high rev-cdi box?

[mudlitecon]

does anyone have one on their bike. Can you tell a big difference? I have an exhaust, filter, and jet kit, so would it be benificial for me to get one?

[LazeR]

this is from the technical articles! Mickey Dunlap is the one answering the question

knighttime asks;

Does modifying the rev box or using a White Bros. rev (cdi) box increase performance on a 400ex? I have the 416 kit with an XR cam; would it help then? Also, my quad won't start when cold if using the WB rev box. What's up with that? Thanks for your help!

answer;

I believe the White Brothers black box and other companies use XR250 boxes which will have a slightly different advance curve for a smaller, higher reving engine. Personally, I have not seen that big a difference between this and a stock box that has been modified and the rev limiter completely removed. One of the reasons I might not have seen a difference is because I build bigger 500cc motors that would not benefit from the different advance curve and if we do change the timing, it's done on the fly wheel key. The XR250 boxes need the engine to spin faster at start up to trigger the ignition coil. When it's cold out or when the engine is not jetted correctly, this will add to the problem. With a stock box that has been modified, this is not a problem. In cross-country racing we want the engine to start as quick as possible because of the dead engine starts and the hole shot is extremely important - this is one more reason why we use the stock box. I can't answer your question whether the 416 with an XR cam will make a difference or not. If it does, it's very little.

[TC426EX]

You would see an advantage man...

stick to the TC box or the GT Thunder...

[MIKE400EX]

Don't think anyone makes one for a Recon.:confused:

[mudlitecon]

it's not specifically for the recon but, for the 250ex

[MIKE400EX]

Don't know of one for the 250EX either. You could advance the timing with an offset key though.

[mudlitecon]

they make one for the 250ex, i found it a dirt-deals.com under electronics

[bradley300]

hondas usually make peak power well before the rev limiter anyway so a rev box is useless. on the otherhand, once you go into the motor and start building something that revs higher than stock with a cam and bigger piston, a rev box should be a good mod