Topic: CB750 K0 muffler design

[tlbranth]

Pretty soon I'll be having a go at building a new 4 into 4 exhaust system for my CB750 K0. This will include building the mufflers. I'd like to stick to the original sound as closely as possible. So If anyone (hondaman?) could fill me in on the original muffler design I'd be all ears. Thanks in advance for your help.

[PeWe]

Maybe a member has a rotten HM300 pipe that can be cut open?
The even earlier Lotus root pipes are more open with minimum of discs inside. Darker sound.

CB750 has its typical sound despite exhaust. I replaced my Lotus Root 4-4 pipes a few weeks ago, now Hindle 4-2-1, visited a friend on the countryside that heard that I was coming for a visit. He did not know that I have switched pipes.

[evinrude7]

https://www.ebay.com/itm/Honda-CB750-Exhaust-Baffles-Diffuser-CB-750-Baffle-18311-300-320-Set-of-4-HM300-/201687094880

[70CB750]

Cyclex has headers 4 to 4, just find mufflers. 

[JamesH_Sussex]

Pretty sure there is a thread on here somewhere?

[JamesH_Sussex]

Anatomy of a HM341
 https://r.tapatalk.com/shareLink?share_fid=13548&share_tid=131905&url=http%3A%2F%2Fforums%2Esohc4%2Enet%2Findex%2Ephp%3Ftopic%3D131905&share_type=t

Here’s one on the HM341...

[JDS]

I think the baffles has a large part to play in it. I've been told there is a difference in the sound of the 300 compared to a 341 and I believe the baffles were different. I just replaced a rather rusty set of 300s on my k1 with some much nicer 341s. The 300s are going into the scrap pile and if it would help you're more than welcome to the best one out of the bunch. Maybe a forensic autopsy would reveal something.

[754]

That would be where to start , he is in WA state.

[PeWe]

I think the baffles has a large part to play in it. I've been told there is a difference in the sound of the 300 compared to a 341 and I believe the baffles were different. I just replaced a rather rusty set of 300s on my k1 with some much nicer 341s. The 300s are going into the scrap pile and if it would help you're more than welcome to the best one out of the bunch. Maybe a forensic autopsy would reveal something.

Cut open autopsy of the HM300 and publish photos here would be perfect!

[kmb69]

I think the baffles has a large part to play in it. I've been told there is a difference in the sound of the 300 compared to a 341 and I believe the baffles were different. I just replaced a rather rusty set of 300s on my k1 with some much nicer 341s. The 300s are going into the scrap pile and if it would help you're more than welcome to the best one out of the bunch. Maybe a forensic autopsy would reveal something.

Baffles are way different. The baffle really doesn't do so much in the 341 pipes as they are heavily baffled internally.

[tlbranth]

That would be where to start , he is in WA state.

I'm not familiar with the nomenclature so I'm assuming 300's go on a K0. If so I would love to have one I could take apart. Would you please pm me with details? Thanks. I'd be happy to post pictures of the construction.

[ekpent]

300's were used on the 1971/K1 also. I think member Lordmorphy or something spelled like that was once making or having some luscious looking 4 to 4 CR style pipes made once.

[PeWe]

lordmoonpie    http://www.moonpie.co.uk/
Here an interesting thread about alternative 4-4
http://forums.sohc4.net/index.php/topic,61931.0.html

[ekpent]

 Lordy - Lordy -  lordy knew it was something like that PeWe    Good memory on you !

[PeWe]

That name is unusual..lordcreampie...hmmm lordmoonpie... I checked out his site about CR750 4-4 pipes a few years ago.