To grind or not to grind

[jenkinm]

I have been told that I need to grind the manifold side of my 400ex header pipes. This is supposedly to help the airflow after installing a T-4 slip-on.

Is this needed? I understand the theory behind this but does the 400ex header have such a restriction at the manifold to need grinding down? I have not taken mine off to look yet.

[stupid driver]

there are 2 welds on the insides of the headers. You wont feel a huge difference, but with a filter and a cupple other mods, it will deffinately be noticable.

[jenkinm]

Mmmm....

I see. In this case then I will not do it yet. The breathing is still standard. Will keep it in mind though.

Cheers

[skemp]

I personally do not think it is worth much, and others would agree, but some think it makes a world of difference. Do what you wish, but to me the minimal gain does not warrant the time and effort put into removing the pipe and grinding the welds.

[Woodsrider]

Each manifold is different. I have ground the welds in four manifolds, on both EX's and XR's, and found there to be a significant difference in the size of the bead. This being said, I guess its up to the individual as to wether this mod warrants the time and hassle. On my quad I suppose if I had it all to do over again, I probably would. Maybe fifty/fifty on the four I have done.

Ahh fug it just go buy a new exhaust system:D J/P

[foxhonda_400ex]

if you have a die grinder it doesn't hardly take anytime to do, but i've done it and it does help a small bit over the stock pipe, if you have jetted carb, and air filter

[JOEX]

Originally posted by soggyrider
.....Ahh fug it just go buy a new exhaust system:D J/P
Some of us aren't as lucky as you!:devil:

Joe

[Woodsrider]

Originally posted by JOEX
Some of us aren't as lucky as you!:devil:

Joe

:D Now if I can just get it to stop dumping fuel out of the bowl:grr:

[JOEX]

Originally posted by soggyrider
:D Now if I can just get it to stop dumping fuel out of the bowl:grr:
Time to douche the carb? My friends Lakota had that problem, he took it to the shop after we both messed with it with no fix. He took it to the shop, under warranty, they fixed it. I wish I knew what they do for that other than clean it out. His 400 did the same thing after it was standing on the grab bar for a few hours. After riding it awhile a bit it stopped.

I'm sure the just needs to be taken apart and cleaned real well.

Joe

[Woodsrider]

could be, but Im not quite sure. It seems as though the float is out of adjustment. The bowl drains even on a bumpy trailer ride if I dont shut the fuel selector off and run it dry. But when I checked it the other day it seems to be set properly at about 18.5mm. I dunno, but if I dont get it figured out soon Im taking it to the shop and let them fix it. There comes a point where it worth it to pay some one else to fix it. Im too busy right now to work on my own stuff:confused:

[JOEX]

Yeah, I know how that goes. I spent the last two days rebuilding my computer. The first time for me. Damn near f'ed everything up:rolleyes: It's still not completely done but it works!

Joe

[skemp]

Originally posted by soggyrider
could be, but Im not quite sure. It seems as though the float is out of adjustment. The bowl drains even on a bumpy trailer ride if I dont shut the fuel selector off and run it dry. But when I checked it the other day it seems to be set properly at about 18.5mm. I dunno, but if I dont get it figured out soon Im taking it to the shop and let them fix it. There comes a point where it worth it to pay some one else to fix it. Im too busy right now to work on my own stuff:confused:
Sounds like a bad needle/seat or something stuck in there. Check it out if you haven't already. :)

[cals400ex]

my friend had a problem with his bike wanting to die when going up steep hills. also, gas would come out of the carb when doing wheelies. i know some may come out but his was a steady thin stream. he took it to the dealer and they said that they changed the floats on the 400ex's in 2001 or 2002, i cant remember. he has not had the problem since after they put a newer style float in.