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Rear Exhaust Manifold

Started by artbone, September 22, 2017, 04:08:52 PM

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artbone

I know this has been covered but I'm trying to install the rear Y manifold and I can't get it to tighten up. I wiggle the manifold up to the exhaust outlet, put the two washer like things on the pipe followed by the two copper O-rings, shove it home in the outlets, put the clamps on and tighten and, if you don't hold it the Y manifold will fall out of the outlets..

What am I doing wrong?
Art Bone

'83 Yamaha Vision in the Classic Black and Gold  Running
'82 Yamaha Vision Running
'74 Norton Fastback - Colorado Norton Works #26  Running
'73 Norton Interstate  Running
'75 Triumph T 160  Running
'62 Harley Davidson Vintage Racer
'61 Sears Puch  Running
'15 Triumph Scrambler
'17 Honda Africa Twin
94 Kawasaki KLR 650

jefferson

More than likely the copper rings are worn out. You might try annealing them and see if that helps. I used some high temperature red silicone that sealed things up pretty good.

PwrManDan

Silly question but do you have the washer and the copper o ring inside the clamp?

Rikugun

#3
It's been a while but as memory serves:
A leak free assembly requires the copper gasket "A" be a light press fit on the wye pipe. If not, the assembly will fall apart. The copper gasket seals against the face of flange "B" and the OD of the wye pipe "C". You can see a chamfer on the wye ends to get the copper gasket started but it can't be a slip fit.

Start with the stub pipes "E" installed in the cylinder head with their gaskets. Slip the chrome stoppers on the wye pipe and press the copper washers in place. Note the direction of the chrome stoppers - they have a shape the copper seals nest in. Slip the wye into the ends of the stub pipes up to the copper gaskets.

Capture flange "B" and chrome stopper "D" with the sheet metal clamp. Note these last steps require small hands and profuse cursing. Some advocate the use of red RTV but I'm guessing those installations may have a poor mechanical fit of the copper gasket. The shape of the clamp draws the chrome stopper forward sealing the copper gasket against the stub pipe flange. Again, if the copper gasket is loose on the wye, gases will leak past at the wye pipe OD. Noise and eventual burning of the chrome stoppers will occur.

Install the muffler assembly.

Photo Credit: Bobby Crabb

It is far better to grasp the universe as it really is then to persist in delusion, however satisfying or reassuring.  Carl Sagan

artbone

From your excellent picture and discription I've got everything right except when I get the clamp as tight as it will get the pipe is still loose. The chrome plate is flat against the flange on the stub. The only thing I can figure out is that I'm using the wrong O-rings. I'll be in Atlanta next week so I'm going to try to source new O-rings. I've got a friend who works for Yamaha's headquarters here so maybe he can help.
Art Bone

'83 Yamaha Vision in the Classic Black and Gold  Running
'82 Yamaha Vision Running
'74 Norton Fastback - Colorado Norton Works #26  Running
'73 Norton Interstate  Running
'75 Triumph T 160  Running
'62 Harley Davidson Vintage Racer
'61 Sears Puch  Running
'15 Triumph Scrambler
'17 Honda Africa Twin
94 Kawasaki KLR 650

jefferson

If you are talking about the copper rings when you say o-ring then the last I heard they are not available, hence the anneal and high temp silicone suggestion. If you find some by chance I'm sure there are others that would be interested.

Ron_McCoy

Remove battery box and overflow bottle and ignition box for room to work. Assemble exhaust system. Leave the clamp in place but do not tighten completely. You want it to position the chrome o-ring retainer, but not clamp it tight. Tack " D " to the Y pipe with the welder of your choice, preferably MIG (Y pipe is fairly thin). Disassemble and weld "D" to Y pipe. Leak will be cured and assembly of the exhaust system is much simpler. This has worked for nearly 30 yrs on my Vision with no problems.

QBS

Ron, does your system ensure that, what I call "the silver disc", will not become flame cut and lead to chronic and ever worsening exhaust leaking?  If this were to occur the silver disc would have to be replaced.  It has been my experience that even the faintest hint of flame cutting renders a silver disc of no value.

artbone

Ron, I like that suggestion but why couldn't you assemble the whole thing on the bench, weld it, and then assemble it? Can you still get the Y pipe through the opening with the flanges welded on?

