Topic: Short mufflers

[DV Red Herring]

My exhaust has a few rust pinholes in the muffler area. The pipes seem to be fine. I'd like to save this exhaust by welding on new mufflers. What sounds good without being obnoxious?

[Yamahawk]

Where would you cut the old cans off at? where the pipes meet the muffler, or further back on the can? You will have to weld something on there, I personally, would find some standard O.D. thin wall stainless pipe from your local muffler shop, and weld it onto where you muffler now is welded, after the two pipes meet,  and then CLAMP on a replacement muffler. That way, you could change your cans if you didn't like them. I would like to see some Dunstall-type cans with a slight upsweep like on a Norton Commando, reverse megaphone tapered ends. They should also sound pretty sweet on your CB750. Sorting out the length of the stainless pipe to get the proper mounting for your cans would be a consideration. If the place you weld to is larger in diameter than the pipe, your muffler shop could expand the pipe, within reason, to match the O.D. before you weld it. 1 3/4" stainless pipe would make a good extension for that. You can also have them neck it down to fit your I.D. of the mufflers you pick. The muffler shop can even bend the pipe to any slight bend you might need.
Charlie

[DV Red Herring]

Thanks Yamahawk!!! I would probably have to cut several inches back from the collector as the head pipes enter the cans side by side. Have you seen any other short style exhausts anywhere? I may just retire this set to the garage wall, and find an entirely new system.

[Yamahawk]

I haven't been looking, are you still into the 4-2 side pipes? If so, MAC has a set new, but your bike would look nice with the Delkevic 4-1 stainless header they sell for around $230, and then what ever shorty can you want. If the cans on your present system are rusted through, go ahead and cut them off, and then measure the O.D. of the stub. Make sure you chop them where it is round, instead of oval from the entry of the two pipes, unless you want to recreate the header collector. Then, you could sort out the divergence into the 1 3/4" tubing from the local muffler shop. I like the look of the upswept type European mufflers, and think they would look pretty good on the CB750. Anyway, keep us updated on what you decide to do!
Charlie

[Yamahawk]

The Hindle is a nice exhaust! But by the time he spends all the money to re-chrome or ceramic coat the headers and pipes he welds on, he might as well buy a new MAC or Delkevic system. I figured that the OP wants to do this economically, so that's the options I gave. And, the original chrome won't be damaged except where you weld the stainless or carbon pipe to it. There will be a heat zone there. You can polish stainless to look very nice, and then clamp a muffler to it. Or if you wrap the header down to the stainless tube, it will hide the weld zone. I have some 308 stainless wire in my MIG welder, and run Argon purge gas and it welds dissimilar metal just fine. 309 has a little more nickel in it, and is normally what the piping industry uses for a 'proper' dissimilar metal weld. In the real world, I have used ER70S or 7018 stick rod to weld 316  or 304 stainless pipe to carbon steel pipe. Never a strength problem. There is always a heat zone there between dissimilar metals, and whether you weld carbon to the header, or stainless, you will have an area that will rust, unless you either rechrome, ceramic coat, or paint it with high temp exhaust paint. Those are all options. But whatever you decide to do, it will be something that You made!
Charlie

[Don R]

 Those pipes sound awesome don't they? I had a set on my cb500. Action 4's if I remember right.
   Look for stainless truck exhaust tips that could fit over your mufflers, then get a set of 3 or 3 1/2" insert mufflers for car side pipes like a cobra or vette. Jegs and Summit used to sell them. Patriot brand I think. A stainless band clamp could hold them on.

[DV Red Herring]

Don R, I'm not entirely sure of the manufacturer of this exhaust. I do know that I haven't seen another set like it, aND I do lIke the sound. That's kind of why I want to repair vs replace. All really great ideas. Thanks guys.