Which Rev Limiter

[ride_red_5400ex]

I donno which rev limiter to get a big gun or a white bros. give me any pros or cons

[KY Woods Rider]

I don't really know anything about the Big Gun rev limiter because I've never rode a quad that had one on it. As for the White Brothers that I have, I think it was worth it. It isn't a total night and day difference, but I've spent $125 in worse ways. Basically, since the WB has a more aggressive advance curve than stock, the motor tends to rev quicker and more freely through certain areas. I'm guessing at RPMs just going by "feel" but here's my opinion... idle-2500 RPM it feels like the stocker, from 2500-7500 the motor picks up the RPM faster and revs more freely, from 7500-rev limit it feels similar to stock or maybe just slightly better, but you get more RPM before the rev limiter kicks in. The higher rev limit helps a lot in those times when you don't have time for another shift and just have to scream it, because with a good aftermarket exhaust you should still be pulling pretty hard when you get to the stock rev limiter.

The only bad points to the WB rev limiter is that some people complain of hard starting. Personally, I haven't had any problems with mine in the entire year and a half since I bought it, it starts just like it always did. The only other bad point is that it might actually slow you down in really slick conditions if you're not careful. Since the RPM comes up quicker and easier, you have to be more mindful of the throttle when coming out of slick corners.

[86atc250r]

It's likely that they're the same thing. There's a lot of people out there re-packaging XR250R CDI boxes for 400EX's.

[cals400ex]

how much on average do the xr250 cdi boxes run?

[86atc250r]

Can't remember - look up the part number on partsfiche.com, then plug it into servicehonda.com for a good price.

[Paul400ex2002]

the only way people are having a hard time starting with the rev boxs is if there battery isn't at FULL charge. It even says that you will have problems starting it unless you have a full charge. those wolf cdi boxs and there's a couple other are cool, they are more expensive but you get 2 or more different spark curves.

[86atc250r]

In reality, anything that causes the engine to turn over even slightly slower than "normal" will cause a no start condition with an XR250 based box.

This means a low battery, cold weather, high compression, weak starter, or any combination of the above.

The XR250 CDI has an "Anti kickback" circuit built in. This protects the rider from a painful "kickback" if he doesn't get the engine kicked over fast enough and the mixture pre-ignites (you old-school thumper riders will know exactly what I'm talking about) -- unfortunately, this minimum RPM is right at where the EX normally cranks - hence the starting problem if anything at all causes the engine to crank slowly.

There are other CDI boxes available that don't suffer from this problem - I'm not sure where they're sourced, but they're out there. I have one myself (as well as an XR250 based box).

With some of these though, you have to be careful, because they'll advance the timing enough in the bottom end to cause some healthy pre-ignition which is very hard on the engine.

[F-16Guy]

I have a WB box for sale if you're interested, $75 shipped. PM me.

[CHAUNCY]

I have a WB rev limiter and love it. It works great:)

[JD400exrider]

I have a rev box that increases the rpm to an extra 1000 rpm. Bought it from my local honda dealer. (Carmichael Honda Motor Sports.) Used it for about 3 rides. No problem starting at all. Sell it for 75.00 shipped. PM me if your interested.