Honda-SOHC
SOHC.co.uk Forums => Other Bikes => Topic started by: Otis on November 20, 2025, 02:18:16 PM
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Im certain this has been debated many many times but I happened to be a Kawasaki Dealership recently and did a double take.
In front of me was a brand spanking new 2025 Z900 with Four pipes. For a good few minutes I was just staggered at what I thought was an original 1970's legend until it dawned on me that this was a new bike. The Salesman informed me that the Four pipes were an optional extra for £2K and Kawasaki cannot believe how this bike has been received.
I am very old school and believe that there should be a pipe for every cylinder for no other reason than balance and aesthetics. (Ha,ha I know someone will bring up the triples but hey ho). Through the 70's; 80's; 90;'s and to date I have never seen any attraction for going multi cylinder into one pipe. I completely accept that beauty is in the eye of the beholder but I would love to receive comments from the enthusiast's for reducing pipes.
Happy and safe riding.
Cheers
Graham
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I agree, back in the 70's only reason for replacing with 4 into1 or 2 was cost
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I always thought a 4 into 1 silencer was to improve the exhaust extraction due to the back pressure in the exhaust system.
On cars a replacement manifold for the standard cast ones was a nice curvy manifold that paired the right cylinders together for maximum extraction into the rear silencer.
On tuned ADO 15 Minis BL special tunings answer was the long center branch manifold with a Y piece pipe at the bottom as it was cheaper than a decent Mangoletsi super curvy system, other considerations included chassis/body clearance.
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I always thought a 4 into 1 silencer was to improve the exhaust extraction due to the back pressure in the exhaust system.
On cars a replacement manifold for the standard cast ones was a nice curvy manifold that paired the right cylinders together for maximum extraction into the rear silencer.
On tuned ADO 15 Minis BL special tunings answer was the long center branch manifold with a Y piece pipe at the bottom as it was cheaper than a decent Mangoletsi super curvy system, other considerations included chassis/body clearance.
A few years ago I bought a Z1000 fitted with a 4 into 1 Harris by the previous owner, now this was probably due to cost but I thought it looked and sounded amazing , the neighbours were less than enthusiastic but I’ll let you make up your own mind please see video I made when selling it on.
Please forgive the heavy breathing in the sound track!
https://youtu.be/JYC-xFpoFAg
I still am in contact with the current owner and he has now fitted an original exhaust at great expense
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I always thought a 4 into 1 silencer was to improve the exhaust extraction due to the back pressure in the exhaust system.
On cars a replacement manifold for the standard cast ones was a nice curvy manifold that paired the right cylinders together for maximum extraction into the rear silencer.
On tuned ADO 15 Minis BL special tunings answer was the long center branch manifold with a Y piece pipe at the bottom as it was cheaper than a decent Mangoletsi super curvy system, other considerations included chassis/body clearance.
A few years ago I bought a Z1000 fitted with a 4 into 1 Harris by the previous owner, now this was probably due to cost but I thought it looked and sounded amazing , the neighbours were less than enthusiastic but I’ll let you make up your own mind please see video I made when selling it on.
Please forgive the heavy breathing in the sound track!
https://youtu.be/JYC-xFpoFAg
I still am in contact with the current owner and he has now fitted an original exhaust at great expense
Quite the most stunningly lovely bike and the sound is amazing but just think what it would have looked and sounded like with 4 pipes?
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I agree with you about the aesthetics when it comes to a 4 into 4 and how such pipes suit the Z900, 350/4, 750/4 etc but Honda did pull a masterstroke when it came to the 400/4. The 4-1 suits the bike perfectly especially with the sinuous lines taken by the header pipes to clear the oil filter. I thought Honda couldn't have got the 400/4 any better but of course they did, they painted it yellow but naturally, I may be slightly biased 😉.
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Beautiful bike,
I sort of think that the very short minimalist exhaust can suit that bike, which I think comes down from the great looking Moriwaki racers.
They do look fantastic with the original exhaust of course.
Ok so that’s me sat on the fence then 😂
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Thinking back to the 70's, my 1972 CB750 cost in the region of £750. After approx 14 or 15 months of short journeys I had 4 chrome pepperpots. Honda would not stretch their warranty to cover a replacement set, but wanted about £100 instead. At that time, Dave Degens (Dresda) had just marketed a 4 into 1 system so my mate duly took me there in the trusted mini van to collect. I remember looking inside the 'silencer' and being able to see all the way through. MAGIC!!! It fitted reasonably easily, and the sound, well! Up to about 4000rpm it growled like an early MGB, above that and it absolutely howled. Such Joy. The 4 pipes were bunched tight together right in front of the filter bolt, so, you change the oil when the engine is hot, right? Yes, but you had to remove the hot exhaust system to do it. Good game. Attached (hopefully) is the only pic. I have of it with this system, loaded up ready to depart the IOM 1973 TT.
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Nice photo, thanks for posting it.
I'd forgotten all about the 1970s air horn era!
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Nice photo, thanks for posting it.
I'd forgotten all about the 1970s air horn era!
Oh Dear, yes, aesthetics didn't really play a part in those days, neither did common sense. Those red monstrosities were electric horns and I just wired them in using the existing connections without a relay!!! The horn button only lasted a few months. Every day was a school day. Nowadays, the same level of 'audible approach' is obtained from a neat pair of small horns which sit just nicely under the nose of the tank.
