Mufflers on your Honda CB360 are often rusted through, missing, or replaced with an ill-fitting aftermarket exhaust. While our replacement mufflers are not factory clones, they retain a period-correct upswept look and can be installed cleanly with the correct hardware, bracket setup, and gaskets.

Why these mufflers work so well on the Honda CB360

Original Honda mufflers are incredibly difficult to find in usable condition, with most available sets either being very expensive or rusted beyond use. Even when an aftermarket muffler physically fits the motorcycle, it may not look correct, mount properly, or allow the engine to run as intended.

These replacement mufflers are sized appropriately, sound great, and retain the upswept appearance of the original CB360 exhaust system. The left and right mufflers are side-specific, so make sure each muffler is installed on the correct side of the motorcycle. The mufflers also feature completely mechanical baffles that are removable, which makes future cleaning or repacking possible.

Parts Needed

• Pair of CB360 Common Motor mufflers
• Muffler mounting hardware - Comes with the Common Motor mufflers
• Stainless T-bolt clamps - Comes with the Common Motor mufflers
• Graphite crush gaskets for header pipe to muffler connection
• Copper crush gaskets for header pipe to cylinder head
• Anti-seize compound
• Red thread locker
• 3/4 inch automotive heater hose
• Clear nail polish, paint, or another rust-preventive coating for modified universal bracket edges

Tools Needed

• Metric hand tools
• Allen wrench for baffle screws
• Flathead screwdriver
• File
• Triangular file
• Hacksaw
• Drill
• Center punch
• Step drill bit
• Adjustable wrench
• Ruler
• Pliers

What hardware is included with the mufflers

Muffler hardware overview

Optional Recommended Parts

Note: The graphite crush gaskets are one-time-use parts once fully compressed.

Inspecting and servicing the removable baffles

These mufflers use a removable mechanical baffle retained by three Allen screws.

If you plan to inspect or repack the baffles, doing so while the mufflers are new makes access easier before heat cycles, carbon buildup, and corrosion make the assembly harder to disassemble.

The mufflers contain a completely mechanical baffle, but additional fiberglass packing can be wrapped around the center section if a quieter exhaust note is desired.

Baffle service notes

• Remove the three Allen screws carefully.
• Pull the baffle assembly from the muffler.
• Inspect and clean the mechanical baffle as needed.
• Add fiberglass packing around the center section if a quieter exhaust note is desired.
• Reinstall the baffle securely using anti seize compound on the 3 Allen head baffle mounting screws.
• Do not overtighten the baffle screws.

Header pipes and exhaust gaskets

Before fitting the mufflers, inspect the header pipes and replace any worn sealing parts.

Preparing the cylinder head connection

1. Remove the header pipe from the cylinder head.
2. Inspect the cylinder head exhaust port for the old copper crush gasket.
3. Use a small flathead screwdriver or pick to locate the gasket if carbon buildup makes it difficult to see. Remove the old gasket.
4. Install a fresh copper crush gasket.
5. Apply a light amount of anti-seize to the exhaust stud threads.
6. Reinstall the header pipe with the split exhaust collars with the beveled side facing outward and the flat side facing inward.
7. Start the exhaust nuts just tightly enough to hold the pipe in place. Leave enough movement in the header pipe for final muffler alignment.

Preparing the header pipe

1. Clean carbon and residue from the muffler end of the header pipe.
2. Slide the graphite crush gasket onto the end of the header pipe.
3. Confirm the graphite gasket sits square against the header pipe stop ring.
4. Apply a small amount of anti-seize to the T-bolt clamp threads.
5. Apply a small amount of anti-seize beneath the T-bolt head where it bears against the clamp.
6. Place the T-bolt clamp over the muffler connection.
7. For the CB360 installation shown, position the T-bolt clamp with the bolt at the bottom.
8. If the muffler end is slightly too small, gently open the slots with an adjustable wrench so the muffler can slide over the graphite gasket.

Mounting the Mufflers on the CB360

How to install the mufflers with factory brackets

Keep in mind that exhaust fitment on vintage motorcycles is rarely exact. Header pipe length, pipe bends, frame mounting points, factory brackets, and even the welded mounting channel on the replacement muffler can vary slightly. We recommend you mock up the complete exhaust system before making final modifications or tightening the hardware.

Reusing the factory CB360 muffler brackets

The factory brackets are the preferred option because they provide a simple two-point attachment between the muffler and bracket while locating the exhaust from the original Honda frame mounting point. They look very similar at first glance, but they are left and right specific and asymmetrical.

Factory CB360 bracket orientation

• Match the correct bracket to the left or right side of the motorcycle.
• The bracket has a long side and a short side.
• The short side faces toward the rear of the muffler.
• The long side faces toward the front of the muffler.
• The raised reinforced portion of the bracket faces inward toward the motorcycle and frame.

