Ironhead How to mount muffler

[SD_Mike]

I have a 72 XLCH that came with aftermarket slip-on mufflers. The mufflers have a threaded stud on them that bolts to the support tube. I just bought a set of replica 65231-65a mufflers and was surprised that they don't have studs on them. How do these mufflers mount? I looked at the parts book, but I can't figure it out. It looks like I use a 65275-62 clamp for the front of the front muffler, and a 65276-62 clamp for the front of the rear muffler. But then what? Does the 65279-57 clamp go around the middle of the muffler and then mount to the support tube? Also, what's the flat spot on the muffler for?

[Magneto Sportster]

The pinch bolts used in the 3 rear clamps also attach to the support tube. (The two on the rear muffler thread into the tube, the bolt in the muffler body clamp on the front muffler just passes through the hole in the tube with a nut on it). The header clamp on the front muffler just pinches, but does not attach to the tube.

[The Doctor71]

Not sure what you're using for a support tube...... BUT I suspect you currently have an aftermarket one.

If that is the case, you'll need the correct support tube..... p/n 65316-65A for the clamps to line up correctly. (other prefixes like -65 or -65B would likely work too).

[SD_Mike]

Thanks, it is starting to make more sense. Looks like I will need something like this clamp set: https://thegasbox.com/products/1965-...aust-clamp-set

Anyone know if the clamp sets come with bolts, or do I need to find those, too?

Good point on the support tube. I wonder if I will need new pipes, too, as I know they are aftermarket. And here I thought this would be as simple as pulling off the old mufflers and swapping in the new ones . . . .

[SD_Mike]

Found this diagram. It's for the interconnected pipes, but I suspect the muffler mounting is the same.



I've got the clamps on order from Gasbox. Now I need to find the support tube, my current one is definitely different than stock. I see a few on ebay, and VTwin makes one, too.

[Serious Blac]

There is a clamp on the cross-over! Well that explains a lot, thanks.

[SD_Mike]

I got the new support tube installed and received the clamps from Gasbox. The good news is that it looks like my current front pipe will work fine.



The bad news is the rear pipe will not work.



The pipe ends too high, so that the clamps will not reach the support tube.



More good news is that Bill's Custom Cycle has NOS rear pipes in stock, so I just placed the order. Turns out this little project is way more involved than I expected.

[sportsterpaul]

If the rear pegs and swing arm didn’t interfere with your current exhaust you could make extensions for the clamp mounts, just saying...

[SD_Mike]

Originally Posted by sportsterpaul

If the rear pegs and swing arm didn’t interfere with your current exhaust you could make extensions for the clamp mounts, just saying...

I thought about that, and probably would have gone that route at least temporarily if the pipe wasn’t readily available. But the whole reason for this project in the first place was to get the exhaust closer to original, both in sound and appearance. I never liked how close the old muffler was to the rear foot pegs. And rigging something with the new muffler to make it work would have the rear muffler mounted horizontally, rather than angled slightly up. I’ll be happier in the long run with the right pipe.

[The Doctor71]

I may be wrong but just a minor heads up.....

The #3 clamp in your diagram.... front clamp from header pipe to frame appears to be installed to the upper motor mount bolt.

Normally that front clamp is installed to the lower motor mount bolt.

EDIT: Based on your pics, it looks like either location work ok. Of course, do whatever works for you and your ride.