400ex hp

[mtrombla08]

does anyone know how much hp a stock 400ex has? I have a 2005 with 440kit, k and n filter with lid off and hmf slip on and i only got 30 on the dyno. Does that seem right?

[J.Brown121]

as far as i know they have about 27 stock

[rcatvrider]

You have serious problems if you only get 30 on the dyno with a modded 440.

[Donjuan400ex]

yea 27HP is stock and agreed somethin isnt right if you got only 30HP out of it!! i would expect high 30s low 40s with modded 440

[mtrombla08]

so what do you think could be an issue here? i installed the piston myself and i know what im doing. is there something else im not thinking of or maybe forgot. the dyno shop did the jetting.

[odog]

from what i was told u wont get a high peak hp with just the kit i have a (460) i was told that you would just get high hp through the rpm range where the normal ex will be around 15 your probely at 25.the last thing i was told that you need to let a bigbore breathe a cam will help on power but a carb will defently wake that bike up 39mm fcr or 450r ive switch carbs and my bike is waayyyyyy faster.

[dirtman91386]

i agree with odog...cam and carb will wake that thing up!! having a full exhaust would help get a head pipe!

[mtrombla08]

oh ya is that what u think dirtman. **** u hahaha

A stock 400ex is more like 25-26. A modded 440 should be in the high 30's low 40's.

Originally posted by dirtman91386
i agree with odog...cam and carb will wake that thing up!! having a full exhaust would help get a head pipe!

Haha a noob with 5 post's even hates you.

But yeah, stupid question, but did you put the piston in the right way? I've seen it happen before.

What compression and do you have a cam? The high compression and cam would bump it up. Just a bore doesn't do much.

[dirtman91386]

dmc this bike gets walked on by k2thej....could just a head pipe make up the difference?

[mtrombla08]

thats my buddy but anyways yes the piston was installed correctly. it was an 11.5.1 weisco kit. no cam.

[hypersnyper6947]

Originally posted by mtrombla08
does anyone know how much hp a stock 400ex has? I have a 2005 with 440kit, k and n filter with lid off and hmf slip on and i only got 30 on the dyno. Does that seem right?

Doesn't seem that far off, what is your compression? I had a 11:1 440 with stage 2 cam, 450 carb and full exhaust, no lid and it only put down 33hp and 27tq on the dyno. My current set up lays down 37hp my mods are in my sig.

Think about it at 30hp that is a 11% gain which is pretty decent. Get a full pipe, some port work and a 450 carb and you will put down more. Also jetting is key.

[Muzzgit]

I would have thought a 440 would put out more than that, but as suggested above, wake it up with a cam and ported head.

My 406 with hotcam, ported head, K&N, Rocket slip-on came off the dyno last week with 35.4hp. I can't even remember which piston it's got, I just took it in to the workshop and said DO IT.

[TURBO-530R]

well what tires did they dyno with? and I wouls sugget cam and porting.

[F-16Guy]

The cam is the heart of the engine. Running the stock cam is severely restricting any gains you might have gotten with the big bore kit. Put in a good drop-in cam such as a HotCams Stage 2 or an XRs Only HRC Copy and see how much that wakes it up. Add a 450r carb to that, and it will really come to life.

[pbblaster2]

what do you guys think a
416 10:8:1 comp
hc stage 3
port and polish by ct
white bros full exhaust
yfz fcr carb

will put out?

[hypersnyper6947]

Originally posted by pbblaster2
what do you guys think a
416 10:8:1 comp
hc stage 3
port and polish by ct
white bros full exhaust
yfz fcr carb

will put out?

That is similar to my set up, you should be in the high 30's for sure.