Topic: Exhaust split colars dont seem to fit. Cant get exhaust on. *NOW WITH PICS

[Gorms]

Went to install the exhaust on my cb550 today and got confused (I didnt take an pictures when I took them off).  The 8 semi-circular "split collars" (as the microfiche calls them) go around each header tube with the non-flared end pointing to the exhaust ports and the flared ends touching the finned "joints" (as the microfiche calls them).  These are the finned clamps that bolt to the studs.  Whats confusing is that the flared ends of the split collars dont fit inside the lip in the joints.  It looks as though the split collars are of a larger diameter than the inner lip of the joints.  The bike was in shambles when I bought it but I remember the exhaust fitting OK.  Do I need smaller diameter split collars?  Secondly, do MAC and Kerker exhausts come with new collars?

[mystic_1]

Flip them over, they're backwards.

mystic_1

[CrashBar]

Did you try taking the finned collar off the pipe and assembling that way, just to check the size?   I had one that would not go together, I "dry fit" it like that and it was obvious that rust or some deformation was keeping it from going in.  I hit it with a file until the diameter was smaller, and it went together fine.

[1timduke]

If you're installing and don't have 4 hands and twenty fingers, use a little cellophane tape (pipes need to be clean) to hold the flanges on and keep them from falling out, also helps to turn the joint between the half moons vertical.   The tape will burn off once the bike heats up.

-Tim

[Gordon]

Flip them over, they're backwards.

mystic_1

Yup...

[MoTo-BunnY]

If you're installing and don't have 4 hands and twenty fingers, use a little cellophane tape (pipes need to be clean) to hold the flanges on and keep them from falling out, also helps to turn the joint between the half moons vertical.   The tape will burn off once the bike heats up.

-Tim

+1   I used rubber bands to do the same thing - helps immeasurably (although kinda stinky as they burn off. . . lol)

[Hush]

Hmm rubber bands or cellotape, now why didn't I think of that?
Oh yeah and if yoy want your "crush" gaskets to stay in place while you muck around with these collars, just use some light grease or even light glue to hold them.

[MoTo-BunnY]

Hmm rubber bands or cellotape, now why didn't I think of that?
Oh yeah and if yoy want your "crush" gaskets to stay in place while you muck around with these collars, just use some light grease or even light glue to hold them.

I used a wee bit of Permatex 3H on each side, to glue in them in real good. Plus, that is the only gasket stuff that won't burn off - it's real high temp aviation stuff, used on air cooled engines frequently. (I know of it, from the VW world). It sealed it all up really nice and finally killed off a tiny exhaust leak that had always annoyed me.

[Gorms]

I will try again but I definately appears that the curve that the split collars make is of a much larger diamter than the curve of the lip that it fits into.  I would have to bend the colars quite a bit to have them fit in there

[Gorms]

...and I am unclear as to how to flip them over.  The flared end goes into the finned "joint" no?

[MoTo-BunnY]

Maybe a visualization will help?

Also, the collar pieces won't touch each other, when they go in, there is a bit of space between them.

[Gorms]

Here are some pictures.  The first shows that I have two different types/sizes of split collars.  I only have 2 of the larger flared ones so I assume those are incorrect.




This picture shows that the smaller collar does not fit inside the lip of the joint.  Do I bend it?  I tried with pliers and while it can be done, its not very flexible at all.




I am going to be buying a new exhaust (probably a MAC but maybe a Kerker but I dont know where to find them).  Do any of these exhausts come with new collars that would make my life easier?

[mystic_1]

In your very last pic, pick up the collar half and turn it upside down.  The non-flared end will fit the collar perfectly.

mystic_1

[Gorms]

After a search I found that the orientation I have set up there is correct.  Is this wrong?  Il go try that.

[mystic_1]

Well, the way that works is the right way

mystic_1

[Gorms]

The microfiche confirms that the flared ends face AWAY from the engine.  I put it together ignoring the fact that the flared ends dont fit into the joints and of course I am getting all sorts of leaks.  Probably because the flare on the header pipes isnt big enough for the collars to press against and the fact that there is nothing keeping the collars from staying in contact wiht the pipes (besides the tape that I have on there now).  There has got to be a better way to hold an exhaust to an engine!

[Hush]

...and I am unclear as to how to flip them over.  The flared end goes into the finned "joint" YES?

Yes that part you have right.
It would appear that the previous owner got some 650 or 750 collars mixed in with your ones, there definately should not be that much difference.
When you got the bike they had probably just forced those in which would have worked just not as originally intended.
For a cheap fix just to tide you over as you figure out which replacement exhaust system you want, file/grinde the larger flanges down to fit.
You don't mention any "crush gaskets" are you fitting some new ones, this will ensure a good leak proof seal, the old ones may look like part of the head port, you may need to have a hook around in there with a sharp object to get them out after 30 odd years.
If you can't find them and you don't have crush gaskets you can use a tube of gasket goo, it seals up pretty good too.

[MoTo-BunnY]

you might want to get a full, new set of the split collars, as they should all be the same size - looks like someone picked up some junkyard parts at some point, mixed up different sets, or something?

