whats next?

[81 clark racing]

what do you guys think i should put into my 400ex next. i have the mods listed in my sig thanxs

[400exrider707]

rear shock

[brokenmike]

A lightened flywheel

[400exrider707]

Originally posted by brokenmike
A lightened flywheel


lightened flywheels have been known to decrease performance on these motors. Just a heads up.

[buster024]

+something arms??

[CarGuy7a]

hot cams stage 1. put one in mine and I love it.

[81 clark racing]

thanxs guys for all the responses. i think im going to do a stage 2 hot cam. what do you think of that? i just ride trails , however i dont want to lose anylow end power. will putting the stage 2 in make me lose low end? i have enough low end power with the mods i have listed im just looking for some more mid to top. thanxs

[CarGuy7a]

if you DO NOT have a big bore kit don't get the stage 2. for stock bore you need a stage 1 to keep most of your bottom to mid power range. the stage 2 is more mid and top b/c the big bore kit will give you most of your bottom power.

plus the stage 2 & 3 cams requires a rocker and valve spring upgrade.

stage 1 is a simple drop in cam.

[81 clark racing]

i thought a stage 2 was a drop in cam also? no offence but are you positive on what you just said is accurate CarGuy7a ? anyone else no if this is true or not cuz ive been told different thanxs

[j450rking]

i just got a stage 2 hotcam and all the papers say it is a drop in cam you can take the ex off the show room floor and put the stage 2 in it if you wanted

[maddmatt02]

my boss has a 400 with a stg 2 with stock valvetrain for a long time running now.

[CarGuy7a]

ahh i stand corrected. stage 1 2 and 3 hotcams use stock springs and rockers.

stage 1 cam is good for midrange and top power and is not recommend for big bore kits over 426CC.

stage 2 cam is good for top end best use for desert racing or motocross and is designed for big bore kits.

stage 3 cam is good for more top end and is designed for Hot Rods Big Bore Stroker kit and it also uses stock springs and rockers.

yeah i don't know where i got that from where you have to have aftermarket springs and rockers. it would be a good idea though if you're doing like a stroker or BB kit.

research from

www.rockymountainatvmc.com
www.hotcamsinc.com

[maddmatt02]

I personally dont think bore/stroke has anything to do with it, RPM's would have an effect because if youre revving real high then you better have good springs or you can get valve float, which is where the lobe actually loses contact with the follower and now the pistons coming up and the valve isnt folling the cams profile so its still open a bit and too much and BAM your piston hits the valve and youre F'd. and the stroker isnt built to rev like a BB anyways. also simply the fact that a cam has so much lift it can put too much stress on a stock spring, no matter what bore/stroke is.

[CarGuy7a]

Originally posted by maddmatt02
I personally dont think bore/stroke has anything to do with it, RPM's would have an effect because if youre revving real high then you better have good springs or you can get valve float, which is where the lobe actually loses contact with the follower and now the pistons coming up and the valve isnt folling the cams profile so its still open a bit and too much and BAM your piston hits the valve and youre F'd. and the stroker isnt built to rev like a BB anyways. also simply the fact that a cam has so much lift it can put too much stress on a stock spring, no matter what bore/stroke is.

yes that can happen with any kind of engine no matter what bore.
but with a stroker kit you run a greater risk of that happening because the piston is traveling a little further up and down. that's why i think it would be a wise decision to upgrade the rest of the top end. but really these cams don't have a whole lot more lift than a stock cam does. maybe 1 or 2 mm more. but the duration is different.