I cannot get my Yoshimura to seal around the head. Am I supposed to remove the little donut gasket that is in there on each side?




Number one in this picture.

Thanks!

Each side should have one new #1, did you get the old gaskets out of the head?

I'll call up the dealer and get a new pair of them.

It also doesn't help that the inner bolts on both sides snapped in the head 

From experience I know those exhaust bolts are a real PITA.  The problem might be that you're not seating the headers right/tightening down evenly.  I did the install myself (pain), but it would probably be ten times easier if you had a friend hold the header in place while you install it.  Also have the TRS on the pipe when you bolt it down.

Quote from: Garrett on September 12, 2011, 07:14:59 PM
I'll call up the dealer and get a new pair of them.

It also doesn't help that the inner bolts on both sides snapped in the head 

Wait, so your saying each side only has one bolt holding it on?  That would be your problem.

Yes but my stock exhaust seals fine  I wouldn't be changing it except for the fact someone welded a YZ250F pipe onto my stock header like a dolt.

Get a set of easy-outs to remove and replace those broken studs, use new gaskets... it'll seal.

Quote from: kidsixteen on September 14, 2011, 01:53:11 PM
Get a set of easy-outs to remove and replace those broken studs

AARRRGGGGGUUUUUHHHHHH!!!!!.....NNNNNNOOOOOOOOOO!!!!

If it was that easy I would. I brought it to a local bike shop and they fubared one up so bad it's not even recognizable. Needless to say, I won't be going back there. I'll post some pics of what they did to it, maybe you guys can give me some help.

Quote from: Garrett on September 13, 2011, 08:15:37 PM
Yes but my stock exhaust seals fine  I wouldn't be changing it except for the fact someone welded a YZ250F pipe onto my stock header like a dolt.

So as I understand it...

Someone had previously welded another pipe to the head. Presumably you have had to grind or in some other way Cut this off, you are only trying to hold the new pipe on with two bolts and are using no gasket - and - you wonder why you cannot get a seal. Is that about right?

Michael

Let me get this right, reading comprehension escapes you.

Welded a muffler onto my HEADER. Little different than a head. The two inner bolts broke off and I tried installing an exhaust system but it failed. So I put my stock system with the  dirtbike muffler and it sealed fine. Why would my stock header seal but not a Yoshi?

Quote from: Garrett on September 14, 2011, 02:17:01 PM
Let me get this right, reading comprehension escapes you.

Welded a muffler onto my HEADER. Little different than a head. The two inner bolts broke off and I tried installing an exhaust system but it failed. So I put my stock system with the  dirtbike muffler and it sealed fine. Why would my stock header seal but not a Yoshi?

See, now we have all the info in one post and all is good with the universe again.

Michael

I'd assume it's because the mild steel of the stock header 'squishes' better than the stainless yosh.

If the bolt is that mangled, drill it out and use a nutsert. One way or another, using all four bolts and both gaskets is the answer to the problem.

stock header have a pipe(equalizer?) welded between the two runners.  This gives it extra support which allowed it to not leak much with only two bolts.  Most after market headers that I've seen for the gs does not have a pipe welded between the runners.  I know my Jardine doesn't have it.  Grab each header and try to flex them around while not bolted on bike.  I bet the stock will be very stiff and the aftermarket one will flex more