Well maybe he is bad at riding! he did get hit by a truck 2 times in less then a month and has over 20 grand into that yfz.

As far as my 400ex goes i have not done anything to it yet. other then buying new tires and rims. Still thinking about what i wanna do with it. A buddy of mine has 2 400's with 440's in both of them. He suggested just re jetting mine and something else bit i dont remember what it was. 8 or 9 of us are going out this weekend mostly 400 and 2 450s. so i will see what happens and go from there.

 

i had a 2002 400ex with fmf header and whitebros pipe and 426 bore kit and i ran a 160 dynojet and it ran great but i couldnt get close to my bros yfz450 'KOOPA' he has full exhaust system stage one cam and proflow kit. 450's are bad a?? !

 

i have a whitebros pipe but i dont know if i have a header pipe. it was on there when i bought the wheeler.

the guys with the 450 are also about 100lbs or more lighter then me haha

IMG]http://i241.photobucket.com/albums/ff88/lorenjr83/102_0001.jpg[/IMG]

 

 

it also seems like in 5th gear it revs way high and i have to back off to 1/4 throttle. maybe one of the previous owners swapped sprockets. what is factory on a 400?

 

He can get a 450r motor in the 400ex with out cutting or welding anything. I have a buddy, that found a company that makes the motor mounts, for 75 bucks, I put the 450 motor in my old 440ex. and as long as he does, like i did and go with the kick start. no worry with the wiring.

 

And man you just have a slip on. stock head pipe. but kick *** plastic. and the stock front sprockst is 15 i know for a fact. and the rear i belive is 32.

 

i heard of honda's 450 mx dirtbike motor put in 400ex frame. what do you think is better the 450 engine from the dirtbike or quad. i wound think the quad because its geared for the extra weight but i heard the dirtbike motors have more power for the same displacement because of fewer restrictions. is this ture.

 

the 450mx motor does have just all little bit mor touqe. but the only bad is that the 450mx only has one piston ring, when the 450r motor has 2. that is why alote of the 450mx honda rides go in to the top end. because of the ring wers out quicker.

 

dude the header is stock an fmf bowerbomb will give you up to 10% hp gain when i put mine on i could tell the diff.