CDI Box, is there a way to make it work

[knighttime]

Well the WB unlimited rev box works great, and makes it really fun to ride, but wont start the mofo when its cold. I think having both the stock and hot box connected by a relay/toggle switch would work. That way u have the best of both worlds. I looked and there are a bunch of wires connected to the cdi box. But I do think this could work.

[Chef]

how did you get a WB Unlimited rev box? as far as i knew they only made the 10200 one???

[mikeboone]

Increase your pilot jet to a 42 or 45 and it will start much better hot or cold. I would forgo the idea of 2 cdi boxes.

[stevengates45]

Hmmmmm. If you could get it to work it would seem to be pretty neat i think! I just got my stock cdi box modified to not let mine cut out & it gave my bike lot more power & i dont have a prob at all startin my bike up even with it cold & no choke. Only thing with the toggle switch is because of all those wires you'd have to have alot of switches!

[Jekyl_22]

Does the CDI box give you more power, or just let you rev it to higher RPMs?:macho

[Sandragggen]

HOTT440EX...Check out Marcum, they have them. I'm thinking that they could be potentially harmful to a motor (missing a gear). I've yet to hit the limiter on my 440 with the XR250 cdi box. If you are getting close to the 10200 rpm level you will be way out of the power curve anyway.

You should be able to run both the stock cdi and the wb cdi if you install a MDS change over switch you can buy at any auto parts store. about $85. Below 50deg. the wb cdi will not allow me to start but the stock cdi will. Has anyone tried usng one of these switchs???????

[James70214]

stevengates45 who modified you stock cdi? How much was it and what did they do to it?

[stevengates45]

Guy over here by the nick name of Speedy. He charged me 60 for it. He drilled a hole in the center of it & filled it with some white stuff or somthin? :confused: Anway, it works & lets me rev way higher so im satisfied! :cool:

[shook]

The white bros. box has to turn the motor about 50rpms more to make your ignition fire in the cold weather its hard for your bike to turn that many rpms to get it to fire Ive heard that TC racing has them that you only have to turn them the same as the stock cdi. so it wont change it from stock and it will start in cold weather if anyone has tried the tc box give us some input on how it works in cold weather.

[badass400ex]

does the xr250 cdi box start in the cold?

[Sandragggen]

XR250 cdi box does not start in the cold. What I do is put stock cdi to get it started then once warmed up put the XR250 cdi back in and I'm ready to go.

I have the w/b cdi & have had the same problem. I installed the JE416 kit with the XR cam last week & took it to the dyno with bothe CDI boxes for a test. Ther was no HP gains with the w/b box and at the rpm where the w/b box helps the power curve is already in a flat line. I put the w/b in the toolbox for a spare.

[Sandragggen]

I agree with you 6969..no increase in hp. What I have found with a higher reving cdi is that it will put you back in the game with a mis-shift or a out of the hole sand spinnage. No rev limiter sputtering. Short shifting is where the Ex shines but sometimes a little more rpm's will help out in those not so perfect shifts.