I've been looking on ebay and there are any number of "copper exhaust gaskets" for sale but I can't tell if they are the right ones. Some look correct but some look like they have asbestos. I think those go inside the exhaust ports.

Does anyone know the thickness of the copper material? I might attempt to make some. San Miguel has a lot of artist and there are art supply stores that sell copper wire. It shouldn't be hard to make a jig and make some. I wonder if brass would work instead of copper. I've got some 3/16 brass brazing rod.
Art Bone

'83 Yamaha Vision in the Classic Black and Gold  Running
'82 Yamaha Vision Running
'74 Norton Fastback - Colorado Norton Works #26  Running
'73 Norton Interstate  Running
'75 Triumph T 160  Running
'62 Harley Davidson Vintage Racer
'61 Sears Puch  Running
'15 Triumph Scrambler
'17 Honda Africa Twin
94 Kawasaki KLR 650

Ron_McCoy

Bob, I've done the exhaust on three visions this way and no problems with flame cutting. That was why I did the first one. I had a chronic exhaust leak at the rear cylinder and found flame cutting. I anneal the copper rings and they seal nicely. The silver discs can no longer leak at the Y pipe and doesn't seem to leak at the outer edge.
Art, by assembling the exhaust system on the bike with the mufflers mounted on the head pipes and bolted to the rear foot peg mounts, the Y pipe is held in the correct relationship so that the silver discs are welded square with each other assuring a good seal.
I have made the copper rings out of copper round stock, but I don't have the diameter in my notes. It was a common size though. I silver soldered the ends after cutting them at an angle. The silver solder didn't hold up well, but they didn't leak noticeably. I did replace them at the next tear down.

Good luck,

Ron

PwrManDan


artbone

I found 2 sellers on ebay. The cheapest was $19 each and he's got 4. I hate to pay that much for something that simple but what can you do?
Art Bone

'83 Yamaha Vision in the Classic Black and Gold  Running
'82 Yamaha Vision Running
'74 Norton Fastback - Colorado Norton Works #26  Running
'73 Norton Interstate  Running
'75 Triumph T 160  Running
'62 Harley Davidson Vintage Racer
'61 Sears Puch  Running
'15 Triumph Scrambler
'17 Honda Africa Twin
94 Kawasaki KLR 650

PwrManDan

I swear those sellers know which parts exactly are worth their weight in gold.

The Prophet of Doom

Someone here had a big bag of those copper rings and was giving them away to anyone who asked.  They are cheap in quantity from china I guess


On my 400 I welded the flange to the Y pipe and got a very good seal with just a smear of gasket goop
http://ridersofvision.net/rovforum/index.php?topic=15058.msg138223#msg138223






Rikugun

Quote from: PwrManDan on September 27, 2017, 08:18:42 PM
I swear those sellers know which parts exactly are worth their weight in gold.
Yup. It's almost as if they are Visionaries themselves.
It is far better to grasp the universe as it really is then to persist in delusion, however satisfying or reassuring.  Carl Sagan

PwrManDan

POD - in that same post you replied with a possible source, did that ever amount to anything?

http://www.aircraftspruce.com/catalog/eppages/an900.php

fret not

Rings can be cut from copper plate.  Annealed copper is fairly soft and reasonably easy to deform for a seal.  It might work.
Retired, on the downhill slide. . . . . . . . still feels like going uphill!

The Prophet of Doom

Quote from: PwrManDan on September 28, 2017, 08:44:41 PM
POD - in that same post you replied with a possible source, did that ever amount to anything?

http://www.aircraftspruce.com/catalog/eppages/an900.php
I didn't need them due to the flange.


Rikugun

Quote from: PwrManDan on September 28, 2017, 08:44:41 PM
POD - in that same post you replied with a possible source, did that ever amount to anything?

http://www.aircraftspruce.com/catalog/eppages/an900.php

Compared to the OEM's I measured, the 1 1/16" are the closest ID (1.0625") without being too big.  For reference, I measured the ID of a used OEM set @ 1.105" - 1.108". If you baked them in an oven they may slip on.
It is far better to grasp the universe as it really is then to persist in delusion, however satisfying or reassuring.  Carl Sagan

jefferson

A friend just used some parts that he got at the auto parts store. He had to do some work to make them fit as the id was too big. He is going to get me the part number and I will post it when I get it.