The CB1100 Community Forum

Hi all, thanks for this great place to discuss the Honda CB1100. I purchased my 2013 CB1100 pre-owned and it had a roshi RS3 muffler on it.

The Rs3 is a good muffler, not to loud but a good sound. I wanted a look similar to the original muffler but slightly louder but not droning or irritating around my neighbors or when riding for a long distance.

So I started a search to find just the right muffler at a reasonable price. After looking for several days and finding nothing that met all my requirements, I decided to take a chance and fabricate one to my liking. I admit that this solution will not be for everyone, but it meets my needs and the design is what I had in mind.

I chose a 29" megaphone 4" muffler for a Harley FLH. I chose this one because to has a constant rate size reduction all the way to the 1 7/8" inlet. Also it has a double wall and perforated baffle built in and can be cut off to length while still not being to big to fit to the 2 1/4" rs3 adapter pipe. The end caps can be removed (a must) and replaced with different style end caps.

If you do this project with the standard exhaust you would have to have an "S" pipe bent at the muffler shop and then cover it with a chrome pipe cover.

Things you will need, preferred:

*Drill press or hand drill
*Drill bits suitable for stainless steel
*Band saw or powered saws all or hacksaw
*4" cut-off wheel
*metric allen wrenches
*Metric socket set
*Hole saw kit
*Pop rivet tool and 3/16"X1/4 or 3/8" pop rivets alum. or stainless
*Exhaust repair kit with heat activated wrap
*Hydraulic press

Start by removing the rs3 muffler:



Then remove the rs3 adapter pipe and cut off the very end where the spring attachment is using your bandsaw or hacksaw then re-install the adapter pipe. That gave me a 2 1/2 inch pipe, the exact size of the new muffler after I cut about five inches of it off:

[url=http://s38.photobucket.com/user/penguin7009/media/9adapter%20pipe%20cutoff_zpswsiicev1.jpg.html]

After cutting off the new muffler to the desired length (mine was 24") cut the outside only, about 1 1/4" to expose the inside and then slot the end about 1" with your cut-off wheel so you can clamp it onto the 2 1/4" adapter pipe in the previous step.

[url=http://s38.photobucket.com/user/penguin7009/media/8cut%20end%20of%20new%20muffler_zpshkgkohzy.jpg.html]

Use the left over section of the new muffler you removed to cut four sections of pipe for a spacer around the inside of the end of the pipe and drill four holes 3/16" and pop rivet them in place. Be as neat as possible as some of this may show.

I had the original Honda Muffler which had been damaged, so I cut the welds on the hangar bracket and removed the bracket to use on the new muffler:

[url=http://s38.photobucket.com/user/penguin7009/media/10remove%20original%20mount%20fitting_zpsxudsk0mp.jpg.html]

Drill three 3/16" holes on each side of the original bracket to mount the new muffler with pop rivets. I use an exhaust repair kit which has epoxy tape which when heated activates and makes a strong seal to further help with holding the mounting in place and insure the pop rivets didn't loosen. Cut several thickness of this tape and install it between the original bracket and the new muffler after you have trial fitted the muffler to the bike and marked where you want the bracket to fit.

[url=http://s38.photobucket.com/user/penguin7009/media/exhaust%20repair%20strip_zpstnni6vgl.jpg.html]

Bracket:

[url=http://s38.photobucket.com/user/penguin7009/media/10remove%20original%20mount%20fitting_zpsxudsk0mp.jpg.html]

I purchased a stainless steel 2 inch to 2 1/2" exhaust butt end clamp at the auto supply:

[url=http://s38.photobucket.com/user/penguin7009/media/exhaust%20clamp%20end%20on_zpseoaoqm3n.jpg.html]

Cut it in half with one side longer than the other using your band saw:

[url=http://s38.photobucket.com/user/penguin7009/media/cut%20off%20exhaust%20clamp_zps0ks4e2oa.jpg.html]

Finish the edges to remove the burrs and install the muffler. In my case the sound was so loud that it sounded like an old chevy 283 with dumps. So I needed a baffle. If you have an original Harley factory baffle it would work great. But I had to make one. So I cut a piece of 1 1/4" conduit about 19" long and drilled a series of hole along the length within 16" all the way around. I purchased an 1 1/4" freeze plug and using my hydraulic press and a 1" socket and extensions I forced it down half way into the pipe.

