im going to buy a pipe for my 400ex and i was told that the header pipe is pritty good so i was woundering if i should just buy a slip on or go headers and the pipe?


o ya and how hard is jetting on the 400ex 2003

 

My friend would also like to this this. He wants to get either the sparks, LRD or trinity. Which one do you guys think would be his best bet. Money kinda is an issue to a certian point. Any help he would appreciate

 

curtis sparks is what i would get. jetting is easy. all you have to do is remove the 17mm bolt on the bottom of the car. before you do this, make sure you turn your fuel off. some will still drip out of the carb but that is ok. the mainjet will be right inside that hole. i think the mainjet will be 5.5 or 6mm. just unskrew it and skrew the new one in. put the 17mm bolt back on and your done.

 

do you have to take the carb out or can u just leave it in there.?

 

You do not need to remove the carb to change jets.

Most engine builders have agreed that the headpipe on the 400EX is one of the best breathing headpipes out there for a stock machine. You won't see much gain, if any, adding a aftermarket header.


There is a trick, though. If you take the headpipe off, and look down into the pipes, you will see a thick weld bead. Grind it down with a Dremel tool. You now have a much better breathing headpipe, and saved yourself $2-$300 you can spend elsewhere.

 

kool thanks.


i decided to go with the white brothers e-series pipe for 230.

dirt wheels said that was the pipe to go with for the 400ex.

 

I just got a white brothers e-series pro-mag full system head pipes and everthing For my 400ex and it' ome. One of my friends just bought the slip on for his 400ex and ming is way better. Since you are getting a pipe anyways its allso good to get a k&n power kit it helps alot to OK.