I am trying to fit a new muffler to my header. As everyone is aware the OD of header is slightly less than 1.75". I know about using 1.75 ID" and placing a small sleeve to make up difference. Problem is the new mufflers ID is 1.75". So I went to local muffler shop and had them make a bend in some off the shelf "Pep Dudes" 1.75" OD pipe. Problem was the expansion die they needed was the only one they didn't have. I took it and the header to the local Meineke, the guy asked if it was for a Harley, I said no, he said is it for a "Kawisucki", I said no a Suzuki and his comment was "same difference". Any way he put it on machine and just hit the peddle until it burst at seem. He than told me it was cheap pipe and if I had them make it from their superior pipe it could be done. They want a big piece of change to make one. He did lay a bead of weld on the split. but it is a mess inside and needs ground out and is still split at area of overlap i.e. weld doesn't extend to the end.

I am going to try the whole process again with the slightly heavier wall Napa tube, but if it doesn't work? I'm sure there are those who have done this sort of thing before, any advise.

One problem is that it is a short adaptor and the bend needs done in a longer piece of tube, then cut to size and the expansion done after it's cut.

So cut to chase, if I have thicker wall 1.75 OD tube from Napa, have tried to expand it myself by hand with a manual expander but cant get it large enough. My idea is to cut a series of fine lines in the end, the length that it over covers the header and try to expand it than.

Or would it work to take 1.75 ID, do basically the cuts in other end but instead try to compress it down to fit into the muffler. Obviously I don't want the thing leaking at the joints.

Anyway, maybe I am going about it all wrong, any advice would be appreciated.

Thanks, Dave. My understanding is you have to cut the header to make that fit. I was under the impression the Ryca cost around $70.00, so the link is helpful to know.

On another note the new muffler requires a bracket to attach to the mount  on frame, I had mocked up an adapter out of flex pipe and already fabricated bracket out of stainless. The ryca it's shorter than the one I am trying to make. Desire is to have the muffler to extend beyond rear hub to try and keep it clean (read a lot about issues with that and shorter pipes). So anyway, I would also need to do a new bracket.

Problem I ran into was the mock-up had a Supertrap on it when I got it and apparently the previous owner had ground down the header to get it to fit. When I was doing all the layout and prefab, 1.75' OD pipe fit on the header of that bike. I know the next suggestion would be to just use that header but it's pretty blue and has a dent. Don't want to do a wrap.

I know I could take a dremmel with a metal wheel, put a series of small slit cuts in it. Probably put 3 heavy hose clamps on it try to maintain concentric expansion and put the manual expander in it and get out large enough, than go back with the mig machine and weld all the slits, grind it all down and make it pretty, but that's way too much work to save $60.00. I tend to over think in fabricating. I am looking for way to make to easily make them in the futiure if needed.

That's why I guess I was kind of asking if it seemed feasible to just slit it, expand it and put a thin sleeve or sealent in it to attach.

Thanks again for the link.

After looking at the Ryca adaptor and having given it some thought I have come to a fresh prespective on the whole thing. You can buy little adaptors at the Pep Dudes for going from 1.75" OD to 1.875" ID. It just takes cutting the bent pipe shorter and a quick bead to attach the adaptor to the bend. I really would like it to be longer than the Ryca. My local muffler guy bends the pipe and charges me almost nothing. This brief discussion opened my eyes to other possibilities. I still might buy a Ryca to try it though first though.

I don't quite understand all the issues of needing adapters to mount mufflers.

When I mounted our well-loved Dyna muffler, I did have some trouble with sealing the size mismatch. There is a bump on the inside of the muffler that kept it from sliding on far enough to slip past the reduced diameter section of the header.

I finally said the heck with it, I'll never be remounting a stock muffler, so I chopped about 1 inch off the end of the header pipe. I also loosened the header bolt clamps. The muffler slid on and clamped nicely. I was able to put one bolt into the rail and connect it to one of the muffler bracket holes. I lined everything nice and straight and tightened the header bolts, muffer clamp and bracket bolt.

I had a nice tight connection and mount all in a nice straight line. The muffler exit did point a little at the brake arm, but I never had a problem with it, except for a little soot on the lever.

I liked the look of this set up a lot better then using an angled adapter, which I think kicks the muffler out and down at a strange looking angle.