GS400 exhaust rot questions

[MrZig]

Turns out the PO removed the cross-pipe from the exhaust. Why, I don't know. What effect will this have?

Also when I had the exhaust's off, I could hear rattling in both of the mufflers and the ends are all rotted out. They both have huge signs of internal rot as well (patches welded on). Will this seriously effect performance?

In order to fix this, what can I do? Weld a new cross pipe on, and find a pair of harley mufflers for it? Any ole harley muffs?

Also what is the correct way to put the exhaust gaskets on? Mine only have these metal cylinder shaped things, listed as #1's on this diagram:

http://www.cmsnl.com/suzuki-gs400-x-1978-usa_model16011/partslist/91957.html

I don't have #2's.

Cheers.

[ikantbreave]

I'm facing the same problem with my 425. Mufflers are shot. If they're stock, you can't repack 'em and exchanging the mufflers is the only option. Probably have to fabricate a bracket too. Sounds like the baffles rusted loose. As for the exhaust gaskets (#2 on the fiche) they're way in there and very hard to tell with all the carbon and junk. I had to feel around with a seal puller to find them. Maybe check a junkyard for the cross piece too, or even Ebay. Exhaust from a 400, 425, and 450 should work for you. Good luck.

Brion

[doctorgonzo]

#1 is the flange, #2 is the gasket. You should put in new #2s, and I bet you have some in there. Get a pick and dig around where the pipe meets the head. You'll probably find them. Options for exhaust in general... cheapest route if the headers aren't rotted is save them and fabricate some mufflers attached to some fabricated mid pipes. Don't know if new aftermarkets are out there for that bike or not, but Mac would probably be the best shot.

[MrZig]

It's hard to just locate a muffler. I'll try phoning some scrap yards next week.

Does it really affect performance? I would think it would.

[Nessism]

http://cgi.ebay.com/ebaymotors/79-SUZUKI-GS425-GS-425-GS400-400-EXHAUST-CROSSOVER-PIPE_W0QQitemZ310182965976QQcmdZViewItemQQptZMotorcycles_Parts_Accessories?hash=item48385872d8

[Steve]

Turns out the PO removed the cross-pipe from the exhaust. Why, I don't know. What effect will this have? ...

The crossover might have been removed for any one of several reasons. Here is why I removed mine from "Freebie":




What effect will it have? It will slightly change the backpressure, as each cylinder will have to push all of its exhaust through a single muffler. The crossover would allow some of that to go through the other muffler, as well. It will also change the sound of the exhaust a bit, as you will now get the full sound out of each muffler, instead of splitting it between the two of them.

How did the PO "fix" the lack of crossover? Here is how I did mine:




I went to the auto parts store and got two lengths of 1 1/2" exhaust pipe that were flared on one end to fit over another pipe. I cut them to 7" to match the length of the crossover, then installed the pipes directly to the outer pipe/muffler assembly.

For what it's worth, what I did basically puts the system back to what Suzuki did before 1980.



Oh, before anyone thinks I am brave for taking pictures of exhaust parts on the carpet, I'll just let you know ... that carpet is in the garage.

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