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Freebird
08-29-2006, 11:31 PM
VR-Exhaust Combiner Chamber Repair

A.K.A. Fixing the Rattle in The Baffle

by Robert Trim

My second 1987 Yamaha Venture Royale Exhaust baffle
began the 'rattle samba' a short time back.
The devil is in the details and a picture is worth a thousand....
well you get the drift.

Here's a way I did the surgery

1- You have to drop the entire exhaust system.

a- remove mufflers on both sides first. 2 bolts on
the rear of the chamber and 2 bolts half way down
the mufflers accessible through the passenger's foot rest supports.

b- remove the side panels, both sides.

c- remove the lower fairing legs, both sides. The lower air dam
and plastic cross brace.

d- remove allen bolts holding headers to front cylinders.

e- loosen 2 bolts in the clamps holding the combiner
chamber to the front pipes.

f- There are FOUR attach points holding the exhaust collector box to the bike. The TWO front attach are released by removing two 12mm NUTS located on a bracket near the front of the collector box which hold it to the bottom of the engine case. The TWO rear attach points are released by removing two 12mm BOLTS for the exhaust clamps at the bottom end of the rear headers; these are best removed by using a 10" socket extension angled up at a 45 degree angle on either side of the center stand.

g- now the fun part... the chamber is not going to come easy.
Use a pry bar on either side and work it lose from the rear
headers. You will need to work the front headers lose and
free so the chamber can drop down.

2- Cut open the chamber.

3- Remove needed baffle screen to get at the baffle.
4- Remove the baffle.

5- Bend opening shut.

6- Have someone weld it shut. It's stainless steel and needs
someone with experience.

7- reinstall in reverse order. Make sure you put the chamber
in place WITH the front headers attached. An extra set of
hands is vital at this point.

Here's some of those thousand word photos....

http://www.venturerider.org/baffle/StrippedSideSm.jpg

Side plastic, mufflers and front headers off.

http://www.venturerider.org/baffle/LowerSectionSm.jpg

http://www.venturerider.org/baffle/BafUpperBolts.jpg

It's easier to remove the parts with the bike on the center
stand until you get to the rear header clamps. Put it on the
side stand, use a mirror and drop light on the floor and look
up between the frame tube and slightly forward. About the angle
of the arrow you see above. The right side is easier to fine
than the left so start with that one first.

http://www.venturerider.org/baffle/MirrorSm.jpg

http://www.venturerider.org/baffle/ScreenIn.jpg

http://www.venturerider.org/baffle/CutoffToolSm.jpg

The chamber is on it's back and this is 2 steps into the
opening process. I used a cutoff tool to
cut it open. WARNING... USE safety glasses and
leather gloves when using the cutter.
The above photo shows the left
baffle liner screen already cut out and you can see the
down pipe from the rear header connections.

http://www.venturerider.org/baffle/BentUp.jpg

Bend it open ONLY as far as you
need to gain access to the baffle. I needed it 90 degrees
open to get the cutoff tool in. If your baffle is flopping fairly
freely (very common), open a little and grab with vice grips,
twist and pull hard.

http://www.venturerider.org/baffle/SideOpen.jpg

Here both screens are cut out.

http://www.venturerider.org/baffle/ECUbaffleSm.jpg

My baffle had it's welds in place but was stress fractured
along the bottom. I simply used the cutter to finish the break.

http://www.venturerider.org/baffle/BaffleOut.jpg

The rest of the bracket is fine so I leave it. It's spot welded
top, bottom and in the front. With the chamber now open for
air flow, this now exactly like the crossover pipes put between
headers of a dual exhaust system on a car. The VR will now breath
much easier.

http://www.venturerider.org/baffle/DrillEndCut.jpg

Carefully fold the flap back and work it as straight and as
close to original placement as possible. Use a drill bit to
create a termination hole at the end of each cut. Stainless will
crack from any sharp point even after it is welded.

http://www.venturerider.org/baffle/ReadyForWeldSm.jpg

Ready for welding. A good welder will suggest that after
welding the seam, a second layer of stainless be added over the
seam. This will pretty much assure that the weld will outlast
the bike.

http://www.venturerider.org/baffle/CrackedBracket.jpg

It is important to check for other cracks. This is the chamber
mounting bracket on the top of the chamber. I did not see this
until I gave it a good cleaning. This is a common problem.
Get it welded as well.

http://www.venturerider.org/baffle/BigWeld.jpg

Big seam welded to perfection by the students at Salt Lake
Community College's welding program. Good people to know.

http://www.venturerider.org/baffle/BracketWeld.jpg

Bracket crack all fixed.

http://www.venturerider.org/baffle/ChamberReady.jpg

Ready to go back in place. It's better to approach this from
the right side of the bike. Slip the chamber back on the rear
header down pipes and thread the bracket bolts on a few turns.
Install the front headers into the chamber front inlets. This is a
process of seating the pipes into the chamber and, at the same time,
making sure the front header seats align flush. Soon as you get it
dialed in, put the alan nuts on the front headers to hold them in place.
Tighten the chamber bracket nuts. Then tighten the clamps to the front
headers, then the header-to-head alan nuts. These are kind of a bear because there is a frame cross brace just 'almost' out of the way. You need a 5/16" longer length alan wrench to get it started.
Install the mufflers. Replace the plastic parts and you're good to
go. One additional tweak it to drill out the 2 baffles in the mufflers.
You'll need a 1/2" drill bit welded to an 18" rod. Punch a few holes in
the baffle on each end of the muffler for more air flow.

Hope this helps if you need to do baffle surgery.