didnt do much.

Exhaust and stage 2 hotcam is what I would do, then remove the airbox lid and re-jet.

I tried a few CDI boxes, all they did was raise the rev limit and the powerband was very funny (like all power was in the upper rpm range). White bros CDI is the only one that worked right. Unless of course you wanna spend some coin on a dyna or sparks.

[2001400exrida]

when i put the sparks key in my 2007 it was night and day. those things make a noticeable difference you will feel quicker revs and you'll reach the rev limiter really fast, almost too fast for my liking. it is a 6 degree timing advance, if ya don't notice something didn't get done right. that being said it's a very cheap mod for the power advantage however if you try to run a cam and high comp with the sparks key things tend to get a little too hot. the key is a great mod for a stock machine, but as mentioned you're better off with a cam.

[400man]

I think I tried a srp +6 degree key after I first got my bike. it don't remember much of a difference though. I went back to stock when I lightened my flywheel cause I figured it would make it hard when setting the cam timing because of the offset of the flywheel and the timing marks.

a lightened flywheel is a noticeable mod and will let it rev quicker.

[skank21]

Will being running
152 main
40 pilot
Air box mod
Zx6 slip on (custom header adaptor)

In debate
Spark's key at $32 or
Dynatek cdi at $64

All other mods for me will be focused on a xc suspension

[RNL]

Have to agree, my cousin just did this mod to his 06 400 back around New Years. It really woke it up, more grunt and revved up quite a bit faster. Then he did a exhaust and ditched the lid with a rejet, and it's a wheelie machine, but just way more fun to ride. Six degrees in timing is a big jump IMO, and it should be noticed. I know we noticed it.

[RNL]

Did anyone that installed this key notice that the engine sounds different? Kind of strange question, but it just sounds different, I guess it's hard to explain.

[2001400exrida]

Have to agree, my cousin just did this mod to his 06 400 back around New Years. It really woke it up, more grunt and revved up quite a bit faster. Six degrees in timing is a big jump IMO, and it should be noticed. I know we noticed it.

Yeah, anybody who has actually done this mod and felt it knows good and well that it's noticeable. For the money it's a great mod, but does heat things up. RNL what other mods is the motor running, it may be that it's getting hot and could cause it to sound different.

[RNL]

Yeah, anybody who has actually done this mod and felt it knows good and well that it's noticeable. For the money it's a great mod, but does heat things up. RNL what other mods is the motor running, it may be that it's getting hot and could cause it to sound different.

It's all stock internals, just a HMF exhaust.

[2001400exrida]

oh ok yeah i wondered because they really recommend running it with stock compression only. That's why this key is so nice because the compression on the 400ex is low to begin with so when you advance the timing 6 degrees it definitely responds to that! not sure what kind of noise it is, but i'm sure it's fine if all you're running with it is a hmf pipe.

[RNL]

oh ok yeah i wondered because they really recommend running it with stock compression only. That's why this key is so nice because the compression on the 400ex is low to begin with so when you advance the timing 6 degrees it definitely responds to that! not sure what kind of noise it is, but i'm sure it's fine if all you're running with it is a hmf pipe.


Yeah it's not a noise it's making, like a click, thump, or grinding, the whole motor just sounds different. It runs great and it's not getting to hot, although it's still winter so hard to say. It's so fun to rip up and down the back roads on, feels almost as fast as my YFZ. Well almost haha