Looking for exhausts that are compatible with my 84’ CM450E

[TomatoThePotato]

Hey y’all, looking to replace my current exhaust on my CM450E. I have a few holes near the very end of the muffler (?) and I’m not sure if this will affect my performance since its at the very end, however I’m worried my local motorcycle shop might fail my safety inspection. So I’m in the market to see if I can just fix the whole exhaust system or maybe the muffler itself (I’m not very familiar with exhaust terminology, my first time working with exhausts). What bikes exhausts would be direct swaps?

 

[LongDistanceRider]

Someone just replaced their mufflers with Sportster units which is a good option since they slip onto the power chamber. It's not this one but this is similar

'78 CB400T, hollow exhaust collector?

In the process of restoring my bike, I ended up needing to take the exhaust off. Well, since the bike had been sitting outside (under a shed roof) for nearly 30 years, the amount of rot on the OEM power chamber was significant, and there were even internal components that are loose. So, I...

www.vintagehondatwins.com

 

[Maraakate]

Yes, a bike I worked on recently had sportster mufflers and it worked quite well. A bonus is they're cheap because Harley guys take them off right away and put louder exhausts on it

 

[J-T]

I have used them. Their sound is a bit more throaty than stock.

 

[Maraakate]

Yes not a stock sound, but I don't think they sound too bad honestly. I was surprised. Not a bad deal if you just need something cheap and easy that works.

 

[TomatoThePotato]

Someone just replaced their mufflers with Sportster units which is a good option since they slip onto the power chamber. It's not this one but this is similar

'78 CB400T, hollow exhaust collector?

In the process of restoring my bike, I ended up needing to take the exhaust off. Well, since the bike had been sitting outside (under a shed roof) for nearly 30 years, the amount of rot on the OEM power chamber was significant, and there were even internal components that are loose. So, I...

www.vintagehondatwins.com

Looking more into it, is there a specific year I should be looking into? I found these on Facebook marketplace for cheap.

 

[LongDistanceRider]

Those will work fine. You'll need to fabricate a mount for the left side since Sportster's mount on the right side.

 

[Bobs twin]

Hey y’all, looking to replace my current exhaust on my CM450E. I have a few holes near the very end of the muffler (?) and I’m not sure if this will affect my performance since its at the very end, however I’m worried my local motorcycle shop might fail my safety inspection. So I’m in the market to see if I can just fix the whole exhaust system or maybe the muffler itself (I’m not very familiar with exhaust terminology, my first time working with exhausts). What bikes exhausts would be direct swaps?

View attachment 32492View attachment 32493

I replaced my original mufflers on my 81 CB400T with sportster slip-ons, and they work very well.
I had to have a stepped pipe made to go from the 1.75" needed for the Harley muffler in to the 43mm power chamber under the Honda.
My stepped connector is 4.5" long and did the trick.
I also made hangers out of 1/8" aluminum to hang from the Honda foot peg bolt to the two threaded nuts on the Harley muffler.
I have a drawing of the hanger bracket also, if interested.
Bob

 

[TomatoThePotato]

I came across a motorcycle shop the other day that had a CM450E exhaust in stock. I later found out that it was actually off a CX500, and I was wondering if this one would still work? Realistically I only need the mufflers but I really like the headers on this one, so I was wondering if i could directly swap the exhausts.

 

[LongDistanceRider]

There are 2 power chamber to engine mounting tabs needed, the ones on that one aren't useable. I doubt the pipes will fit yours, muffler should work though

 

[TomatoThePotato]

Alright, will try mufflers. I know taking them out is going to be a pain so any advice on that would be appreciated. If this doesn’t work, I’ll look more into sportsters mufflers l and possibly go bob’s route.

 

[EzPete]

Alright, will try mufflers. I know taking them out is going to be a pain so any advice on that would be appreciated. If this doesn’t work, I’ll look more into sportsters mufflers l and possibly go bob’s route.

Due to the Twisted Twin on the CX series, those headers won't work - they'd kick the pipes out at a really funky angle.

I just got done tearing down 3 sets of those. Removing just the mufflers is pretty straightforward if they haven’t fused totally to the H-Box (there should be a gasket ring between them that helps prevent this, which appears to be in place on that set, so here's the easy way:

Lay down an old tshirt or junk towel
Place the header side down on that, lean the mufflers up against the wall or bench edge, etc.
Soak the seam between the muffler and the HBox with your PB, Kroil, 3-1... whatever you're using for rusty stuff. gravity will be your friend here
Loosen bolts holding those clamps on (Might have to soak and wait on those)
Pry open the clamp with a big flathead - get it loose enough to get out of the way
Say a little prayer to the corrosion gods that the exhaust gasket isn't fused to the H Box
Here's the part that's hard to describe...

