Baffle not baffle'ing

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Premixer63
Still in the Driveway
Posts: 8
Joined: Sun Nov 20, 2016 6:57 am
Country: USA
Suzuki 2-Strokes: S32-2

Baffle not baffle'ing

Post by Premixer63 »

The right hand exhaust is way louder than the left on my '66 S32-2. But both baffles are in identical shape - like new. There are no header-to-cylinder leaks and no leaks where the header meets the muffler - the noise is coming out the muffler tail. Could there be something going on inside the muffler where the baffle seats in, allowing exhaust gases to bypass the baffle? Any suggestions or advice welcome!

Sincerely,
Baffled

Update - The quiet side baffle is coated with exhaust oil along its entire length, whereas the loud side is dry and slightly rusted halfway along the exit side.
Craig380
Expert racer
Posts: 1250
Joined: Mon Dec 01, 2008 2:52 am
Location: Manchester, UK

Re: Baffle not baffle'ing

Post by Craig380 »

Hi, yes, unfortunately it's quite common for the internal baffle plates in the silencer to come loose, because the spot-welds that hold them in place fail through fatigue / vibration etc. Or the quiet side silencer may have a big lump of carbon / crud blocking the gas outlet.

If you remove both silencers and shine a strong light up both ends, you'll quickly find the problem.

I once had a very weird thing happen on my old GT380 triple - I was giving it some throttle when the engine note changed and went 'dull', and the bike lost power and slowed. "Oh deary me, the poor thing has seized a piston," I thought.

I rode VERY gently home. When I got home, the engine still sounded sweet (no rattles etc) but there were no exhaust pulses from the exhaust for the left cylinder, even though the cylinder was running.

I removed the baffle and there was a big lump of carbon crud that was lodged in the baffle tube, blocking it almost completely. Where it came from, I have NO idea.

So remove the silencers and have a good look and poke around.
1976 GT380 - wounded by me, and sold on
2006 SV650S - killed by a patch of diesel and a kerb in Feb 2019
2017 SV650 AL7 - naked and unashamed
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jabcb
Moto GP
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Suzuki 2-Strokes: 69 T350 thru 75 GT750
Location: southwestern Pennsylvania

Re: Baffle not baffle'ing

Post by jabcb »

The cylinders might be out of balance with the right cylinder producing most of the power & the left getting more oil than it needs.
So a general tuneup might solve this. Start with the points & plugs. And sync & adjust the carbs.

What is the bike's history?
BAS (Bike Acquisition Syndrome) - too many bikes but have room for more

Suzuki:
GT750 2x75
GT550 72 & 75
GT380 72
T500 69 project & 73 project
T350 69 & 71
Honda 85 CB650SC & 86 CB700SC
09 Triumph Bonneville SE
Premixer63
Still in the Driveway
Posts: 8
Joined: Sun Nov 20, 2016 6:57 am
Country: USA
Suzuki 2-Strokes: S32-2

Re: Baffle not baffle'ing

Post by Premixer63 »

jabcb wrote:The cylinders might be out of balance with the right cylinder producing most of the power & the left getting more oil than it needs.
So a general tuneup might solve this. Start with the points & plugs. And sync & adjust the carbs.

What is the bike's history?
I have about 50 miles on a total ground up restoration - crank seals and balance, connecting rods and bearings, piston, rings, oversize hone etc. I removed both baffles and both sound identically loud with equal smoke output. However, it does need a timing. Still can't account for the very different decibel output though. I will examine the baffles, and then proceed to timing her.
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