Author Topic: "Period correct" 4 into 2 exhausts  (Read 519 times)

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Offline zabzob

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"Period correct" 4 into 2 exhausts
« on: January 14, 2022, 01:55:36 PM »
I am thinking going for collector plate status for my 1975 CB750K. There are stipulations about the condition of the bike and any aftermarket parts/upgrades. Some upgrades are allowed as long as they are "period correct," which means available within 2 years plus or minus of the original manufacture date. I have Mac 4 into 2 exhaust, which is not vintage... but I'm wondering if that was an available aftermarket option at the time the bike was built?

Anybody have info on that?
1975 CB750K5

Offline BenelliSEI

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Re: "Period correct" 4 into 2 exhausts
« Reply #1 on: January 14, 2022, 02:18:47 PM »
My bet is you would find them available in 1976-77. Try searching vintage Mac ads?

Offline HondaMan

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Re: "Period correct" 4 into 2 exhausts
« Reply #2 on: January 14, 2022, 02:42:51 PM »
In '75 there were:
Hooker headers
Mac headers, 4-1 nd 4-2
Yoshimura headers
Jardine (4-2) headers
Kerker headers (4-1 only)
TT pipes from many vendors (usually chopper parts hawkers) with really poor chrome
See SOHC4shop@gmail.com for info about the gadgets I make for these bikes.

The demons are repulsed when a man does good. Use that.
Blood is thicker than water, but motor oil is thicker yet...so, don't mess with my SOHC4, or I might have to hurt you.
Hondaman's creed: "Bikers are family. Treat them accordingly."

Link to Hondaman Ignition: http://forums.sohc4.net/index.php?topic=67543.0

Link to My CB750 Book: https://www.lulu.com/search?adult_audience_rating=00&page=1&pageSize=10&q=my+cb750+book

Link to website: www.SOHC4shop.com

Offline zabzob

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Re: "Period correct" 4 into 2 exhausts
« Reply #3 on: January 14, 2022, 03:43:57 PM »
Mac 4 into 2 headers are period correct, perfect, thanks!
1975 CB750K5

Offline ekpent

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Re: "Period correct" 4 into 2 exhausts
« Reply #4 on: January 15, 2022, 06:42:28 AM »
 Have owned many 750's that came to me with the original head pipes where the rotted mufflers were cut off and what must of been the very popular slip on mufflers installed.

Offline HondaMan

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Re: "Period correct" 4 into 2 exhausts
« Reply #5 on: January 15, 2022, 07:49:01 AM »
Have owned many 750's that came to me with the original head pipes where the rotted mufflers were cut off and what must of been the very popular slip on mufflers installed.

Jardine was the most common one of those I saw. I have 2 sets of them (rusted together!) hanging in the shed.
See SOHC4shop@gmail.com for info about the gadgets I make for these bikes.

The demons are repulsed when a man does good. Use that.
Blood is thicker than water, but motor oil is thicker yet...so, don't mess with my SOHC4, or I might have to hurt you.
Hondaman's creed: "Bikers are family. Treat them accordingly."

Link to Hondaman Ignition: http://forums.sohc4.net/index.php?topic=67543.0

Link to My CB750 Book: https://www.lulu.com/search?adult_audience_rating=00&page=1&pageSize=10&q=my+cb750+book

Link to website: www.SOHC4shop.com

Offline ekpent

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Re: "Period correct" 4 into 2 exhausts
« Reply #6 on: January 15, 2022, 08:35:30 AM »
 Yep - the classic old turn outs. I had some on a RC836 engine and when the cheap MAC 4-1 first hit the scene bought one and put on the bike. Ended up unhappy with a big flat spot so went back to the good old stock head pipes and slip on turn-outs. I kind of like having a pipe/muffler on both sides of the bike.  8)