Headpipe to muffler joint exhaust leak

[JohnSmith123]

I bought an 82 that was missing the exhaust so I got 07-0757 MikesXS chrome headpipes and 07-0114 18" mufflers. The mufflers came with the 3 piece reducer set to go from 1.75" to 1.5". Problem is that no matter how much I tightened the clamp at the muffler to header joint it still puffed exhaust. I then tried heavy duty harley style clamps recommended on this board and it still leaked.
Then I got a pair of 07-4631 one piece 1.75 to 1.5 reducers thinking that was the problem. Well I put them on and when tightened down there is still a 1/8" gap in the reducer where exhaust will obviously leak.

I know I'm probably missing something really simple. Throw some ideas at me guys before I just weld the damn muffler on the header. Thanks!

 

[mrtwowheel]

For a sealer on close fitting pipes I have used wood stove gasket cement. This stuff is messy, cleans up with water or solvent don't remember, cures incredibly hard with heat. This stuff cures into such a rock hard material that disassembly would not be easy at all or maybe not possible at all. At your own risk and last resort.

Scott

 

[5twins]

That's the problem with those reducers, they always leak, lol. You might try filling the "slit" down their sides with silicone gasket sealer. Normally, I don't recommend silicone sealer for any normal gasket or engine sealing surface, but this is an exception. Goop that shit on there. And yes, when I call it "shit", I really mean it, lol.

 

[JohnSmith123]

I've come up with a similar solution. Since the gap is so wide though I made a little "gasket" out of aluminum tape folded up over and over again. Then I gooped a crapload of muffler sealer on everything. I figure the combination of the spacer squeezing the "gasket" and the sealing goop should pretty much seal the leak. If it doesn't it's going to be mig welding time.

It's going to take 24 hours to cure so I should be able to do a test run tomorrow.

Also, why in the heck doesn't anyone make a 1.5 muffler so we can avoid all this BS? I've looked all over and it's all 1.75.

 

[Michaelo]

Sealers are messy, buy some shimming material and make a shim to fit inside the muffler. I did this on my bike with great success. Issues with sealants is they are good for a while but through vibration (which we get plenty of) and heat they fail. A good fitting mechanical interface (shim) will work. It's brass material, it's cheap, and purchase two different thicknesses so you get a nice tight fit.....

 

[JohnSmith123]

Just tested my solution and it works. Used the 07-4631 one piece 1.75-1.50 adapter, aluminum tape "gasket" in the gap, and lots and lots of permatex muffler sealer on everything. Made a mess, but no more leaking.

PS: Definitely throw away the clamp that comes with the mikesxs muffler. The harley style clamp provides way more clamping force.