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Mufflers and Baffles

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Mgreen
Posts: 2
Joined: Sun Feb 14, 2021 2:14 pm

Mufflers and Baffles

Post by Mgreen »

Hi - I have a '65 R50 that I have owned for over 30 years. The bike has Ghost Motorcycle stickers, but the previous owner was from West Virginia. It came with aftermarket mufflers, that one of you might recognize from the photograph. I think they are funky period pieces and I'd like to keep them. The bike has a nice original/used patina.
muffler.jpg
Recently, I was trying to adjust the idle by ear by listening to the exhaust notes from the rear of the bike. I noticed the right side had a stronger exhaust pressure. However, when I disconnected the plug from the right cylinder, the right muffler still had a stronger exhaust pressure.

On closer examination, I realized the left muffler has a baffle about a foot from the exit, but this baffle is missing from the right side. So the exhaust from both cylinders is always taking the path of least resistance and going (mostly, say 70/30) out the right side.

Here's a muffler colonoscopy:
With the baffle:
rm.jpg
No baffle:
lm.jpg
I think I have three options:
1) Do nothing. It might have been this way for years. However, I'm worried about the imbalance of the cylinders because each side is behaving differently.
2) Remove the baffle so neither side has a baffle. At least then they would be equal and balanced. It's not too noisy on the side with no baffle, so there is some 'silencing' going on. I could try to hammer out the baffle or drill a large hole through it.
3) Buy stock mufflers and maybe pipes because it's all rusted together. New mufflers are around $700, half the original purchase price of the entire bike.

Mike Green
Riverside, RI

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schrader7032
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Location: San Antonio, TX
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Re: Mufflers and Baffles

Post by schrader7032 »

Welcome to the forum! You could balance the idle as well as the rest of the carb synch by doing a plug short. It consists of building a plug extension...old spoke material or threaded rod works well...and then you use a plastic handle screwdriver to short from the extension to the engine fins. The other cylinder will continue to run, or maybe only run for a couple of revolutions. Do the same shorting on the other side and see if the lone cylinder runs the same once the other is shorted. Then make adjustments. This same technique is use to balance the throttle cables.

I suppose one could just pull the plug and let the magneto safety gap take care of the ungrounded spark...provided the safety gap is adjusted correctly.

I'd say get the carbs adjusted the better way and then not worry about what's happening at the end of the muffler.
Kurt in S.A.
'78 R100/7 '69 R69S '52 R25/2
Fast. Neat. Average. Friendly. Good. Good.

Mgreen
Posts: 2
Joined: Sun Feb 14, 2021 2:14 pm

Re: Mufflers and Baffles

Post by Mgreen »

Thanks, I managed to adjust the carbs and the throttle cables, and the bike runs OK. I’m just wondering if I should be concerned about the asymmetric mufflers and the unbalanced combustion.

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Flx48
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Re: Mufflers and Baffles

Post by Flx48 »

Mike-
Sent you a pm.
Best-
George

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