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Discussion Starter #1
So my stock muffler is toast. There are a million leaks on the thing and it throws carbon everywhere on the bike, not to mention the smell it gets on my clothes, and I drag old bike smell everywhere I go ):

I like the look of straight pipes on these older bikes, but don't want to loose all that back pressure. My idea was to chop the muffler off and put a washer in there (for back pressure) then run straight pipes from there.

I realize there is added sound, I realize it will need to be tuned. That is not what this thread is about...I'm looking for advice on the back pressure here, will this be sufficient? Anyone have experience with this? Will I need to add washers in series or will one do the trick? Any other ideas are welcome I am still in the design stage of this and looking for ideas.
 

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What kind of machine are we talking about? Back pressure is necessary for decent running, but less so on older bikes that were tuned richer than more modern ones. You might need to re-jet, you might not. The shock wave that travels back up the exhaust can sometimes have a far more important effect on tuning....you would be better off fitting a half decent muffler or exhaust system rather than bastardizing it...do what you're talking about and your performance will probably suffer.
 

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Discussion Starter #3
What kind of machine are we talking about? Back pressure is necessary for decent running, but less so on older bikes that were tuned richer than more modern ones. You might need to re-jet, you might not. The shock wave that travels back up the exhaust can sometimes have a far more important effect on tuning....you would be better off fitting a half decent muffler or exhaust system rather than bastardizing it...do what you're talking about and your performance will probably suffer.
That is what I was afraid of! It is a 1972 Honda CL 175. Who sells mufflers? Would this just be a universal muffler?
 

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You don't need back pressure, anything over about 2psi in exhaust system is costing power.
What you do need is correct pipe diameter and length. (generally much smaller diameter than what 'looks good')
A parallel pipe will only give a power 'boost' over about 500 rpm range, if you get the length wrong (usually way too short) you will lose power everywhere.
Best example I've seen was a few years ago when 'everyone' was fitting drag pipes on Harley's.
883 Sportster went from 43bhp to 36bhp, even after jetting.
The motor just couldn't turn over fast enough to use the short pipes.
In my experience with Honda 175 twins, the long reverse cone megaphone works best, I haven't seen a 'good' pair for years though, the current generic will work though, get some listed for 500~750
 

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I don't know where you live, but you might want to check out the aftermarket offerings at Bikebandit.com The little reverse cone mufflers are inexpensive, inoffensive sounding and seem to work well on small Hondas...no need to fiddle with jet sizes.
1972 Honda Scrambler 175 CL175K6 Exhaust Accessories (Universal) - BikeBandit.com

Of course, if you have lots of money and are a stickler for authenticity, you could try David Silver Spares.
 

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If he just wants VW Taper Tips, all he has to do is go down to his local VW dealer, they probably still have them or can order them. They sold those things right out of a glass case in the car dealerships service department for half a century.
 

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or get a copy of VW Action, and go through the ads. Still a large following for aircooled bugs even if prices are now totally stupid for a rusty shell
 
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