Personalize your Sportster
Blog BOM Custom Design
Garage OSARM Repair Smörg

1972 Sportster exhaust

Mount an old stylish factory exhaust to make the bike quiet.
Harley made a one-piece muffler exhaust system for the 1972-1976 model years. It will fit on most Iron Sportsters, in this case, my 1977 daily driver. The tubes are necked down to 1.5 inches and the large muffler shared by both cylinders makes for a very quiet bike.

Besides the quiet, another nice thing is that there is no goofy separate bracket. The muffler has a large tab that mounts directly to the frame.

The muffler is PN 65431-72, front pipe is 65447-70, rear is 65495-70, the small clamps are 65519-70. There are heat shield covers and goofy 70s mod finned exhaust clamps, but I didn't mount any of that.
Here is the 1972 exhaust on my 1977 Iron Sportster. There is still a rear footpeg missing, the spring return interfered, I am still sussing it out but I am confident I can get it back on the bike. I also have not cleaned the pipes yet with brake cleaner or carb cleaner.

My 1977 is cut up pretty radically. It has a steel kickstarter mount I designed so it doesn't need a sprocket cover. It has a dry clutch so you can see my home-made lever actuation on the rod coming out of the tranny sprocket. I have welded a footpeg mount on the frame and am running the 1975-76 footpeg and rear brake setup. I moved the battery to the front since I got tired of my jeans getting acid holes and I needed the space to mount and oil filter.

I also mounted flat-side 5-gallon big-bike tanks, after a fling with Shovelhead tanks. A 2-gallon tank does not get it for a daily driver.
Bottom of first column move down to the left

Here is what I had on the bike, rusty staggered aftermarket duals. The baffles came loose in both mufflers, which I fixed by running a 3-inch drywall screws into the middle from underneath, until one caught a baffle and quieted things down for a few months.

It funny how you can have a great-running bike that starts in two kicks or less, but if the exhaust is rusty or the tank is spray-can they call it a rat bike. If you take some craptastic junker and have new pipes, paint and a pretty Live-to-Ride chrome air filter, then all you hear is "Totally nice bike, dude."


Here is the ultra-cool muffler setup. You can't see it, but there is a big bracket/tab on the back so this mounts directly to the frame. Its a little restrictive, but I like the quiet. Any idiot can mount drag pipes and make the engine un-tunable.
move up a little to the right move down to the left
Here is the front pipe. I got the whole setup from Bill's Custom Cycles in Bloomsburg, PA.

Here are two front pipes. The upper one has a tab on it in the middle that is supposed to pick up a motor mount bolt. It also has a little dent in the back to clear the footpeg. I tried it but used the other.

This is the small clamp that goes between the muffler and pipes.
move up a little to the right move down to the left
The factory chrome on these pipes is very nice. OEM Harley parts are usually better-made than aftermarket stuff when it comes to pipes.


This bike has seen me through thick and thin. I only had to push it once, when the 1/4-28 screw holding the ignition flyweights snapped from the weights hitting the backing plate of the points. Cone motors all do this-- that is why this one has electronic ignition. I got tired of putting new flyweights into the ignition.


I position these aftermarket clamps to hide the bolt but allow me to reach it like this.
move up a little to the right move down to the left
The aftermarket staggered duals are held with a T-bolt at the muffler. They take a 1/2 inch wrench.
This is pretty ratty. even for me.1972_Sportster_exhaust_10Same deal for the rear pipe clamp, hidden but accessible.
border bar
move up a little to the right move down to the left
The rear bolt is more of a pain. Its harder to reach, and sometimes the chain has chewed it up. No more of these hassles with the 1972 factory setup.
Get that clamp all the way off.1972_Sportster_exhaust_13
Dropping the kicker can make it easier.
border bar
move up a little to the right move down to the left
I had extended the slots in the old pipe, it allowed them to clamp better.

9/16 for the bracket bolts.1972_Sportster_exhaust_16Evil wrench keeps changing direction.
border bar
move up a little to the right move down to the left

Its astonishing what a pain this wrench is. The little lever is perfectly designed to flip the other way when you choke up to use it fast. The buyer at Craftsman must never have twirled a wrench in his life.


