400ex header ?

[honda400ex2003]

Hey does anyone elses 400ex header make noise with an aftermarket Slipon? It doesn't do it with the stock exhaust on it, only with the t-4 on it. It does it once you get to the middle of the revs and up. Just wondering if anyone else has this noise. Thanks alot Steve

[smith_400ex_213]

were is the noise coming from

[cals400ex]

does it sounds like a mesh screen rattling? if so, that is just how the aftermarket pipes are. if it is where you connect the silencer to the header, try to put an exhaust gasket there like one that comes from the factory.

[honda400ex2003]

It is not the screen. It is coming from the headpipe. I checked that when
I first got it. It doesn't make that where the 2 come together. The connection of the 2 pipes and the header is tight but it makes this annoying vibrating sound. Maybe it is just me but it does bother me alittle.

[honda400ex2003]

The sound is coming from by the pipe right when it comes out of the motor and when it is in the bend in the piep sorry about that. Maybe it is just the air that makes the pipe do it. It may just want to get more out than the pipe will let it. Does that sound like an answer or no? I'm not sure. Thanks alot steve

[plkmonster2]

I've got the same problem. It sounds like there is a plate rattling against the frame or something. I don't know what it is though.

[honda400ex2003]

Yeah that's what is sounds like, a plate rattling, but does anyone have an answer. At lease I know I am not the only one with this noise. Thanks alot steve

[plkmonster2]

I think it is the pipe. It is connected to the frame, and vibrates it, so it sounds like it's all over.

[cals400ex]

i have no idea. i have never heard of that before. are the crush gaskets good in the head? is the header bolted down all the way? maybe you could go over the whole bike and look for loose bolts. that seems to help my quad out sometimes.

[plkmonster2]

I meant to say header, not frame. Don't know what I was thinking, doh! I hope that helps to explain it. The hmf uses no gasket either.

[honda400ex2003]

I've checked just about all of the bolts and it stilldoes this. I have never had the header off, would the gasket go bad if it hasn't been off before. I also doesn't do this with the stock silencer on it just with the t-4. i just am not sure. Thanks for the help anyway. Steve

[cals400ex]

i really don't know. i guess you should go buy a polaris.

[honda400ex2003]

Hey Cals400ex did you know that a sportsman 500 doesn't float with 589's on it? I did. I know from experience. I have put one through the lake in front of my house. Polaris SUCKS!!! Thanks for the advice anyway. Steve

[Honda Ride Red]

i had a rattle like that but it was with my stock exhaust and it ended up being the heat shield on the side by my leg. one of the bolts came loose.

[honda400ex2003]

Hey Thanks for the info on the exhaust header. Thanks alot I will recheck everything in the front of my machine. Steve

[cals400ex]

Originally posted by honda400ex2003
Hey Cals400ex did you know that a sportsman 500 doesn't float with 589's on it? I did. I know from experience. I have put one through the lake in front of my house. Polaris SUCKS!!! Thanks for the advice anyway. Steve


i realize the polaris bikes aren't the best. i was giving you a hard time. i know how to fire up honda fans!! :p

[honda400ex2003]

Same for me with yamaha. All my friends ride yamapuches. One has a 350 warrior, another has a 350 raptor, and another as a blaster. It is really fun to mess with them. I am faster than all of them it that makes it all the more fun. My parents used to have polaris's, but now they have hondas. The only way to fly. Talk to you later Steve

[cals400ex]

Originally posted by honda400ex2003
Same for me with yamaha. All my friends ride yamapuches. One has a 350 warrior, another has a 350 raptor, and another as a blaster. It is really fun to mess with them. I am faster than all of them it that makes it all the more fun. My parents used to have polaris's, but now they have hondas. The only way to fly. Talk to you later Steve


just make sure none of them get a 660 or a yfz. yamaha knows how to build fast bikes, i just wish they had honda's name stamped on the side for reliability reasons.

[400EXdude]

hey i hear about people grinding the welds out of the header what does this mean....where are the welds...and does it increase power by much..thanks

[cals400ex]

the welds are right inside the two pipes on the header where they enter the head. you need to remove the header to see these of course. it isn't a huge gain.