honda305 Home honda305 Auctions honda305 Gallery honda305 Forum


honda305.com Forum

Login
□ Search
□ FAQ 
□ 
Vintage Honda Owners,
Restorers, Riders and
Admirers

CB77 Muffler Disassembly for Restoration

advmaxx
honda305.com Member
Posts: 18
Joined: Wed Nov 16, 2011 10:49 pm

CB77 Muffler Disassembly for Restoration

Post by advmaxx » Sun Nov 20, 2011 2:44 am

Back when I restored my '62 CB77 I decided to use reproduction mufflers as they only cost $200 each and they looked just like the originals, but new. When I restored my '64 I think a set cost me about $500 or so, but the bike came with old, incorrect aftermarket mufflers, so I had to get 'em. Still not a bad price for a faithful, high-quality reproduction.

Now that I'm approaching the re-assembly portion of my '63 restoration, the only reproduction mufflers I can find domestically are $995 plus shipping. This is excessive. It's also why I'm taking another look at the original mufflers from the '62. I thought they were too far gone to re-chrome, but upon inspection I find they are solid. Although the chrome is toast, there isn't a ton of rust, mainly some greenish corrosion coming through from the copper plate. The left side muffler is perfectly straight, but the right side has some quarter-sized dings and scrapes in it, and it's a little flat on the bottom of the front end.

Along with some other parts, the mufflers are currently at the stripper (metal stripper, that is), and rather than just having them rechromed as-is, I'm considering cutting the weld on the one that is dinged-up to straighten it out. I have a fair amount of metalworking and welding experience, so I believe I have the skills to accomplish the task.

Does anyone have experience opening one of these up? If so, what is the best way to cut it? Just grind off the original weld? Sould I cut through the end rings, or cut them off? Should I drill out the front mount or cut that in half too? Do I need to strip the chrome off the weld areas before I re-weld?

Any info regarding this would be greatly appreciated.

Thanks.

User avatar
G-Man
honda305.com Member
Posts: 5678
Joined: Wed Mar 25, 2009 5:17 pm
Location: Derby, UK
Contact:

Post by G-Man » Sun Nov 20, 2011 6:00 am

I have a friend who has done this. He uses a file to remove the weld from the seams as it allows him to be more careful and only remove the minimum of metal. To part the seams he uses a very thin paint scraper pushed into the seam to avoid distortion. Once they are split the halves are very floppy so you need to hold them steady when working on them. Not sure what he does with the ring at the front end.

Once repaired and polished the two halves are carefully TIG welded together again.

There is a guy in the UK who is working on some very faithful stainless replicas using all original material thicknesses and dimensions to get the right sound.

G
'60 C77 '60 C72 '62 C72 Dream '63 CL72
'61 CB72 '64 CB77 '65 CB160
'66 Matchless 350 '67 CL77
'67 S90 '77 CB400F

User avatar
Snakeoil
honda305.com Member
Posts: 1150
Joined: Wed Aug 04, 2010 6:45 pm
Location: Upstate NY

Post by Snakeoil » Sun Nov 20, 2011 10:20 am

Maxx,

Who is replating your mufflers? Normally platers will not touch a set of mufflers because the carbon deposits polute their tanks. I assume this guy is taking care of that. I nave a muffler I need to replate for a CB160 and would appreciate the contact info.

Thanks and regards,
Rob

FAST FRED
honda305.com Member
Posts: 166
Joined: Tue Oct 14, 2008 10:30 pm
Location: SACRAMENTO, CA

HYDRO-SONIC

Post by FAST FRED » Sun Nov 20, 2011 5:20 pm

Rob, I had that happen to me, My plater was not sure He wanted to do My CL77 pipes and muffler. The Honda dealer I worked for had a huge Hydro Sonic cleaning tank to clean parts. The pipes had to be done half submerged as they were too long to fit in the tank. The cleaning process destroyed all traces of carbon and rust scale. Yes the carbon and crap stayed in the tank but the system ran a oil scimmer and filter. My plater agreed to plate the pipes after he inspected them.

Fast Fred
65 CL77
66 CL77
76 CB550FKR
76 CT90

advmaxx
honda305.com Member
Posts: 18
Joined: Wed Nov 16, 2011 10:49 pm

Post by advmaxx » Sun Nov 20, 2011 5:43 pm

Gman: Thanks for the reply/info. Using a file makes sense. I get the feeling the chrome plating needs to be removed from the weld area so as not to contaminate the weld. I'm in the US, so exchange rate and shipping would probably make the repros you mention prohibitively expensive, but perhaps you can post his info if he has something available. I know there's a guy in Austrailia making good stainless reproductions at $600AU. The price is reasonable as the exchange rate is about even but shipping would put it up towards the unreasonable, methinks.

Rob: I'm in SoCal, there's a ton of platers in my area, but I have the mufflers at a stripper's who said when I get 'em back they will be free of rust and carbon inside and out. Most platers would agree to plate them if they are clean, as Fast Fred mentioned. I send my important stuff to a guy in Seattle, though I haven't contacted him about the mufflers. He does a flawless job, although a bit expensive it's worth it. I will probably use a local guy for the mufflers, the important thing is to find someone who cares about what he's doing. Let me know if you still want the contact info.

User avatar
Snakeoil
honda305.com Member
Posts: 1150
Joined: Wed Aug 04, 2010 6:45 pm
Location: Upstate NY

Post by Snakeoil » Sun Nov 20, 2011 8:10 pm

Thanks, Maxx. I have a friend in the radiator busines and was going to ask him to hot tank the mufflers. I may investigate other options for cleaning them.

I'd be curious what you plater charges to do you mufflers.

regards,
Rob

advmaxx
honda305.com Member
Posts: 18
Joined: Wed Nov 16, 2011 10:49 pm

Post by advmaxx » Sun Nov 20, 2011 10:44 pm

Snakeoil wrote:I'd be curious what you plater charges to do you mufflers.
Yup, me too. I'll let you know what I find out. When I get the mufflers back from the stripper I'll get a quote locally and let you know. I'll have to call my Seattle guy to get an idea of what he wants to do the job. I'm going to put these on my '62, the bike I originally removed them from, so I want them done well.

If I go ahead with disassembly, I may post the project with photos and info.

Cheers.

Post Reply




 

CB-77 | CYP-77 | Road Test | Riding Log | Literature | Zen | Marketplace | VJ Survey | Links | Home