CDI box, gains or losses?

[Jessem24]

a friend of mine suggested to get a cdi for added power. i never got one for my old 300ex and im ify on getting one for my 400ex. it is stock exept for nerfs and bumper but i am worried that the added 1000 rpms could do harm to my motor as well as advanced timing. i know almost nothing about these. info welcomed. thanks

[rideracelivemx7]

if you get a good quality rev box it deff helps out the spark from the higher energy output, if your worried about the extra 1000rmps then you should have blown your valves out the *** of your quad becuase then that means your always on the limiter, which isnt cool. if your good about your topend and reving, then its all systems go. i mean its not like its a 450 and nails the limiter in .2 seconds flat, you have to rev these things out with intention. we put a bbr revbox on my cusins beater crf230 and it did wonders for the bike, ill tell you that. just do your research

IMO unless you have a 440 stroker or something equilvelant your wasting your money. If you are getting a different ignition get MSD or Dynatek.

[bigbad400]

i just got the amr stg 2 coil and cdi combo from ebay and i love the snappy feeling it gave, i think it gave a good gain on low and mid, i stay out of the top end too much anyway so i wouldnt know about that. i got it to help the low end and improve throttle responce, it did more than i expected as far as the pair. a single cdi would be good to im sure but that combo sure packs a punch for price and, i would recomend it to anyone who wants to feel more snappy in the throttle, and gain some low end power

[DuwBra]

My cdi gave me a little more low end punch and the throttle is noticably snappier. It also made my quad start better, when I put it on my quad started in half a second. And I love the fact that i have more rpm up top. This stuff is all opinion and experience so dont think this is exactly how it is. This is just what I gained from my procom. Also all the stuff mentioned above is not like an amazing gain, they're small gains but noticable gains.

[buster024]

Whether or not to get an igntion box really depends on your riding. If you are riding wide open dunes, or long flats, then it will probably improve your ride. I noticed a distinct difference in the top end (not sure what anyone is talking about on the low end). I ride mostly trails, and so rarely if ever bounce off the stock rpm limit, but whenever I go WOT, I can tell I've got a bit more than I had prior to adding it.

[BigLuke]

Poweroll states that a factory XR250R CDI box will give a more aggressive timing curve and 800 more rpm on a 4hundy.

[brian76708]

you start losing power at higher rpms just look at dyno charts. not inless your motor is built for these higher rmps i think there worthless my $.02

[buster024]

Brian7678....have you ever had one on your bike? You may lose hp's, but you will pick up rpms (i.e. speed) at WOT. Without question, as a fact, my bike is faster (at WOT) with it than without it.

Now, that being said, I'm at WOT only once or twice a ride, so it's not really a factor during the majority of my ride.

Originally posted by buster024
Brian7678....have you ever had one on your bike? You may lose hp's, but you will pick up rpms (i.e. speed) at WOT. Without question, as a fact, my bike is faster (at WOT) with it than without it.

Now, that being said, I'm at WOT only once or twice a ride, so it's not really a factor during the majority of my ride.

you need to ride harder lol just messin. I ride WOT almost every time I go riding. Yeah I beat my quad but thats what its meant for having fun.

[buster024]

After I posted that, I thought a little more about it, and should probably clarify. As long as I'm in situations that don't demand extra hp's at the high rpms, the rev limiter can and will add speed. For example, if you are on a flat, a road, or anywhere where you can go WOT and not need to downshift to continue to gain speed. If I'm hill climbing, or powering through something, I'm not convinced the rev limiter does a lot. Maybe I'm wrong on that, but I couldn't honestly say I noticed a difference in those situations.
I ride at an area that takes a few mile blacktop road ride to get to the trail area. After I installed the cdi box, I was able to get to a higher top speed than before, and with my gearing versus my riding partners 450 gearing, I can pull him at WOT. BUT, that is mostly (probably 90%) due to the gearing versus the box.