Which CDI to get?

[440_Turtle]

Im runnign a stock CDI and woudl like to add some more revs. whats a good, fair priced one that will last.

[02440exkid]

i have a magnum have not had any starting problems with it i think it was about $50.;)

I love my Big Gun Over-rev. It revs way faster then any other cdi that I have been on. But if you are looking at one under, about $60 then just go to bikebandit.com and order an XR250 cdi which only costs about $20. And that will increase the revs by about 800 but the big gun and other more expensive ones give you about 1200-1400 added revs.

[02440exkid]

It revs way faster then any other cdi??????

the motor depends on how fast it revs not the cdi

What are you talking about the cdi makes it so the bike can rev faster. Or why else would you buy an aftermarket one. It is not just for looks you know.:devil:

[02440exkid]

it so it can rev higher

Yes you are half right but it also revs faster.

[02440exkid]

o never new that sry

[esr250r86]

rotflmao! I just love this post.:D

Originally posted by esr250r86
rotflmao! I just love this post.:D
:mad: Stop ruining everybodies posts

[esr250r86]

Ruining everybodys posts, Im just trying to give positive input. I think your just a nasty.

[knelson]

It advances the spark timing slightly, and increases the rpm by 1000 or so.

Originally posted by esr250r86
Ruining everybodys posts, Im just trying to give positive input. I think your just a nasty.

Sorry about this guy everybody he is just a stupid old man that doesnt know what he is talking about. He gave me some bad info one time and made me blow up my engine. Do not listen to him. :mad: :grr:

[esr250r86]

He is the one playing, no more bashing. :)

Originally posted by EXking
Sorry about this guy everybody he is just a stupid old man that doesnt know what he is talking about. He gave me some bad info one time and made me blow up my engine. Do not listen to him. :mad: :grr:

alright jk everybody

[Honda2000]

I have a pro com engineering rev box. You may not have heard of them, but they did make the rev box for the white brothers kit on a yfz. It was 45 bucks on ebay!!

[440_Turtle]

anyone have any experince with the SPARKS RACING CDI?

[cals400ex]

Originally posted by 440_Turtle
anyone have any experince with the SPARKS RACING CDI?


yeah, it sucks. after owning a few different ones i would not get anything but a gt thunder.

[440_Turtle]

o'Well it should be here next week. Hopefully it will help my sick baby :(

[GPracer2500]

Pretty sure the Sparks is the same as the WB (and prolly a bunch of others?). I've used a WB and never had any problems. Plenty of people have reported starting issues with the WB though....I dunno, I often keep my battery on a Tender so maybe that's the difference?? Who knows....

What I find really irratating about nearly all the 400EX aftermarket CDIs (the high end Dynas, MSDs, etc. notwithstanding) is that no one seems to really no for sure what they do do the ignition curve (if anything). RPM limits are easy to detect but ignition timing changes are much harder to distinguish. I've spend some time trying to find answers but always come up short on facts....

A while back I started a 400EX aftermarket CDI "buyers guide" but abandon the project because I couldn't find enough info on each unit to be able to say how they are different. The manufactures I asked either never answered or didn't seem to know themselves what the details were....oh well.

[cals400ex]

if you just need extra rpms then the sparks or wb boxes will work. they both make the bike harder to start. now, we tested these in 4 different 400ex's. all of them where higher compression with larger bores. plus, two of them ran hotcams (no decompression assemblies). the other had a TC cam in it and that does have the decompression assembly. however, none of the batteries were like brand new. however, they had plenty of power to turn the bike over and continue to crank and crank. none used a battery tender either. in cold weather none of the bikes would start. if we swapped on a gt thunder or stock rev box all 3 bikes would fire within a few seconds. we never had any problems. one of the bikes was running a colder plug and it even was tempermental starting in 50 degree weather. the other two would start usually down to high 30's to 40 degree temps.....unless the stock or gt thunder rev boxes were on. then we could get them started in below zero temps. the sparks box might give a slight throttle response advantage over the stock rev box. you will probably have to know your bike pretty well to notice the difference though. however, it does not compare to the gt thunder aggresive curve box throttle response.

[7OahuEx]

Got a White Bros rev box from ALBA for about $70, adds about 1000 rpms to the limit. With stock box used to hit rev box from 2nd gear thru 5th, now i never hit the rev limit. Good investment, been running it for about a year without any problems....