No discs on white brothers

[William400ex]

I have a 2000 400ex with a white brothers slip on I want to take all the disks out and just run the cap. I also want to take the airbox lid off. Will I need to change my jetting if so what size jets???

thanks William

[hondarider2006]

when I just took my disks out, I didn't re-jet, but when I took my lid off I went up on jet size. What are you at right now?

[dirtmomma]

I'm just curious why would you take ALL your discs out?? J/W what does this improve?? WE run ALL of ours in our 400 :)

[300exOH]

You will most likely gain a little power on the top end by removing the disks but you'll lose some bottom end power. It may also be much louder without disks. You may want to go up one or 2 jet sizes.

[sharkinthepool]

When you run NO disc the noise level increases tremendously. Also the back-pressure is gone off your motor. We have two guys that actually chopped there pipes down and run a "duck-bill" or a turn down on the back of theirs. The chop down is do to the landing from jumps. If you are aggressive and "go for it" all the time you will eventually bottom the pipe into the brake disc.

As for the rings, if you remove your rings and your lid or even install a GT Thunder intake grommett you will most def. have to re-jett. If not you will get a lot of popping and cracking when you let off.

Not to mention a ton of flame.

That is not good

[MY450R]

dude all i got to say is that is dumb your going to lose power and itll be louder thats all
ive tried every diffferent configuration with that dumb ***** pipe and found that its best with about 4-6 discs in it
believe me if you go take them out you WILL lose power

[hondarider2006]

Originally posted by MY450R
believe me if you go take them out you WILL lose power


so your saying that running an open end pipe, like a HMF...TC shorty, whatever is open end, you are gonna lose power? Because running the wb e-series with no disks in the same thing brotha.

[Steve-o 400EX]

Here's the deal with the e-series and no discs, it will lose bottom end, it will gain a little top end, but without motor work done i dont think u will like it. I have a 416 and run a slip on e-series with no discs and it works out a little better with the larger bore and upped compression. It is also much louder like this, for a stock quad i would advise keeping them on.;)

[FatBoy Racing]

If you want to increase flow, why not just add some discs? I added a couple on mine and got good results, but I did have to get longer screws. In any case, that pipe eventually exploded and I've since switched, but I too think you won't get the results your after by getting rid of them altogether.

[William400ex]

I went to a local mx track this weekend and a huy with a 426 was running no discs with the cap it sounded good and was wondering if it youlw be ok on my bike.

[FatBoy Racing]

So he's running a modded motor with it wide open, but he may still be flowing too much. In any case, assuming your motor is stock, I'm thinking there's more to lose than to gain by opening it up all the way like that. My recommendation to you is to add discs one at a time until you feel the most gain overall, when it starts to dip, take the last one out and run with it. The WB and Supertrapp disc system is adjustable so each user can find the 'sweet spot' for their own bike. Take your time to find the best setup for yours. Don't make the mistake of assuming that what somebody else is doing is really the right choice.

Have fun!

[Steve-o 400EX]

Personally i agree with a lot of the things FatBoy Racing is saying. I would only recommend running the e series with no discs to people with slip ons on a modded motor with a top end cam, its the only way u will like the results of this change, it makes it a he!! of a lot louder though, which is an issue for some riders.

good luck:macho

[sharkinthepool]

You should not run it open.

Get you a duck bill for it, turn doen. From White Brothers. It is about $30.00 and it would be better than running it completely open. On a stock motor you are going to cause more harm than good.

[hondarider2006]

Originally posted by sharkinthepool
You should not run it open. On a stock motor you are going to cause more harm than good.


How so?? Its no different than running an open end slip-on, that has no disks. I still do not see how it won't hurt a modded motor, yet a stock one it will.

[Steve-o 400EX]

with a worked motor, like a 416, u have upped compression and a larger bore size so the motor is bigger in a sense, it can also handle more rpms with the stage 2 cam, at least on mine. I believe that is what he is trying to say.

[hondarider2006]

Originally posted by Steve-o 400EX
with a worked motor, like a 416, u have upped compression and a larger bore size so the motor is bigger in a sense, it can also handle more rpms with the stage 2 cam, at least on mine. I believe that is what he is trying to say.


Yes I see what he is saying about the 416, so the motor is bigger, what does that have to do with what it can handle? Its just letting the motor breath better, bored out or not.

[sharkinthepool]

What I am getting at is the larger bore motors (416, 426, 440, 450, and the 473) are designed to breath easier! They are designed for lots of let off.

Unlike your factory engine. It is designed to run the way the factory saw fit. With compression and back-pressure at a balance.
Made to last and make the buyer feel this is a good company and that is what I should buy the next time.

[Steve-o 400EX]

Originally posted by sharkinthepool
What I am getting at is the larger bore motors (416, 426, 440, 450, and the 473) are designed to breath easier! They are designed for lots of let off.

Unlike your factory engine. It is designed to run the way the factory saw fit. With compression and back-pressure at a balance.
Made to last and make the buyer feel this is a good company and that is what I should buy the next time.

Yes thats what I was getting at, sorry if i miss worded it. With motor work, the motor is now ready to accept the lesser back pressure without causing damage.

[Kilabanshee]

Yeah listen to steve-0 knows his sh*t. This is palmers buddy that you droped the ttr 225 off at my place, are you racing any of the last 2 PA series races because I talked to John and he said he might be racing dutchman on october 10th. Let me know because you dont live to far and maybe I can hitch a ride with one of you.

[Steve-o 400EX]

i'm lookin to race at least one more this year, possibly two. I am always up to givin rides as long as ther is enough room on the trailor so PM me when it is gettin close to race time;)