Exhausted

[Guest]

Anyone know if a 1979 gs850 exhaust port is the same dimensions as a 1981 gs850 ?
I am trying to connect a pair of Mac brand 4 into 2 off a 1981 gs850 , but the header end of pipe seems too long and not wide enough . The dimensions of top end of pipe are 43mm OD X 26mm length . The port on the 1979 seems to be 47mm wide and 17mm deep . Am I missing something ?

[Steve]

Exhaust ports on all 850s are identical.

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[mcgladdiator]

So do you think with the gaskets it will tighten up ?

[dorkburger]

Not sure what you mean by too long. Does the tube not slip in the head far enough to catch the bolts?
Check the head to see if the old crush gaskets are stuck in there. They have a tendency to hide themselves, especially if the old exhaust leaked and covered them in carbon.

[mcgladdiator]

Here is a pic of the port that might help with your diagnosis . Thanks !ex1.jpg

[mcgladdiator]

How it looks , when connected .ex2.jpg Notice the gap ?

[mcgladdiator]

The tube slips in to head ok , but loose and wont go in all the way to tightening flange . Bolts connect and tighten down about half way then the big gap . Thanks .

[dorkburger]

If your referring to the space between the header flange and the head, that's normal on an aftermarket header. It looks fine to me. Just be careful tightening the bolts. Personally, I use anti sieze on the bolts to ease future removal.

[mcgladdiator]

Thanks Dorkburger , Would you say by my pics that the gaskets crushed and stuck in the head port ?

[dorkburger]

I can't tell for sure, as my bike's ports are a bit different. The gaskets are some sort of soft metal and crush by design when the header it tightened down, so there is a chance they are in there if nothing fell out when removing the old exhaust.

[hannibal]

It looks like there's at least one gasket stuck in there.

[mcgladdiator]

Thanks boys for the advice ! What's the best approach to yank them out ?

[steve murdoch]

A thin blade screwdriver should pry them out.
Princess Auto/Harbour Freight sell a pack of dental picks for about $5.00.
I have used them many times for many things, just like this.

[mcgladdiator]

Thanks to y'all for the help ! This truly is a great website and forum !

[Buffalo Bill]

Here is a pic of the port that might help with your diagnosis . Thanks ![ATTACH=CONFIG]50409[/ATTACH]

It looks like a gasket is in there. They are made of lead, and easy to scratch with a nail. Much easier to scratch than aluminum.
Give that a try. You can pry them out with a screw driver, however why not just use them again?