HOW TO: Remove baffles from stock pipes, pics and vids!!!

[timmo]

so i couldn't find any info on how to do this, so i tackled it myself. i'm very pleased with the results, even though i didn't remove as much as i originally intended. the bike sounds great, nice deep throaty sound and still has good bottom end. this is only one way to do it, so keep an open mind and improve where you see fit. i haven't taken it for a real ride yet, so there may be some carb tweaks to compensate for less back pressure, however, most of the baffles are still gonna be there, just the end cap was removed.........

(all pics and videos were with my iphone, sorry for the sound quality)



so my bike is a 78 xs650. here's a pic to show what the pipes are that came on mine.

and here's what my tips looked like

you can cut out the back in two different methods:

use a 3 1/4 inch hole saw which is really close and leaves less to grind away

or you can use a drill and make a hole. then use a jig saw or a dremel tool and cut around the outside of the cap

next you need to grind the outlet of the original port. there is a seam there that joins the pipe to the cap, grind enough away until you can knock out the big part of the cap

next take your dremel and cut off as much as the original inner pipe to help hide it from the rear

then using a grinder attachment on your dremel or drill, start smoothing out the leftover metal to the outer pipe to make a smooth appearance

remarkably, rustoleum high temp bbq paint looks just like carbon build up. so after you smooth out all your cuts and it is nice, spray a little in there to hide the bare metal

and here's your final product

here's a video of the stock pipes, no mods at all

and here it is with the end caps removed, but the inner baffles still in place

add any info you may have to improve the mod

the picture with single pipe inside of large housing pipe my single pipe is loose and sticking out the back of whole muffler , should i cut rest like you did or buy new ? muffler s ?

 

[deshi]

what jet size if I am not running air filters and just stacks?

 

[slamm]

I'm new to the forum and have just purchased a 1983 XS650 Heritage Special. I've heard that the 83's run leaner because of emissions. I was wondering how cutting out the back of the muffler on my bike would affect jetting. I've been told that any modifications to this year would create headaches that would take forever to figure out the right jetting.

My exhaust is in really good shape but I'd like it a little louder. I don't want to spend a lot of money on a dino. I think it's about $150 for one session.

Would appreciate any help you can give.

 

[fredintoon]

On the stock Special exhaust...I took a four foot length of 5/8ths ground rod and probed the opening in the rear of the exhaust. About a foot and a half to two foot in there's a stop. I then drove the rod through the stop on both mufflers. A bit more free flow and a bit more tone.

Hi nj,
Did all 3 of our XS650s with the ol' pointy bar trick.
I used a broken Dodge Dart front suspension torsion bar.
It has a big hex end for a 3lb club hammer to pound on, the bar is an easy fit into the muffler tube and the jagged spiral fracture end where the bar broke off works great to punch through the inner baffle.
did my '84 Heritage mufflers first, nice mellow sound afterwards.
Did my son's '80 Special next, sounded nicely mellow too, but louder than the '84.
Finally, the '79 Special, still mellow but louder yet.
What I reckon is, Yamaha made the stock mufflers a bit quieter every year so the exact same pointy bar trick was less effective on the newer bikes.
And Hi slamm, the pointy bar trick will work for you with far less hassle than carving into the mufflers with a hole saw and a Dremel.
But like I told my son when we did ours, there's no easy way to reverse this procedure.

 

[nj1639]

Hey fellas, my adventures in exhaust have finally reached their apex with an equivalent set of Mikesxs Commando headers and muffs for my '77 and the stock headers cut aft of the frame mount with a set of full length Dunstall muffs for the '83.
Quite happy with the sound and performance of both bikes.

 

[5twins]

Slamm, yes, your bike was set up very lean from the factory. It has been reported by many that going up one size on the mains will help even a totally stock machine. Start modding things and you will definitely need to do some carb jet tinkering. It's not that difficult though and the sizes that work for most are well documented here. Go to the tech section and read up on the carbs. And forget about dyno time, it's not needed. You are the dyno, lol.

 

[slamm]

Funny you mentioned the Dodge Dart. I work at a Dodge dealership.
After you poked a hole in the baffle with the torsion bar, did you make any carb modifications on the '84? Or did you not need to?

 

[slamm]

5twins- I've jetted a VTX1300 once but never a dual carb bike. I'm inexperience and very apprehensive with twin carbs. Thanks for reassuring me; I thought the bike had been set up to run lean. Thanks for the advice. I'll check out the Tech Section -Carbs. This forum loaded with good information.

 

[fredintoon]

Funny you mentioned the Dodge Dart. I work at a Dodge dealership.
After you poked a hole in the baffle with the torsion bar, did you make any carb modifications on the '84? Or did you not need to?

Hi slamm,
no, the sparkplugs were the same greyish tan after the T-bar job as they were before; that was years ago and the bike runs as well now as it did then.
Mind you, my bike is a Canadian model and I don't think their carbs were leaned out as much as the US models.
A US carb may well need to be set a tad richer after opening up it's exhaust.

 

[jussumguy]

STOP IT!!!!
Before you guys "modify" the last remaining set of origional pipes I'll trade a brand new stock pipe that was completely gutted by its previous owner.
I have an 83 that needs a clean set.

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[fredintoon]

STOP IT!!!!
Before you guys "modify" the last remaining set of origional pipes I'll trade a brand new stock pipe that was completely gutted by its previous owner.
I have an 83 that needs a clean set.
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Hi jussum,
too late, mate. My pointy bar adventure was 10 years back and was irriversable from the moment the last baffle died.
Your set is completely gutted, nothing in there at all?
NOS stock pipes are getting real hard to find and appallingly costly if you do find a set.
Perhaps your least expensive option if ALL of your internals are gone it to retrofit new innards into your nice chrome?
Unless you are going concours and must have absolute stock MikesXS sells nice pipes that are not too loud at a reasonable cost.

 

[arbea]

On the stock Special exhaust...I took a four foot length of 5/8ths ground rod and probed the opening in the rear of the exhaust. About a foot and a half to two foot in there's a stop. I then drove the rod through the stop on both mufflers. A bit more free flow and a bit more tone.

I did the same thing and it works great, I tried it on my 80 also beside my 78

 

[dps650rider]

Here's what I did to mine, just a bit louder and deeper and less blat that if a hole is driven through the inside baffle plate. Once I cut the bottom of the muffler open I enlarged the holes in the baffle plate and added/enlarged ones in the tube. When I was done I welded the flap on the muffler closed again and painted it. Since this is on the bottom you can't see it.

I also have a threaded 3/8 hole in the inside plate with a bolt in it that I can remove with a long extension and socket if I want it to bark more. Most of the time I leave them in.

 

[MattXS83]

The metal plate on the back of the muffler is soft enough that you can take a flat screw driver and a hammer, and just go around it like a chisel and punch right through the plate. You will also need to go around the pipe too. When you get the plate off, if you have one of the newer nonslip cutting discs from Dremel, to cut the pipe shorter, you can do the whole job in a few minutes and only use one or two discs. I have done this on a couple of xs's. It will give you a much better sounding bike for zero dollars.

Did you have to adjust the carbs after doing this?