REV kit for a 400EX

[EXfireguy]

OK, I know this has been asked. BUT, I am in the market for a rev box. Heard WB is trash. PLEASE let me know what is the hot setup out there. I have a race on the 24th and want to have it in and tested prior to race time.
Thanx,
Chip

[400MXer]

Fischer Cycle sells a rev box that doesn't make your bike start hard in cold weather...AND it revs way high...but it's still safe.

tell them that adam purser sent you!

Their number is

(440)997-4166

I jusy installed a sparks racing rev kit on my 400ex,Tuesday. I could tell no difference in power band. The only difference I could tell was it bypassed the banging at high rpm's. Understand this banging is way past the power curve so it had no effect on speed or power. Wednesday I got ready to ride and it wouldn't start, I tried ether, to no avail. I finally put the stock rev box back on and it fired up. Friday I mailed the rev box back to Curtis Sparks.. I believe I will spend my next money on a different cam, besides Honda had the rpm limiter set at particular rpm for a reason.

[RAPTORAZ]

I have not had any problems with my White Bros. box.

Just wondering?
Since the torque curve and the horsepower drops off before the stock rev limiter, why is revving it even higher helping. The torque and horsepower are on their way down at such high RPM's.




REDNECK400EX1
Basically stock 400ex- CT racing pipe, K & N and outer wear...

[stevengates45]

i say just modify ur stock rev limiter

[redrider05]

I have no trouble starting my 400 with the WB rev box.
Have you tried starting it differently .
:)

The wb cdi will eventually give problems in starting,,mine gave me problems in the middle of the summer it wasn't cold at all,,and I start my quad the same everytime,,if ya ask me wb is rippin people off,,I now have my stock CDI back on and it fires everytime.

have the wb rev limiter no problems starting it either just pump the throttle about 3 times before i fire it and it starts right up no problemo

[mopar 400]

I definitly have to agree with Jerry Cain, I think Honda put the rev limiter where it is set at for a reason. If it isn't goin to be a huge noticible difference I would suggest spending the 100 dollars on something useful.

[ChadEXer]

I dont think there needed:D

[ATV_MAN]

My friend has a rev kit on his 400 ex and he can adjust his rev by just tuning it up or down.

Anyone wondering about this item please do not message me about it because i have no clue where he got it and it was already on his quad when he got it and he doesnt know where it was from.

[stevengates45]

ive found that theyre really needed for my type of racin because i have to wind my gears out really high.

[DiceMan400]

There is no need to change or mod your stock rev box......

[ChadEXer]

A lot of people say its need and a lot of people say its not need:confused: Tom is putting one of his limiters on my bike!!! thats kind of scary though. I definatley dont want to blow up $3000 worth of motor work:(

I had an unlimited rev box from TMM on mine and I blew her up in the middle of a race in the heat of battle I let her fly in 3rd and snap!!!!! Must say that I had no prob starting it whenever, matter of a fact it started easier than the stocker. I think they modify a 350 CDI box, it was a bit bigger than the stock one. I immediately put the stocker back on following an expensive rebuild. Look at Doug Eichners 400, all the mods and they still use the stock box.......Heard nothing but bad from the WB box.

[Texan32]

To all you guys running stock cdi's...VERY smart. If you look at the power curve on the 400, the HP and Torque do start falling the higher RPM you get. So, winding out your motor is really not doing you all that good. I've also seen dyno results with the WB box. It looks NO BETTER than stock. Actually, it looked worse.

To me, there is only 1 advantage to unlimited revs. You can go just a little bit faster on top end. But, i don't see how 2-3 mph at wide open in 5th is worth chancing a $2000 plus motor.

Your better off sticking with the stocker and not gernading an engine. But, its your ride and your money. Ya'll do what you want. This is just my opinion.

[James70214]

I have been thinking of getting one. The only reason I want one is at th track I race there is a 30ft little double right after a corner and I case it in 3rd pinned by only a couple feet. There is no room to up shift.So I think the extra 1000rpms will let me clear the jump exactly. What do you guys think? Is any rev box better than any other( sparks, fischer, white bros)

[trx400ex]

james, i dont think the rev box will help you clear that jump, it might, but it would be a much better idea to just do a cheap mod like a slip on or 416 and runner a little taller gearing

[VegasEx'r]

I only use the WB box at the dunes. It doesn't give you any power, but I like it because a couple of times I have hit the stock rev limiter right at the base of a hill, and it killed any chance I had of making it to the top. I still shift at the same points, & make it a point not to overrev, but if I could figure out how to wire in a shift light, I wouldn't need it. Going over the stock RPM's makes less power, but hitting the rev box takes away even more power (that statement comes from the tried & true seat-of-the-pants dyno). I have had a couple of problems starting it when cold, but switching the boxes fixed that. IMHO, it's not worth the $100 or whatever they cost now.