Installation steps

1. Identify the correct left- or right-side factory bracket.
2. Confirm that the reinforced side of the bracket faces inward toward the motorcycle.
3. Position the short end of the bracket toward the rear and the long end toward the front.
4. Install the square nuts into the muffler mounting channel.
5. Install the factory bracket using the bolts, split lock washers, and flat washers.
6. Leave the bracket hardware finger tight.
7. Place the stainless T-bolt clamp over the muffler connection with the bolt positioned at the bottom.
8. Slide the muffler onto the header pipe over the graphite crush gasket.
9. Align the end of the muffler with the edge of the graphite gasket and header pipe stop ring.
10. Do not slide the muffler past or over the stop ring as it will prevent the muffler from clamping the graphite gasket fully.
11. Install the frame mounting bolt through the factory bracket and leave it slightly loose. If using the passenger pegs, reuse the original frame mounting bolts. If not, use the new mounting bolts included with the muffler hardware kit.
12. Adjust the muffler position, bracket position, header pipe, and clamp position until the system sits naturally.
13. Check that the top of the header pipe flows cleanly into the straight section of the upswept muffler without an obvious crooked joint.
14. Snug the T-bolt clamp.
15. Snug the header fasteners at the cylinder head.
16. Tighten the frame mounting hardware.
17. Tighten the bracket-to-muffler hardware.
18. Once satisfied with fitment, remove one bracket bolt at a time, apply red threadlocker, and reinstall.

We recommend the T-bolt clamp be clocked so the bolt faces downward. Make sure the clamp sits evenly around the muffler inlet and does not interfere with nearby chassis components.

Factory bracket modification

The left-side muffler on the motorcycle shown fit correctly using the factory bracket without modification however the right-side muffler required the bracket to be modified because the muffler initially sat approximately 1/2 inch too far rearward to seat correctly against the graphite gasket.

To correct fitment if the muffler does not sit in the ideal spot when test fitting your new mufflers with factory brackets:

1. Leave the header pipe, muffler clamp, and factory bracket loose.
2. Remove the rear bracket-to-muffler bolt.
3. Slide the muffler forward until the muffler inlet reaches the correct position before the header pipe stop ring.
4. Snug the remaining bracket bolt and muffler clamp enough to hold the muffler in its correct position.
5. Confirm that the header pipe and straight section of the muffler align correctly.
6. Loosen the muffler clamp and large frame mounting bracket bolt to remove the muffler and bracket as a unit.
7. Mark the location for a new mounting hole in the factory bracket.
8. Make sure there is adequate material around the proposed hole.
9. Center-punch the hole location.
10. Drill a new 3/8-inch mounting hole.
11. Deburr the new hole.
12. Reinstall the bracket and test-fit the muffler again before final tightening.

Our right-side factory bracket modification measurements

Keep in mind that because exhaust components and replacement mufflers can vary slightly, use the actual motorcycle to locate the new hole rather than relying on a fixed measurement from another bracket. These were the correct measurements for our CB360 right side bracket, but you could find yours to be different for either or both sides.

How to install the mufflers with modified universal brackets

Modifying the included universal brackets

If the factory brackets are missing, the included universal chrome strap brackets can be modified into a solid dual-mount setup using a few simple hand tools.

1. Identify the end holes of the universal strap as hole No. 1 and hole No. 6.
2. Mark the cut location between the two center holes shown during the installation.
3. Use a triangular file to notch the chrome at the beginning of the cut.
4. Cut the bracket with a hacksaw.
5. Deburr the cut edges and round the corners with a file.
6. Enlarge hole No. 1 and No. 6 to 13/32 inch with a step drill bit.
7. Deburr the drilled holes.
8. Seal all exposed raw metal edges and drilled surfaces with clear nail polish, paint, or another protective coating.

Universal bracket modification dimensions

Installing the muffler

1. Install the modified bracket sections onto the muffler with the square nuts and hardware.
2. Position the longer bracket section toward the front of the motorcycle and on the outside.
3. Position the shorter bracket section behind the longer section.
4. Overlap the bracket sections near the frame mounting point.
5. Keep all bracket hardware loose enough to move during alignment.
6. Place the T-bolt clamp over the muffler connection.

7. Slide the muffler onto the header pipe. Align the muffler inlet with the edge of the graphite gasket and header pipe stop ring.

   

8. Do not slide the muffler past or over the stop ring as it will prevent the muffler from clamping the graphite gasket fully.
9. Install the frame mounting bolt loosely.
10. Adjust the bracket overlap and rotation until the muffler sits square on the motorcycle.
11. Move the muffler and brackets forward or backward as needed to establish the correct position at the stop ring.
12. Adjust the bracket angle to establish the correct upswept muffler angle.
13. Snug the T-bolt clamp.
14. Check the alignment between the header pipe and straight section of the muffler.
15. Snug the header nuts.
16. Snug the frame mounting bolt.
17. Tighten the bracket hardware gradually.
18. Make any needed adjustments before final tightening.
19. Apply red threadlocker to the bracket bolts only after the final position is confirmed.

