diamond jim wrote on 05/20/09 at 09:22:45:

if you end up using the "smoke wrench separation technique" listen for a "tink" that sounds different than the ones from pipe expansion... that'll be the bond failing.... that's when you wrestle the headpipe free

DrunkenDwarf wrote on 05/20/09 at 16:37:56:

ok, od is 1 5/8... thats the rough id of 1 3/4 od exhaust tubing... so, hit your local purveyor of auto part, and get as short a length of 1 3/4 as they sell... you only need a few inches... use 2 clamps(1 for each joint, headpipe to your new piece, new piece to muff) make it long enough you can get both on and sealed (dont crowd the clamps)... use the factory end on the headpipe, and if your cut is a little offsquare on the other end, its hidden inside the muff inlet... after you get it all lined up and together loose, loosen up the headpipe retaining bolts at the head, and then tighten everything in sequence, starting at the head, and ending at the muff support.... if you're gonna do the 7 degree bend, then just get the whole shebang at a muffler shop...


edit... i just looked at your new pic, and re=read your dimensions... the 7/16 long section of 1 5/8(the smallest diameter piece of pipe, left in pic) is the headpipe.... you then have a cylindrical sleeve(a couple inches long, heading right in the pic), that ends in a shoulder, then the curve of the outer pipe of the header... the id of the adaptor piece you are fabbing has to fit the od of that larger section behind the 7/16 long stub.... it has to butt against the shoulder at the right end of it in the pic.... the 7/16 long stub isnt long enough to clamp to, it will always leak if you clamp there... so, pull out your calipers again, and measure that cylindrical section just to the right of the stub in the pic.. that will be the id of the front of your adaptor... the other end of your adaptor will be 1 3/4 od...   now for the explanation of the solution and problem... the muff mount bracket, and the rail for the bolt on the muff kept the muffler from actually sealing on that cylindrical section, as the mount kept the muff too far to the rear...the muff inlet should have butted against that shoulder, it didnt in your pics....the short sleeve you are fabbing fits over the full length of the headpipe, from that shoulder to the tip, plus a couple inches to go in the muff inlet... that allows the adaptor you fabbed to seal on the headpipe, then the muff to seal onto the adaptor, and the rail slot to align with the mount for the muff... your finished piece should be somewhere around 5-7 inches long(length of headpipe tip to shoulder, plus depth of inlet nipple in muff, subtract a half inch for fitting, equals the length of your adaptor piece...) im hoping this verbose explanation clarifies what im talking about, as opposed to just further confusion....lol

beer can sounds ideal - aluminum melts at 660C, engine gets no hotter than 400F (about 200C).  Can coating will smoke off fast.

not Busch!  PAABBBSSTTTT BLUUUUUEE RIBBONNNNN!    (Dennis Hopper quote from Blue Velvet.  no motorcycles)

ero4444 wrote on 05/20/09 at 18:49:57:

Actually, I think all I have are bottles. That probably wouldn't work as well.

-D. Dwarf

DD,

Take your muffler canister and your header pipe to a muffler shop.  They'll fix you right up with a custom adapter pipe, and with two harley 1 3/4" muffler clamps, you will be golden.  And once this is done, you should not have any more leaks.  Trying to find a premade adapter pipe is a waste of time, don't ask how I know.  Using a beer can as a gasket is a stop gap solution at best.  Custom adapter pipe is the way to go.

You do not need the 7 degree bend in the pipe.  Just clean your brake arm off once in a while.

I was just thinking about revisiting this as I still have some backfiring issues.  When I first got my bike I had the same problem, I had a longer reducer though.  Here is what I did:

1) Took the whole exhaust off.  used WD40 and a rubber mallet to drive the reducer tight into the harley muffler and clamped it on.  No play, no gaps.

2) I wrapped muffler tape around the bottom of the header where the reducer slides on.  You wont get a tight fit because the reducer is standard and the header is metric.  The muffler tape creates a wide seal for two reasons.  1) it allows a snug fit on the reducer to prevent air leaks.  2) its wide enough to allow the reducer to be slightly angled away from the chrome part of the header.  The slight angle is needed to allow you to bolt down the muffler, other wise its to turned in and rubs on the brake cable.

The end result is pretty good.  I think I still have a small leak so I was thinking about pulling it off and making a slice one the reducer so when I clamp it down the metal compresses tight to the muffler tape.

Or after reading this hell I may take it to a local muffler shop lol.

DD......

Just get the oldest guy in the shop to do the work, and park the bike beside him so he won't have to walk too far......Should be no real drama involved in the operation to speak of - it's all pretty basic stuff for a muffler shop (ever had a look at some of the bendy tailpies on cars? - they have to fab up those sometimes too)

The 7 degree bend is there so that your new muffler will NOT point at the brake arm ... hence, no wiping soot and carbon off it for the rest of your life.

on my install the muffler (a dyna) sits far enough back that i can only get one mounting bolt in it using the stock SUZ braket, but is certainly seems solid enough.  The Dyna is waaaay lighter than the stock pipe,

Good luck on getting it hung on the bike....