How much power to expect from 426?

[FoxRacing81]

Hey guys this is the mod list...how much power you think I'll have? HP wise...or just by how hard it pulls...anyone? Gettin it tomorrow and can't wait.

Ross 11:1 compression 426cc
Cometic Head gasket and Honda HT sealent for base gasket
Redline Motorsports Race Port and Polish
Hotcam Stage 1
Wiesco HotRod H-D Crank and Rod assembly (I know it has nothing to do with power, just felt like typing it lol)
White Brothers R4 pipe
White Brothers Air filter
White Brothers Rev Box

I think that is all..

Thanks
-Justin

[Kilabanshee]

My quess would be around 38-42hp range. Take off that White Brothers ignition while you can. They really don't do anything as far as performance wise for the 400ex. Hopefully they are better then them procom ignitions "cheapy no name aftermarket cdi" I've heard alot of people go through problems with the low dollar ignitions including myself. I'de recommend a dynatek or a vortex ignition!

[FoxRacing81]

Well, the white brothers rev box increases it 1,000 rpm...so tis not that bad. If I can save up money, ill buy the sparks. Or..I believe I have heard of one from GT Thunder? Only thing I don't like about it is if my battery is kinda low, it backfires and won't start....but other then that...I haven't had any problems.

-Justin

PS, 38-42hp would be sweet!

[Kilabanshee]

I think it will be more in the upper 30's but You could see around 40hp if you added an fcr41mm carb along with an ignition. I almost guarantee you that the big gun cdi doesn't add 1,000 rpms. Your more likely to get 400-600 rpms out of it. I'm not saying things bad about their products but if you ever want a big increase and a gain of about 10-12mph with ajustable timing curves get the dynatek or vortex!

[QuadJunkies]

you could prol. get 4 more ponies if you could by yourself a 450R carb?? a well built 426 I was told by someone at Hetricks will get you around 40 HP when I got mine done.

[sloppyjoe]

yeah u def. need a carb. 39 or 41 fcr and u will have a nice runnin machine.

[yamablaster24]

The 440 im getting with stage 2 cam, ported and flowed 3 angle valve high compression piston with FCR39mm, custom metal air box and HMF exhaust dynoes at 49hp. Im buying Vortex ignition for it so the motor should stay with the 450's i race against. And right now im staying with them on 397 lol.

[troutman561]

yea def. get the white bros cdi off... the one i had messed with the timing on mine and also brought down the performance..... i could have done other things with $100 than waste it on that piece of crap.

[K_Fulk]

You should see about 35 depending on the dyno.

[426ex]

I just bought my first 2 quads. An 02 with 426 mod, stage 2 hot cam, wiseco 10:1, titanium springs & retainers and white brothers CDI and E2 slip-on for myself, and a brand new stock 400 ex for my wife. Mine literally smokes hers (understandably). I'm switching to a 14 tooth front sprocket today. You guys got me concerned about the CDI. I have heard a 250R CDI is an improvement over most of the aftermarket CDIs for this bike. Anyone know for sure? Are they a direct replacement, or will I have to do any mods?

[QuadJunkies]

Originally posted by 426ex
I just bought my first 2 quads. An 02 with 426 mod, stage 2 hot cam, wiseco 10:1, titanium springs & retainers and white brothers CDI and E2 slip-on for myself, and a brand new stock 400 ex for my wife. Mine literally smokes hers (understandably). I'm switching to a 14 tooth front sprocket today. You guys got me concerned about the CDI. I have heard a 250R CDI is an improvement over most of the aftermarket CDIs for this bike. Anyone know for sure? Are they a direct replacement, or will I have to do any mods? Dont know about that, but I have the GT Thunder CDI and have had it vfor over a year now and its worked great with no isses what so ever!! No issues starting either like the WB CDI seems to do for some ... ;)

[khen]

As far as CDI's, the White Brothers, Sparks and various others make your quad tough to start when it's cold out and the battery doesn't have a full charge. These are usually just XR250 CDI units relabled. The GT Thunder, TC and supposibly Big Gun and Magnum don't have these problems. With a built motor I would suggest getting a CDI.. it made a big difference on mine. When mine was just piped the CDI didn't make a difference.

As far as power out of your 426 I would say 38-39HP without a good aftermarket carb(or 450R carb) and 41-42 or so with one.

You should be very happy with those mods. :devil:

[FoxRacing81]

Well, turns out we had to run the cometic gaskets and not the sealer because when my mechanic took my cylinder off, the base was grooved..(he said it looked like who ever took the motor apart before him pryed at the gasket with like a screw driver and grooved it off....figures)..Will the power difference be that much noticeable between running the sealer or the cometic gasket? Will it still make them same HP numbers?

Thanks,
Justin

BTW, I remember reading in a RMATV catalog that the white brothers rev boxes and big gun rev boxes cause trouble starting. I don't know!

[vinson581]

do it once and do it right, get a dyna FS (dynatek) or a vortex ignition they are second to none, and you really do gain almost 8mph on top end, there was a review on here, and a stock 450r gained like 10-12 mph on top end with a dyna fs - thats insane! and something i am going to look at doing.

v581

[FoxRacing81]

It already has the White Brothers Rev Box. Maybe over the year sometime I'll upgrade.

[400exredrider]

everyone has been saying FCR39 or 41,,, but i have the 40mm and i love it! its a good medium between the two, dont take too much lowend and still has good top end. takes awhile to dial it in tho..... if you have to use gaskets, get the Cometic XR400 gaskets, they are thinner. helps a little, a little more compression.

[TCracin440ex]

dont run that stage 1 cam...i wouldnt even waste my money buyin a stage 1....go ahead and get the stage 2 cam....

[FoxRacing81]

Originally posted by TCracin440ex
dont run that stage 1 cam...i wouldnt even waste my money buyin a stage 1....go ahead and get the stage 2 cam....

It already had the stage 1 cam in it whenever I bought it.