Foot peg clearance note

To use factory passenger peg with the modified universal bracket, additional modification is necessary. Use the longer original mounting bolt when the factory foot peg shares the mounting point. The small locating nub on the foot peg will interfere with the vertical universal muffler bracket. Cut off or bent out of the way to provide adequate clearance.

Final tightening, alignment, and service notes

Final checks

• Correct left- and right-side mufflers are installed
• Muffler is seated correctly before the header pipe stop ring
• Graphite crush gasket is fully contained within the muffler joint
• T-bolt clamp is centered and properly rotated with the bolt facing downward
• Header pipe and straight section of the muffler align naturally
• Header pipe is sealed at the cylinder head
• Muffler bracket is not under unnecessary tension
• Muffler does not contact the frame or other components
• Factory foot peg clears the universal bracket if in use
• All hardware is tightened evenly

Important future service note

If the exhaust assembly needs to come off later, remove the muffler and header pipe assembly from the motorcycle as one piece when possible. Remove the frame mounting bolt that connects the muffler bracket and the header exhaust flange nuts to pull the exhaust system off as a single assembly. DO NOT separate the muffler from the header pipe unless you are prepared to replace the graphite crush gasket. The graphite gasket is compressed during installation and should be treated as a one-time-use seal once fully crushed. Removing the header pipe and muffler together also saves the effort of realigning the complete exhaust system during future engine service.

How to protect the mufflers from stand contact

The factory mufflers used built-in stand bumpers. These replacement mufflers do not. Without protection, the side stand and center stand can strike the muffler and leave dents or marks over time.

A simple solution is to slide short sections of 3/4 inch automotive heater hose over the contact points on the stands.

CMC Recommended heater hose bumper lengths

Use tire lube, soapy water, glass cleaner, or a similar lubricant to slide the hose into place. The hose is a wear item. We typically gets a couple of years of service from these pieces before replacement is needed.

Troubleshooting

The muffler will not slide onto the header pipe

Clean the pipe end thoroughly and inspect the graphite gasket for damage or incorrect positioning. If the muffler end is slightly compressed, gently open the slots with an adjustable wrench just enough for the muffler to slide over the gasket.

The muffler joint leaks

Verify that the graphite crush gasket is properly installed and that the muffler has not been pushed over the header pipe stop ring. Recheck the T-bolt clamp position and clamp tension.

The muffler does not line up with the frame mount

Loosen the entire system again. On vintage exhaust systems, the header pipe, muffler, frame mounting point, and bracket often need to float into position before final tightening. Do not force the exhaust into alignment by fully tightening one component first.

The factory bracket fits on one side but not the other

This can happen because of normal variation in the exhaust components and replacement muffler mounting position. The motorcycle shown required no factory bracket modification on the left side, while the right-side bracket needed an additional 3/8-inch mounting hole so the muffler could move forward approximately 1/2 inch. Test-fit each side independently and modify either bracket if needed.

The muffler sits too far forward or rearward

Loosen the muffler bracket hardware and frame mounting bolt. Move the muffler until the edge of the muffler inlet lines up with the graphite gasket at the header pipe stop ring. With the universal brackets, adjust the overlap and angle of the two bracket sections as needed.

The foot peg interferes with the universal bracket

The factory foot peg will require modification when using the universal bracket arrangement. The locating nub will need to be bent or trimmed so the vertical muffler bracket can clear it. Use the longer mounting bolt if the factory foot peg shares the muffler mounting location.

FAQ

Can I reuse the factory muffler mounting brackets on a Honda CB360?

Yes. The factory brackets are the preferred option. The brackets are left- and right-side specific and must be installed in the correct orientation.

Will the factory CB360 brackets require modification?

Possibly. We recommend test fitting each muffler with the factory bracket before install to see where the muffler sits. If your muffler does not sit at the correct spot, follow our factory bracket modification instructions in the video to mark your bracket and drill a new hole to accommodate the slight difference.

Should I use the metal adapter collars that come with the mufflers?

We do not recommend them when graphite crush gaskets are available. The graphite gasket provides the superior seal and is the method the factory mufflers use between the mufflers and header pipe.

Do I need to replace the copper crush gaskets at the cylinder head?

Replace the copper crush gaskets when they are badly flattened or have been compressed through several header pipe removal and installation cycles.

Can I remove the baffles from these mufflers?

Yes. The baffles are removable and retained with three Allen screws. The mechanical baffle can also be wrapped with additional fiberglass packing if a quieter exhaust note is desired.

Should I use threadlocker on the muffler hardware?

Yes, on the bracket bolts. Apply red threadlocker only after the complete exhaust system has been mocked up, aligned, and placed in its final position.

Can I separate the muffler from the header pipe later for service?

Once compressed, the graphite gasket should be considered a one-time-use seal. Remove the muffler and header pipe together as one assembly when possible.

Do the mufflers work with the factory passenger pegs?

They can, but modification is required if using the universal brackets. The foot peg locating nub will interfere with the vertical universal muffler bracket and will need to be bent or trimmed for clearance.