grinding welds in exaust

[BARRY]

ive heard this will give you top end,but when i went to do it the only welds i can see are on the outside and the ones on the inside are next to impossible to reach.grinding the outside headpipe would make no sense.can some oneexplain this?:blah :confused: :macho :rolleyes: :D :devil :huh :grr

[Woodsrider]

The welds are in the inside of the pipe. about one inch inside of the opening. I used a dremel tool on mine and a air grinder on all my freinds XR400's. We all agreed the gains were in the bottom end not on the top. and the difference was noticable on all 5 machines.

I have no idea what welds you are talking about on the outside of the pipe.

[BARRY]

ijust assumed that you would be able to see the welds on the out side.thanks i will pull exaust and grind them tomorrow:devil :devil :devil

[brian400ex]

Does anybody have a pic of the welds in the pipe? Are they all the same on every 400ex?

[TheChknhwk]

The welds are about 3/4" inside the flange & are about 1/16" tall. I did not notice any improvement from it, but it has to better the flow a tad. Also I had to drop the oil resevoir to get the head pipe out. Someone told me to just keep wiggling it & it would come out, but I did not see any civilized way to do it.

Hawk