Here is the evil monstrosity in all its glory. I Like the wrenches that have the tri-ridges on the back and even some other ones with this goofy lever are better designed so you are not constantly changing the direction while you try to use it.

This is when I think a Snap-On wrench might be a dandy investment.
move up a little to the right move down to the left
Old pipes off.
The bike without any exhaust. 1972_Sportster_exhaust_22My spiffy steel kick-start mount so I don't have to run a sprocket cover. This one does not break if you drop the bike on the kickstarter lever.
move up a little to the right move down to the left
Trial fitting of the front pipe.

You can just make out the tab where it lines up to the motor mount bolt.

1972_Sportster_exhaust_25Trial fitting of the rear pipe. So far so good.
move up a little to the right move down to the left
The old clamps, some new ones I had, and a factory-style clamp lower left.

1972_Sportster_exhaust_27Anti-seize on the bolt threads and where the head runs on the clamp.

1972_Sportster_exhaust_28A little persuasion is OK in exhaust work, but I didn't need to in this job.
move up a little to the right move down to the left
Remember to put the clamps on.

1972_Sportster_exhaust_30The front pipe would not slip in the muffler. I tried anti-sieze.

I ground the seam down flush.
move up a little to the right move down to the left
Then I just tried the other front pipe it slipped on perfectly. No dent in the back to clear the footpeg on this one. This turned out to be critical since the pipe has to slide all the way over the muffler. Good view of the bracket.

I could not get one bolt in as I groveled on the floor so it went in the wrong way. Bolt heads face out to clear the chain.1972_Sportster_exhaust_34
The rear peg interferes.
move up a little to the right move down to the left

Heck with it, see if I can get away with it, I loose-mount the rear pipe. The key lesson here is that you can loose-mount the muffler first. I initially tried installing the pipes and mating the muffler in one fell swoop. Bad idea.


All work on Harleys get to a point called "The explosion of tools". This job should have taken two wrenches and an Allen wrench. By the time its over half the tool box will be on the floor. Now I need a 1/2 inch socket since the peg bolt has a jam nut.
move up a little to the right move down to the left
Then back to the box to get a Channel-Lock to hold the peg bolt.

1972_Sportster_exhaust_38Now I can't get the bolt out-- homicidal urges as I push on the muffler with my knee and pull on the bolt, as if I am trying to mount the bike like a rutting hog.

1972_Sportster_exhaust_39 At last, a loose fit-up. Homicidal urges fade. Looks pretty good. All is well.
move up a little to the right move down to the left
The front pipe does not line up perfectly but close enough.

Same for the rear, not quite right. The muffler is still loose.
A little persuasion and the rear is OK.
move up a little to the right move down to the left
The front does not line up perfectly.

But its close enough, I just snug it up.

1972_Sportster_exhaust_45You can hide the clamp bolt but get to it like this.
move up a little to the right move down to the left
OK, more explosion of tools, now I have to get a 9/16 short socket to get the muffler mount on. Now that the muffler tends to stay in place, I turned around the rear bolt I had stuck in temporarily. Now the head of the bolt is under the chain where the chain is less likely to hit, as opposed to the nut side where the bolt sticks out.

Yes, there was pinching of fingers and profanity and the required groveling where I laid on the floor next the bike. I stupidly gave away all my fasteners before moving to Florida, so I don't even have new lock washers.

1972_Sportster_exhaust_46 My Hansen socket trays pay for themselves-- easy to get the right one.
move up a little to the right move down to the left
The front is still marginal but will have to do. I can't see how to fit these unless I take a torch to the pipe, which would ruin the chrome. Be careful, you can tighten these clamps so hard it cracks off the cast iron head nipple. I did this to the rear nipple on my 1979 bobber.

The finished bike, other than the rear peg. Many enthusiasts say these pipes are ugly, but I think they are great, especially in view of their superior engineering. Sure the bike looks better with pretty chrome, but I like the quiet and the way these don't need a separate bracket. The 1.5-inch pipes make it easier to get to things and I like their looks as well. More elegant, less troglodyte.
move up a little to the right This is the end.

This post is in these categories:

border bar
Bottom of first column This is the end.