CDI box

[dbehr624]

Hey guys, my 06 450 CDI took a poop and I need a new one. So I have two questions... Will an 07 CDI work on an 06? And does anybody have any input on aftermarket CDIs? Thanks

-Darren

[davidl9999]

Yes, an '07 will work on an '06 (and vice-versa). However, for a stock CDI, I believe that the '06 is the preferred box. Vortex CDI's seem to be the unit of choice, but I have yet to use one. Plenty of threads on this.

[dbehr624]

I figured it would work as well, but I called the local yamaha dealer and their service dept said they are different. But I think I remember seeing the same part #'s for aftermarket CDIs for 06-08 450s. So I am very hesitent to believe them...

[davidl9999]

The maps are different between '06 and '07. The units themselves will work.

[dbehr624]

Okay, I think thats what is throwing most of these bozos behind the counter off. They kept telling me that they had different part numbers, but I told them that its probably because they are different maps not different housings. But thanks for the input, I appreciate it.

[grayracer513]

They are definitely different maps. You know how so many guys on here are always bagging the '08-'09 for being soft down low and in the middle? Well...

If you want to drop 4-5 horsepower at 5-6000 rpm, bolt an '08 CDI to your steering head and rage onward. An '07 won't be quite as bad, but still tends to soften the low end a bit. An '04 will work, but it will kill the high end just a little, and might give you more low end than you want. The '05 box just sucks, basically. Avoid it.

[dbehr624]

Oh, thanks! I was unaware that the years prior to '06 would work as well. That makes my ebay shopping even easier! ?

[dbehr624]

Another quick question... I have basically zero experience when it comes to electrical stuff, but i am wrong to assume its basically a plug and go procedure? or is a little more extensive to swap out the CDI?

[grayracer513]

Unplug one, plug in the other. Just shut the engine off first.

[elkjaer]

Gray: could you tell me why the 05 cdi suck?

i am a happy owner of a yz450f 05, and i think i runs good, never tryed newer or elder bikes though ?

[grayracer513]

The '03, and to a lesser extent, the '04 were broadly criticized as being too aggressive to be rideable by most people (the term "mere mortals" was used a lot). Yamaha "softened" the '05 with the timing map, but most people thought they went way too far the opposite direction with that. Some insist that they own YZ250F's that hit harder. The '05 CDI might be a choice for someone who wants a very mild, rider friendly motor, but not if you like a good amount of grunt in the mid range.

If you ever get to ride an '04 or an '06, you'll see what I'm saying.

[mdkcrf250r]

They are definitely different maps. You know how so many guys on here are always bagging the '08-'09 for being soft down low and in the middle? Well...

If you want to drop 4-5 horsepower at 5-6000 rpm, bolt an '08 CDI to your steering head and rage onward. An '07 won't be quite as bad, but still tends to soften the low end a bit. An '04 will work, but it will kill the high end just a little, and might give you more low end than you want. The '05 box just sucks, basically. Avoid it.

Dont know where you got these numbers but surely they are incorrect. You have any proof or is that just an estimation?

[grayracer513]

Dont know where you got these numbers but surely they are incorrect.

Why do you think so?

[elkjaer]

The '03, and to a lesser extent, the '04 were broadly criticized as being too aggressive to be rideable by most people (the term "mere mortals" was used a lot). Yamaha "softened" the '05 with the timing map, but most people thought they went way too far the opposite direction with that. Some insist that they own YZ250F's that hit harder. The '05 CDI might be a choice for someone who wants a very mild, rider friendly motor, but not if you like a good amount of grunt in the mid range.

If you ever get to ride an '04 or an '06, you'll see what I'm saying.

Well, would i be possible to mount a 06 cdi on my 05. and where could i get one?

i feel like it has alot of power, but as i said before i never tryed any other 450's ?

[grayracer513]

As far as I know, yes. You can buy one new if you like, or try to find one on eBay. But they've gotten very popular with the '08-'09 crowd, so they are pricey and hard to find. If I were you, I'd try to find the '04.

[FiremanKay]

Grey do you know of anyone trying an 04 CDI in an 08-09?

[grayracer513]

No, but it's a thought I've had. Not sure how it would work, exactly, but it's interesting. Might flatten the top end, or the tendency that the '04 had to run flat early may have been due to the cams it had.

[ttr250dude]

Gray, is it literally a 4-5hp loss? Or is that an estimate?

[mdkcrf250r]

Why do you think so?

Cause that would be quite a dip.

[grayracer513]

It is quite a dip. Most slip-on exhausts (it doesn't seem to matter which one very much) will add between 5-7 hp by actual Dyno readout on an '08, but only in the range between 4-6500 rpm. The CDI is worth about half that. I did see a dyno run on this change, but there were things about the way the test was run that made it less than totally scientific. But a ride on another bike did seem to bear out the results.