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Was that a Degans made exhaust Mick or did he sell them for somebody else?
My S&S Rickman Honda CR750 exhaust is a 4-1 and just like the Dresda system when I looked through the pipe called a 'silencer' I could see straight through it (just as I can with the Jota silencers). It was ear splittingly LOUD!
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Was that a Degans made exhaust Mick or did he sell them for somebody else?
My S&S Rickman Honda CR750 exhaust is a 4-1 and just like the Dresda system when I looked through the pipe called a 'silencer' I could see straight through it (just as I can with the Jota silencers). It was ear splittingly LOUD!
Bleedin' 'ell Dave, that was just over 50 years ago, and a lot of beer has passed since then!! Couldn't tell you who made it, I was happy enough to be able to brag that "I've got a Dresda exhaust on mine". I found it was a bit Jekyll & Hyde, whereby up to about 4000 ish RPM it growled quite acceptably, but once it got to breathing properly. Oh yes it was bloody loud. Didn't worry too much, as by that time you were not hanging about, so it was mostly open road stuff. Have to admit though, that on the occasional Saturday night, 2nd gear got a few work outs round the Romford inner ring road, using the station bridge as the start line. Local plod only had blue and white Minors as panda cars. Sold it to get married, followed by my darling new wife saying that we really need another 750, the CD175 stop-gap being unacceptable. If the crappy photo uploads, it shows the result of a major spend:- New wife, new house, new matching Lewis Leathers kit, and a new 750, complete with No. 1 registration. GME 1N. (and 4 pipes !!). John Collier's really was the window to watch in Romford for posing!!!
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Surely the cylinders only go bang one at a time so three out of the four pipes are idle at any one moment ;D
I have always had a 4-1 on my bike, less clutter, lighter, cheaper, lovely sound, what's not to like ;D
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My K1 got a 4-1 system because it was supposed to increase performance, the 4 pipes were only refitted when I sold the bike.
However it also had something (a lot) to do with the sound, eventually a Dunstall 4-1 was fitted and it sounded glorious, my girlfriend had the kettle on way before I got to the house as she could hear the bike from miles away.
Cheers
Dennis
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Surely the cylinders only go bang one at a time so three out of the four pipes are idle at any one moment ;D
I have always had a 4-1 on my bike, less clutter, lighter, cheaper, lovely sound, what's not to like ;D
I agree about the less clutter, lighter, comment. The sounds of 4 pipes or 4 into 1 are both good, but definitely different. You pays your money, you takes your choice. Some of the earlier 4 into 2 systems had numbers 1 & 2 siamesed, and 3 & 4 siamesed. This meant that for each of those pairs you were actually putting a 2 into 1 system on a 180 degree firing arrangement, giving uneven breathing, and a not so smooth exhaust pulse/note. I remember there used to be a guy named Mick Hand who sprinted a C72 engined supercharged special, bloody quick as well. I tried to sell him an old CB77 engine I had, but he told me that because of the uneven firing pulses of the 180 crank, the supercharging would not work. If you look at all the twins with that crank arrangement, you will see that they have twin carbs for the same reason. So, a 4 into 1 system must have 1 & 4 joined along with 2 & 3, or all 4 joining together at the same point for a smooth flow, and the correct back pressures.
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If the crappy photo uploads, it shows the result of a major spend:- New wife, new house, new matching Lewis Leathers kit, and a new 750, complete with No. 1 registration. GME 1N. (and 4 pipes !!). John Collier's really was the window to watch in Romford for posing!!!
Wonderful memories. I can't believe the Moderator hasn't had something to say about the haircuts ;D ;D ;D
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I did think about it, but it would be a case of bricks and glasshouses as we all had hair like that in the 70s.
Well I did anyway.
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Was that a Degans made exhaust Mick or did he sell them for somebody else?
My S&S Rickman Honda CR750 exhaust is a 4-1 and just like the Dresda system when I looked through the pipe called a 'silencer' I could see straight through it (just as I can with the Jota silencers). It was ear splittingly LOUD!
Bleedin' 'ell Dave, that was just over 50 years ago, and a lot of beer has passed since then!! Couldn't tell you who made it, I was happy enough to be able to brag that "I've got a Dresda exhaust on mine". I found it was a bit Jekyll & Hyde, whereby up to about 4000 ish RPM it growled quite acceptably, but once it got to breathing properly. Oh yes it was bloody loud. Didn't worry too much, as by that time you were not hanging about, so it was mostly open road stuff. Have to admit though, that on the occasional Saturday night, 2nd gear got a few work outs round the Romford inner ring road, using the station bridge as the start line. Local plod only had blue and white Minors as panda cars. Sold it to get married, followed by my darling new wife saying that we really need another 750, the CD175 stop-gap being unacceptable. If the crappy photo uploads, it shows the result of a major spend:- New wife, new house, new matching Lewis Leathers kit, and a new 750, complete with No. 1 registration. GME 1N. (and 4 pipes !!). John Collier's really was the window to watch in Romford for posing!!!
Ahh, John Collier's (and THAT tag line) now there is a name from the past along with Burtons, Lord John and the still going Moss Bros. There was a saying that you bought a suit in Burtons for one of two reasons, 1. You were getting married (oh yes, that was me the first time round) or 2. You were due a court apperance (not me!).