I used the original rs3 outlet pipe which was held in by two bolts and clamped it together with a stainless steel clamp. There is sufficient room at the outlet of the muffler for the clamp to fit. I then wrapped the baffle material at each end of the baffle using the mat material and .050 welding wire I had around the shop.

[url=http://s38.photobucket.com/user/penguin7009/media/DSC04822_zpsqetocy2d.jpg.html]

I then re-installed the muffler and the sound was perfect. It's quiet when idling with a burbling sound and when you get on it the sound is like the Rs3, when coming down in the gears there is a burbling sound with a slight roaring in the deep mellow sound range.

The finished product:

[url=http://s38.photobucket.com/user/penguin7009/media/new%20exhaust%20rear_zpsoged71za.jpg.html]

[url=http://s38.photobucket.com/user/penguin7009/media/new%20exhaust%20side_zpsadzyg0pq.jpg.html]

Sound video: [url=https://youtu.be/_vhEtx4g_Qg]https://youtu.be/_vhEtx4g_Qg

ralph

Not really sure how you are trying to post your pictures, but it's not working.

(10-17-2015, 03:52 AM)Randy B_imp Wrote: [ -> ]Not really sure how you are trying to post your pictures, but it's not working.

Yea, having trouble posting. I don't know how to delete the post and start over. The pictures are showing up in different places in the body of the text and some of the pictures are the same. I must be doing something wrong.

Maybe a moderator will delete the post for me, looks like I'm not qualified to post multiple pictures.

ralph

Well, regardless of the picture posting problems (like I should talk ) The finished product looks pretty dang nice to me!

(10-17-2015, 04:43 AM)Lord Popgun_imp Wrote: [ -> ]Well, regardless of the picture posting problems (like I should talk ) The finished product looks pretty dang nice to me!

Thanks, popgun. I think I missed some of the picture code or something. Maybe I'll try again when I get time.

ralph

(10-17-2015, 03:38 AM)Ralph_imp Wrote: [ -> ]Hi all, thanks for this great place to discuss the Honda CB1100. I purchased my 2013 CB1100 pre-owned and it had a roshi RS3 muffler on it.

The Rs3 is a good muffler, not to loud but a good sound. I wanted a look similar to the original muffler but slightly louder but not droning or irritating around my neighbors or when riding for a long distance.

So I started a search to find just the right muffler at a reasonable price. After looking for several days and finding nothing that met all my requirements, I decided to take a chance and fabricate one to my liking. I admit that this solution will not be for everyone, but it meets my needs and the design is what I had in mind.

I chose a 29" megaphone 4" muffler for a Harley FLH. I chose this one because to has a constant rate size reduction all the way to the 1 7/8" inlet. Also it has a double wall and perforated baffle built in and can be cut off to length while still not being to big to fit to the 2 1/4" rs3 adapter pipe. The end caps can be removed (a must) and replaced with different style end caps.

If you do this project with the standard exhaust you would have to have an "S" pipe bent at the muffler shop and then cover it with a chrome pipe cover.

Things you will need, preferred:

*Drill press or hand drill
*Drill bits suitable for stainless steel
*Band saw or powered saws all or hacksaw
*4" cut-off wheel
*metric allen wrenches
*Metric socket set
*Hole saw kit
*Pop rivet tool and 3/16"X1/4 or 3/8" pop rivets alum. or stainless
*Exhaust repair kit with heat activated wrap
*Hydraulic press

Start by removing the rs3 muffler:



Then remove the rs3 adapter pipe and cut off the very end where the spring attachment is using your bandsaw or hacksaw then re-install the adapter pipe. That gave me a 2 1/2 inch pipe, the exact size of the new muffler after I cut about five inches of it off:

[url=http://s38.photobucket.com/user/penguin7009/media/9adapter%20pipe%20cutoff_zpswsiicev1.jpg.html]

After cutting off the new muffler to the desired length (mine was 24") cut the outside only, about 1 1/4" to expose the inside and then slot the end about 1" with your cut-off wheel so you can clamp it onto the 2 1/4" adapter pipe in the previous step.

[url=http://s38.photobucket.com/user/penguin7009/media/8cut%20end%20of%20new%20muffler_zpshkgkohzy.jpg.html]

Use the left over section of the new muffler you removed to cut four sections of pipe for a spacer around the inside of the end of the pipe and drill four holes 3/16" and pop rivet them in place. Be as neat as possible as some of this may show.

