WB Rev Box, Worth It?

[RideSportrax]

I own a 400EX:D :D :D
I love my quad to death, and am wondering about the White Bros. rev box. Will increasing the rev limit harm my engine? I would rather live with the stock setting than mess up my engine from overevving. Also is the Rev Box worth buying? Does it cause starting problems; how bad are they? Thanks for your help!

no, hard to start, and i had to roll mine down road sometimes to start it

I've had one almost since day one. The only noticable difference is the extra rpms you get. However, the extra rpms are out of the peak of the curve, so I see no benefit. Not worth the money.

[sabertooth]

Mine has ran fine and they are worth the money if you change your gearing for top speed. My sprockets are plus one tooth front and minus one tooth rear so I have less accelleration than stock gearing but I also have a longer powerband, the rev limiter is useful in my situation. Depends on what you have and how and where you ride.

[tprender]

The WB box will make it very hard to start in the cold weather during the winter. It will be a little harder or longer to start the rest of the time. If you run hare scrambles, a dead engine start, you will not get the hole. The quad will run a little better with the WB box at top end. It will not hurt anything if you put it on. There are some other ones(I think TC is one) that does not effect the starting any.
I will sell mine for $75 if you want it, I have gone back to the stock CDI box for HS racing because of the starts. Look me up this weekend at the Missouri HS race at Wesphilia and you can get it .

[400exBro]

If i were you i would wait till msd brings out their msd ignition system for the 400, i talked to the guy on the phone he said that it will be out in 2 weeks and it cost $481.
It chages a lot of things spark plug burning, timing, has a holeshot feature for racing so it doesn't bog off the line and you can program it your self of the pc with their program. I think it will be a lot better than a rev box. it will change the power band aswell pending on your set up.
I would wait and see how it works when it comes out.
Bro

[RED121572]

My 2cts from my own experience. My rev box was worthless until I got rid of that XR400 cam and replaced it with the WB cam.

Even with the exhaust and piston, it wasnt enough to push the bike the extra 1000 rpms until I got rid of the XR400 cam.

I read that FAT BOY RACING doesnt think the rev box is worth it. Actually, I think its his cam. That XR400 cam is overrated. It doesnt produce results at high rpms.

If you dont have a good cam, I would by pass the rev box and look into other modifications.

:D

[RED121572]

FAT BOY,

Not to insult you or your bike, but trust me on this one bud, say goodbye to that XR400 Cam and get something else. I promise youll be happy with the results.

[VegasEx'r]

I have been impressed with the performance gains that the xr cam gives over the ex cam, but I have been thinking of getting a different cam, because the xr cam is still just a "stock" cam. Why did you decide on the WB cam? How does the mid & top range w/ the WB cam compare to the mid & top with the xr?

[RED121572]

I didnt so much notice a "Huge" difference on bottom to mid, it was at top end where it really shines. It pulls so much stronger at high revs and allows me to actually use the extra RPM's from the rev box.

I had a cdi and all it did was let me stay in a gear longer, it didn't really improve anything, cause the motor doesn't make anymore horsepower in the higher rpms, I have switched back to the stock cdi, it was hard to start, your battery always needs to be fully charged with an aftermarket one. plus I felt I was just putting un needed wear on my motor so i switched back, I'll sell my cdi if anyone is interested, its a whitebrothers.