can u do a 400ex cam mod

[jeryk]

i need just a lil more power on my 400ex to out run a modded yfz i can smoke a stock but one my friends done a cam mod to there yfz and is there any cam mods on a 400ex that i can do or any other little mods that anit to hard and can be done at home

[ae13291]

we cant do a cam mod lol its a single cam motor. but u can do the sparks advance mod which is basically the same thing

[2muchquad]

its gonna take more than a cam "mod" to run with a 450,even a fully built 440ex would have trouble with a stock one.Get a aftermarket cam along with a high comp piston and exhaust and go from there,it still wont be a 450 eatr though...sorry

[jeryk]

well it anit all stock i got a 460 in it step 3 cam. hmf pipe and the 40mm lectron carb on it from a yfz and a few more little things
but i havent raced them with the carb on it yet it realy made a differance on it but its been to slick to count the race

how do u you the sparks advance.

[ae13291]

you advance the timing b6 6 degrees by putting a new flywheel key. search sparks timing advance

Originally posted by jeryk
well it anit all stock i got a 460 in it step 3 cam. hmf pipe and the 40mm lectron carb on it from a yfz and a few more little things
but i havent raced them with the carb on it yet it realy made a differance on it but its been to slick to count the race

how do u you the sparks advance.

Changing or doing any thing to a cam isn't going to help much.

Valves and port it and if you have a stock header change it.

Another thing thats odd is going from a Oring chain to a non oring chain adds 1hp.

For like $400 I think you can get a sidewinder sprocket kit which will have you like another 4hp faster cause their so light.

[jeryk]

i already have ported and polished the head and the header is a new hmf

does the spark timing advance give more throttle response

[ae13291]

it will give better throttle response and it will give more power throughout the entire power band. search it and u will see

jeryk, what compression are you running?

Being your running a 460 and stage 3 cam, honestly I wouldn't do the sparks key if you have over 10.1:1 compression. They say not to use it on big bore or high compression over 11.1:1, but if your running that and the stroker/bore your asking for trouble.

If you don't mind running race gas a 12.1:a piston will add more power.

[jeryk]

well i think that i am running a 11.1 compression in it now i anit fur sure ill get back with ya tomrrow ill have to ask my machanic first but thats what i think is on there

[justin1022]

just list out all your mods. i am curious how is it cooled alot of people on this forum have added a fan including me to my 440. list out your mods and people can tell you what to add to make it beat a 450. and also it will save them trouble on saying stuff you already have.

[jeryk]

well my 400ex has
460 big bore
weisco piston i think its 11.1 compression
step three hot cam
ported and polished head
new crank
new timing chain
motion pro clutches
hmf pipe and header
40mm lectron yfz carb
workin on puttin a 16 36 sprockets and chain on it right now
lowered
that it im purty sure

[2muchquad]

a yfz has a fcr carb unless they changed it to a lectron,the fcr carb is superior imo.

[jeryk]

yea i anit for sure but this carb is a few years old i never got around to puttin it on the yfz becuase i ended up gettin a better one so i tryed it on the 400ex i havent got to test it out its all there has been is snow on the ground i dont want to take a risk of blowing my motor over it so im just gonna wait until it melts first i cant wait i gave it tons of power on it

Originally posted by jeryk
yea i anit for sure but this carb is a few years old i never got around to puttin it on the yfz becuase i ended up gettin a better one so i tryed it on the 400ex i havent got to test it out its all there has been is snow on the ground i dont want to take a risk of blowing my motor over it so im just gonna wait until it melts first i cant wait i gave it tons of power on it

Stock valves? Or +1/+2

[jeryk]

+1

[justin1022]

dude your quad should woop a stock 450 easy. i have a 440 wit hot cam stage 2 rev box hmf pipe a fan and i forget wat else and it beats a stock yfz.

[jeryk]

i know i can smoke a stock yfz and my friends got a lil stuff done to it and i can keep up with it i just need a lil more power to get a head it says

[justin1022]

k well if i was you i would but some 18's on the rear should help with acelleration. i would just mess around with sprokets because your quad is modded right out to were its pretty much a ticking time bomb. mine also i wont do nothing else to mine cuz im scared of it blowing

[jeryk]

how did u get the fan cooled on ur 400ex

[2muchquad]

i have a fan on mine from i believe a 500ninja street bike.its mounted just in front of the steering stem.Keeping the temps down is the most important thing you can do...period.Well making sure the engine has oil in it but besides that:D

[jeryk]

my uncle put a tracker fan on his grizzly cause there about the same motor except the tracker goes faster any ideas about that working and how did u wire it up with out the relay for the fan

[2muchquad]

i have mine ran off a switch,one side of switch to the fan and the other side to the positive terminal of battery.Take the other side of the fan and ground it to the frame.by keeping the head area cooler,it should help keep the studs from pulling out.im also gonna add a bigger oil cooler as well,heat is the enemy..danger danger danger:D

[jeryk]

yea same with mine my bolts pulled out the head about a month ago and thanx i thought that it might work does it drain ur battery much while ur atv is running

[tyman2395]

my brother has a ninja 500 i should take his oil cooler off lol he is away at college lol