I had the original Honda Muffler which had been damaged, so I cut the welds on the hangar bracket and removed the bracket to use on the new muffler:

[url=http://s38.photobucket.com/user/penguin7009/media/10remove%20original%20mount%20fitting_zpsxudsk0mp.jpg.html]

Drill three 3/16" holes on each side of the original bracket to mount the new muffler with pop rivets. I use an exhaust repair kit which has epoxy tape which when heated activates and makes a strong seal to further help with holding the mounting in place and insure the pop rivets didn't loosen. Cut several thickness of this tape and install it between the original bracket and the new muffler after you have trial fitted the muffler to the bike and marked where you want the bracket to fit.

[url=http://s38.photobucket.com/user/penguin7009/media/exhaust%20repair%20strip_zpstnni6vgl.jpg.html]

Bracket:

[url=http://s38.photobucket.com/user/penguin7009/media/10remove%20original%20mount%20fitting_zpsxudsk0mp.jpg.html]

I purchased a stainless steel 2 inch to 2 1/2" exhaust butt end clamp at the auto supply:

[url=http://s38.photobucket.com/user/penguin7009/media/exhaust%20clamp%20end%20on_zpseoaoqm3n.jpg.html]

Cut it in half with one side longer than the other using your band saw:

[url=http://s38.photobucket.com/user/penguin7009/media/cut%20off%20exhaust%20clamp_zps0ks4e2oa.jpg.html]

Finish the edges to remove the burrs and install the muffler. In my case the sound was so loud that it sounded like an old chevy 283 with dumps. So I needed a baffle. If you have an original Harley factory baffle it would work great. But I had to make one. So I cut a piece of 1 1/4" conduit about 19" long and drilled a series of hole along the length within 16" all the way around. I purchased an 1 1/4" freeze plug and using my hydraulic press and a 1" socket and extensions I forced it down half way into the pipe.

I used the original rs3 outlet pipe which was held in by two bolts and clamped it together with a stainless steel clamp. There is sufficient room at the outlet of the muffler for the clamp to fit. I then wrapped the baffle material at each end of the baffle using the mat material and .050 welding wire I had around the shop.

[url=http://s38.photobucket.com/user/penguin7009/media/DSC04822_zpsqetocy2d.jpg.html]

I then re-installed the muffler and the sound was perfect. It's quiet when idling with a burbling sound and when you get on it the sound is like the Rs3, when coming down in the gears there is a burbling sound with a slight roaring in the deep mellow sound range.

The finished product:

[url=http://s38.photobucket.com/user/penguin7009/media/new%20exhaust%20rear_zpsoged71za.jpg.html]

[url=http://s38.photobucket.com/user/penguin7009/media/new%20exhaust%20side_zpsadzyg0pq.jpg.html]

Sound video: [url=https://youtu.be/_vhEtx4g_Qg]https://youtu.be/_vhEtx4g_Qg

ralph

Here's a close up view:

[url=http://s38.photobucket.com/user/penguin7009/media/finished%20exhaust%20quarter_zpsaosbdmv2.jpg.html]

ralph

Looks really good, Ralph.

Looks good Ralph, same power? Increase? How does it sound?

(10-17-2015, 07:07 AM)capttwb136_imp Wrote: [ -> ]Looks good Ralph, same power? Increase? How does it sound?

Its hard to say with no dyno but the power seems the same or slightly better, the sound is beautiful.

The way the baffle works is the exhaust has to go into the end of the baffle then out through the 3/16" holes then back in through the baffles on the other side of the freeze plug and then out the muffler.

If you wanted more sound you could increase the size of the baffle holes to 1/4".

ralph

how about a video with some sound? And a couple red line shifts :-)

(10-17-2015, 07:45 AM)HikerToo_imp Wrote: [ -> ]how about a video with some sound? And a couple red line shifts :-)

When my Videographer daughter comes around I will try to do that, until then maybe I can post a short video.

ralph

(10-17-2015, 07:45 AM)HikerToo_imp Wrote: [ -> ]how about a video with some sound? And a couple red line shifts :-)

Here ya go: https://youtu.be/_vhEtx4g_Qg

ralph