400ex bore kit...

[N400Ex]

-Alright first of all, before anyone suggests a try doin' a search, i already serched for this and no one has what i need to kno.

Anyway-

I have an 04' 400ex. I wanna bore it out, but i have no clue what size. 416? 426? 440? I do alotta trail riden and alot of track ridin too. ANd also, what is the most reliable size that wont blow up. And I wanna try and keep the cost down as much as possible, i dont wanna run race fuel, but some people say i need a bigger oil cooler and stuff. So i need some opinions on the best stuff to get. Basically i wanna smoke my friends by a mile, but not burn my wallet either. Let me kno....

-Nate


-04' 400ex
pro circuit t-4
holeshots all the way around
pro taper handlebars
modified airbox
k&N filter

well.. for starters, your really contridicting yourself.. you want reliablity and you dont want to hurt your wallet, yet you want to smoke your friends by a mile.. you gotta give someplace..

Your not going to notice any difference with the different bores just by themselves.. i mean youll notice a little bit, but it wont be like WOW.. if you go 406, thats 1mm over stock, and if you want reliablilty, then thats they way to go..

a 416 seems to be quite a favorate around here.. and will work quite nicely with a exhuast and a cam.. and is probably what would be suggested by most.. this is 2mm over stock, and most will say, thats as far as you want to take the stock sleeve.

Then there is the 426's and 440's.. now you can bore the stock sleeve to a 426, but most of the people will reccommend against it because of the weakining of the stock sleeve at that point, and is defaintly somthing i wouldnt do.. The 440, will have to have another sleeve put in, and with the right cam and exhuast, will prolly back the most punch for you..

The 416 will rev higher than the 440, as your not moving as big of a piston in the 416 as you are in the 440..

Now keep in mind, you can do all you want to the motor, but you will not go any faster unless you change the gearing.. now when i say any faster, that means on the top, max speed.. you will get there quite a bit faster on the other hand..

Total cost for this stuff?
a 440 with the machine work (this is if you do all the installation yourself) would come to about 500 give or take a few bux.. That price would be getting one of those kits off of ebay.. which many have and really like..

a 416 will cost you around 200-300 bux, and a little more with a cam, and alot more with a exhuast..

Its hard to say because you want it on a budget (dont we all) but.. this hobby is expensive..

Hope that helps
Jesse

[r-exrider0003]

My buddy has a 426 with a hotcam, a full sys big gun exhaust, and a k & n and his is pretty quick. Hasnt had any overheating or reliablity problems. I think he beat a raptor with a full yoshi, a 450r with a exhaust and filter, and itll smoke 400s with just exhausts pretty bad. He had a local shop do it for around $1000, but alot of the stuff in the motor needed replaced(rockers,cylinder,ect)

[CT440EX]

My 01 has the Ct racing 440 big bore and pipe. The guy i bought the quad from did all this to it so i dunno what it feels like without it but it keeps up with my buddies yfz just fine. i havnt had any problems with it either.