I want to jet and put a pipe on my 400EX. Could anyone help me out with which pipe to buy? I went to my dealer and they told me to go with the Yoshimura and I seen WB has come out with a new R4 series pipe. If anyone has an opinion on any pipe, please let me know!!

2000 400EX soon to be Mod.

 

It all depends if you are going to build your engine, like a cam piston or big bore. If your not planning any engine mods then I would suggest that you just get a slip on silencer like the WB or FMF, I think the yoshimira is the best though. Now if you plan on doing any engine mods at all then get the DMC full exhaust system, it is the best pipe out there for a built engine period. I hope my info helped out.

 

Hey LDJ, did you get your DMC pipe yet? Let me know what you think of it. I'm glad i got mine. I think the DMC is still one of the better pipes to get even without engine mods. My dealer has an FMF pipe and he rides with about 6 other guys who have 400ex's also. Most of the others have pipes too, including White Bros., Pro Circuit, and one guy has a DMC. He said that the DMC piped 400ex was always the fastest out of the group. All i know is mine was fast with just the pipe, and right now, with engine mods, it's really fast.

 

With a stock motor, a slip-on will give you good results. I first slipped on a Powercore IV2, drilled 6 1 inch holes in the airbox, went to a 152 main jet, and a 40 pilot jet. Huge improvement over stock! I then added the power-bomb header, I noticed a little improvement in that it revved a little quicker but no overall difference in speed. The performance I gained was not worth the $200 bucks in my opion. Maybe with a little more jetting changes I can squeeze a little more. Hope this helps.

 

I didn't get the pipe yet because, I just got the $350 to race port my head. At the end of the month I hope, or the first of December I will have my DMC. I will let you know when I get it.

 

I've got a WB R4 slip-on on my 400 and it sounds great and looks pretty good to. With the 440 that's being installed as we speak, I'm going to get the pro-meg head pipe for better flow. A buddy of mine has a DMC on his 440 and it is alot faster than when he had a Big Gun.

To be honest, when I installed my R4, K&N and jets I really didn't notice much gain. WB sent a dyno sheet with the pipe claiming almost a 2 hp. gain. Again, I couldn't notice the gain.

If I had to do it all over I would get a full DMC pipe ($479).

 

Thanks for the help so far!! I went to look at a Yoshimura pipe and it looked pretty sweet. Does anyone know what this pipe sounds like, and if it makes a difference?

 

With correct jetting the Yoshi pipe will greatly improve performance. The pipe is very loud, but the sound is a very deep throaty sound. The fit and finish is the best!!

If you decide to get the Yoshi get the full system. The header pipe is much larger then stock. Do not spend the extra money on the Titanium series. It saves a few pounds but their is no gain in performance.

 

Couldn't have said itbetter than Santa himself. My bike cranks now compared to stock.

 

Thanks for the info. Santa, you talked me into goin with the full Yoshimura system. What else should I do to my machine to make this pipe work the best. Jet and put a K&N filter on it or is there something else, I don't know awhole lot about this stuff?