Stand the system up on the bend of the headers and then facing it, go kind of duck footed and use your body weight to pin the headers down
Grab a muffler and start twisting, once it starts to rotate a bit, keep it rotating and pull up
Watch your teeth - when it lets go you can slam yourself straight in the jaw and it leaves a bruise that is somewhat weird to explain at work.. or so I've heard...

If there's no rotation, soak it down again and hit it with some heat - that material on the H box is paper thin right there and will expand, rotate, keep it up until it frees up. You'll have to remove the gasket before re-use on your bike, new ones are readily available. (Part number 18392-MG7-750)

Do you mind sharing a pic of the headers? Or you can PM to me - on the CX's they get dinged all the time, which is why they're always mummy wrapped and I might be interested in buying those from you. Each one of my sets and each of them has one or both sides that look like garbage.

 

[TomatoThePotato]

Due to the Twisted Twin on the CX series, those headers won't work - they'd kick the pipes out at a really funky angle.

I just got done tearing down 3 sets of those. Removing just the mufflers is pretty straightforward if they haven’t fused totally to the H-Box (there should be a gasket ring between them that helps prevent this, which appears to be in place on that set, so here's the easy way:

Lay down an old tshirt or junk towel
Place the header side down on that, lean the mufflers up against the wall or bench edge, etc.
Soak the seam between the muffler and the HBox with your PB, Kroil, 3-1... whatever you're using for rusty stuff. gravity will be your friend here
Loosen bolts holding those clamps on (Might have to soak and wait on those)
Pry open the clamp with a big flathead - get it loose enough to get out of the way
Say a little prayer to the corrosion gods that the exhaust gasket isn't fused to the H Box
Here's the part that's hard to describe...

Stand the system up on the bend of the headers and then facing it, go kind of duck footed and use your body weight to pin the headers down
Grab a muffler and start twisting, once it starts to rotate a bit, keep it rotating and pull up
Watch your teeth - when it lets go you can slam yourself straight in the jaw and it leaves a bruise that is somewhat weird to explain at work.. or so I've heard...

If there's no rotation, soak it down again and hit it with some heat - that material on the H box is paper thin right there and will expand, rotate, keep it up until it frees up. You'll have to remove the gasket before re-use on your bike, new ones are readily available. (Part number 18392-MG7-750)

Do you mind sharing a pic of the headers? Or you can PM to me - on the CX's they get dinged all the time, which is why they're always mummy wrapped and I might be interested in buying those from you. Each one of my sets and each of them has one or both sides that look like garbage.

Okay, will try this all out. Thank your for the in depth explanation. So twisting the exhaust is the way to go, got it. And sure I’ll send pics of the headers here.


After i did a lil polishing with 0000 steel wool and some mothers aluminum polish, to see how they fix up. A bit of pitted, but overall not bad.

 

[EzPete]

I don't know what it is with those CX's, but the left side always corrodes much more than the right - from front to back all three of mine have more corrosion in the shock bolts, frame mounts, headers, footpegs, etc on the left. Guess I'm going to have to make the decision to either have mine replated or paint them. I don't need any Phineas and Ferb toilet paper on my headers and I was hoping by some miracle yours had escaped that.

There's a second way to pull them, if that initial route doesn't work, requires two people or a lot of weird blocking and bracing to do the same thing with the pipes horizontal.

Ideally, you can get those mufflers off without damaging the HBox. Given that the left doesn't have lay down damage and only the rust pitting, if you can preserve the H Box and there's nothing rattling around in there, the headers and box in that condition are going for about 85-100 on ebay right now

 

[TomatoThePotato]

I don't know what it is with those CX's, but the left side always corrodes much more than the right - from front to back all three of mine have more corrosion in the shock bolts, frame mounts, headers, footpegs, etc on the left. Guess I'm going to have to make the decision to either have mine replated or paint them. I don't need any Phineas and Ferb toilet paper on my headers and I was hoping by some miracle yours had escaped that.

There's a second way to pull them, if that initial route doesn't work, requires two people or a lot of weird blocking and bracing to do the same thing with the pipes horizontal.

Ideally, you can get those mufflers off without damaging the HBox. Given that the left doesn't have lay down damage and only the rust pitting, if you can preserve the H Box and there's nothing rattling around in there, the headers and box in that condition are going for about 85-100 on ebay right now

Phineas and ferb lol. Yeah I didn’t want to exhaust wrap it either, I really like a chrome exhaust, i am really bummed that I cant use the headers though, they are 1000x better than my current headers.