Exhaust Joint Collar  18233-107-000 - $3.42 each (8 needed)  
(priced at Honda Direct Line http://www.hdlparts.com/fiche_section_detail.asp

You also should use tape or rubber bands to hold the colors tight on the exhaust pipe for installation and then check in there with a flashlight to make sure they stayed in place. I ended up having to use a couple of shims to force the split collars outward, as a couple kept slipping when I would tighten the cast iron collar thingy. That will cause leaks. Also, watch the torque you put on the exhaust nuts, it's very low - only 5.7 to 8.6 ftlbs (.8 to 1.2 Kgm). If someone has torqued them down harder before, they can deform badly.

Also, I installed mine as per the micro fiche / parts diagram which also matches what I saw in the OEM Honda manual so dunno why you want him to "flip" the pieces?

Here is another, clearer picture (gawd, I wish someone would make nice high-rez, all in one .pdf parts book scans!) direct from the OEM Honda CB500/550 manual, I just took. It's a CB550F but the exhaust collars and whatnot, are the same.

(note that Honda apparently changed their mind on the orientation of the gaps in the split collars - here they are 3 and 9 o'clock where the other image they are at 12 and 6 o'clock. I did mine like this image has them where the gaps are next to the studs)

[Gorms]

May I ask what keeps the colars "hooked" on to the pipe lips?  Seem like (and I think mine are) they would want to slip off and get pushed into the  gasket.

[Toxic]

The very end of your exhust header should have lip on it.
-finned collar pushs down on the split keepers
-the split keepers push down on the lip
-the lip then applys pressure to the seal.

I the end of your header doesn't have a lip, that's a problem.

Post a pic of the end of your header where it inserts into the head.

A header with no lip uses a different type of mounting system.

[Toxic]

Look at MotoBunny's pic. Your header should have a lip like that.

[Gorms]

They have a lip, but not much of one.  More like a small flare.  I will post a pic of the exhausts.

 So theres nothing keeping them from slipping off this lip huh?

How crucial is it to have a 100% leak free exhaust?

[MoTo-BunnY]

May I ask what keeps the colars "hooked" on to the pipe lips?  Seem like (and I think mine are) they would want to slip off and get pushed into the  gasket.

That's why you use tape or rubber bands to keep them there. The non flanged of the collars end gets pressed up behind the trumpet like lip at the end of the exhaust pipe. The flanged end of the split collars, set in that groove of the cast iron collar. The cast iron collar pushes the split pieces up against the exhaust pipe trumpet end lip, which then goes up against the copper exhaust gasket and the head.

If you are reusing the split pieces, especially, where they may have become deformed somewhat, they will want to collapse in up against the pipe then then there is no pressure from the cast iron collar being transferred to the trumpet end of the exhaust pipe via the split collars, and thus leaks occur. Also, the non-flared ends  of the split collars, can sometimes slip and go up and over the trumpet end of the exhaust pipe into the head area - again causing a leak.

What I ended up doing on one stubborn pipe, was construct two semi-circle shims out of aluminum, that fit between the split collars (towards the flanged end of the split collars) and the exhaust pipe, so that the whole assembly was "tapered" - bigger at the end that goes into the cast iron collar and smaller at the end that touches the copper gaskets. Then, I wrapped the assembly (split collars, shims, then exhaust pipe ends) with thin but strong rubber bands (black silicone hair bands for doing corn rows, etc.. .  .lol) to keep it all in place. The shims forced the split collars outward so they stayed up against the cast iron collars, upon tightening. I rode it up to temp for a bit, went home and then the shims were removed (so that everything heated and expanded correctly). I could have actually left the shims in but since they hung out a bit and were visible, I removed them - just yanked them out with pliers.

Here is a picture of the shims: (make as many sets of these as you need, use the rubber bands or tape trick, and those split collars HAVE to line up right if you are careful. Again though, I suggest you might want to buy a whole set of matching split collars, as mine were all identical and it looks like you have two different types, for some reason.

[MoTo-BunnY]

They have a lip, but not much of one.  More like a small flare.  I will post a pic of the exhausts.

 So theres nothing keeping them from slipping off this lip huh?

How crucial is it to have a 100% leak free exhaust?

Again, the split shims press up BEHIND the trumpet flare thingy. The tape/rubber bands hold the pieces together as you tighten it all up. The pressure from being tightened down holds it together.

It is VERY important to have a leak free exhaust as otherwise you will have back fires, uneven running cylinders, and eventually can burn an exhaust valve from higher temps on the leaking cylinder.

[mystic_1]

Also, I installed mine as per the micro fiche / parts diagram which also matches what I saw in the OEM Honda manual so dunno why you want him to "flip" the pieces?

Because 1, they obviously didn't fit the way he was trying, 2, sometimes the diagrams are wrong, and 3 the way that works is the right way, and 4, some honda exhaust systems have different orientations for these parts.

Of course, having the correct collars to go with the retaining rings would help a lot

May I ask what keeps the colars "hooked" on to the pipe lips?  Seem like (and I think mine are) they would want to slip off and get pushed into the  gasket.

Wait a minute.  The end of the pipe should be as large as the gasket, no smaller.  If this is so than there should be no way for the collars to come into contact with the gasket since the pipe's flange covers it completely.  If this is not the case than you have bigger problems.


mystic_1