Topic: 1971 K0 CB500

[Little_Phil]

nice bikes little phil!

Same bike. Dressed for riding on the right and dressed for riding on the left. 

[Shtonecb500]

The paint job is gone! I'm glad Sean wanted it and rescue it. Probably wouldn't have ended up stripping the paint off of it the longer I looked at it - but i may have gotten the urge to try because its the original.

Is spraying something like WD-40 in the drain exhaust holes a good idea to help dispel lingering water?

I have this fear and dread that the pipes will start to crumble after being in use for a month lol.

Still need a left side 1971 fork ear if anyone has one in good condition, I cant find any online.

Figured I can use the seat strap off my cb500 seat on my blue bike since that is getting a new saddle anyway.

If I can find a great patina paint job I may go that route since the frame is going to maintain an overall weathered look anyway.

[grcamna2]

The exhaust need highway riding to get them hot enough and blow-out that acid water;short trips are what rot out exhausts.

[Shtonecb500]

Brackets that the rear flashers are on don't look standard.

look, its on this 750 too.

[Shtonecb500]

Getting paint done at Daves Customs off of 8 mile.


Blah, it would be nice to have body work done and back in a month.

[grcamna2]

Paint work is getting done by Daves Customs around 8 mile and Middlebelt and Dr. Ru is going to do the pinstripe, no decal on this one....100%paint. - Probably going to cost 600-800.

Funny how life works, I had an unpleasant encounter with someone yesterday, today I would need a favor where someone would have to ask that negative encounter person to do something for me, lol.

So I almost just feel like waiting the 2 weeks until Phil gets back in town and I can get into the shop with no favors needed.


blah.

Lol !    I feel you.

[grcamna2]

The inside looks real good,did you clean it with something ?

[Shtonecb500]

The inside looks real good,did you clean it with something ?

thats how it was when i bought the bike 5 years ago and thats how it is today lol. Ive just always had gas in it.

[Shtonecb500]

i didnt know original 500 tank strip came in pieces and you can still order them, currently unavailable but still...

I think I destroyed a couple in the last few yers not knowing any better.

[Shtonecb500]

I found a bike for sale in Ohio that has the body kit i need, oem. fml.

[Shtonecb500]

Found some rot under pipe #4, highly disappointed I missed this. I bought this bike thinking the pipes had no holes, I would have passed on it.




After looking at it some more, I imagine that entire area covered in surface rust is ready to rot through...even though it felt solid on the other side.

how did i miss that, lol?

[Alan F.]

That sucks, sorry to hear.

[Shtonecb500]

That sucks, sorry to hear.

I found some promising exhaust repair threads on here, one yielding some great results, I imagine after I cut out the section, fabricated the replacement, i could have a local shop tig it. Meanwhile, I'll be on the look out for a #4 pipe.

[Alan F.]

There seems to be a good amount of 500 pipes on ebay, searching #4 comes up empty, they're all labeled left or right upper & lower....

[seanbarney41]

What I have found, looking for nice original used 500/550 hm323 pipes.  Lower pipes either side are plentiful and reasonably priced.  Upper pipes that are nice enough to warrant an ebay purchase and shipping are extremely scarce.  Last 550 I owned had 3 out of 4 pipes perfect with a lh upper totally  and completely rotted out.  I lucked out and found one a little worse condition than what you are showing there, Shtone.  A friend of mine brazed silicon bronze with a TiG to repair about 3 holes and I had to patch the end cap of the baffle as it had been drilled.  If I remember correctly, #4 is rh upper?   So you would have a tough time finding a nice replacement for a reasonable price.  More likely to find a whole set for crazy money as I was offered by several members here after posting a want ad.

[Shtonecb500]

There seems to be a good amount of 500 pipes on ebay, searching #4 comes up empty, they're all labeled left or right upper & lower....

Yep, there are a few on there but all the wrong one. There is one floating round but has scratches on the bulbous portion. I'm leaning heavily towards cutting out the rot and fixing it...might as well fix it instead of it leaving my possession with infection.

[Shtonecb500]

What I have found, looking for nice original used 500/550 hm323 pipes.  Lower pipes either side are plentiful and reasonably priced.  Upper pipes that are nice enough to warrant an ebay purchase and shipping are extremely scarce.  Last 550 I owned had 3 out of 4 pipes perfect with a lh upper totally  and completely rotted out.  I lucked out and found one a little worse condition than what you are showing there, Shtone.  A friend of mine brazed silicon bronze with a TiG to repair about 3 holes and I had to patch the end cap of the baffle as it had been drilled.  If I remember correctly, #4 is rh upper?   So you would have a tough time finding a nice replacement for a reasonable price.  More likely to find a whole set for crazy money as I was offered by several members here after posting a want ad.

oof, I mean tig weld. Ya, seems impossible to find this pipe in good shape, I'm thinking more and more that im lucky that the rot is underneath and hasn't yet wrapped around to the front of the pipe, if anything...this is a fantastic candidate for repair...if I can keep burn marks from spreading to the front of the pipe.

[wolf550]

man that is the same pipe that I had started to see about making aluminum replica replacement mufflers that you could cut the original from the pipe and refit the aluminum cast to it. kinda like the jardine mufflers to their exaust pipes.

[grcamna2]

There seems to be a good amount of 500 pipes on ebay, searching #4 comes up empty, they're all labeled left or right upper & lower....

yep, there are a few on there but all the wrong one. There is one floating round but has scratches on the bulbous portion. Im leaning heavily towards cutting out the rot and fixing it....i might as well fix it instead of it leaving my possession with infection.

Oh yeah  ,
I've added patches over holes in stock exhausts before;I prep the area,use some good sheet metal(sometimes galvanized)and a #1 tip on my torch set with some braze.I like that the patch you install will be out of the line of sight on your exhaust because those are nice looking pipes 

[Shtonecb500]

 the pics from this post I found
http://forums.sohc4.net/index.php?topic=115427.0

[grcamna2]

Im guessing tig spot weld, then braze the rest closed?

I don't know how to electric weld,just braze.I like your idea of 'tig spotting' it.
I like the way Tig looks  but not sure if it will blast through thin metal.

[Shtonecb500]

It’s not as bad as I thought it was, not sure what to do here…thought the rot was further along.
The areas are very firm still so its still a good candidate for splice and weld . The the side of the seam with the drain hole is firm with no give and maybe could just use some paint sort of treatment so slow it down....otherwise any welding in that area is going to leave burn marks on the chrome portion we can see. What If I cut open the bad side and while its open I paint the inside where the rust is with some rustoleum..or can we not paint the inside of the pipe?

The other option is let the next owner deal with it? It seems solid enough to let a new owner handle it - I still don't want to drop 800 bucks for a new paint job unless someone can convince me otherwise.

option 1: polish and clean pipes, no repair, find survivor body kit ($300-400), top end rebuild, tune up, sell.
option 2: repair pipe, polish all pipes,, $800 for new paint, top end rebuild, tune up, sell.
option 3: put on a donor tank and random covers (cheapest options), top end rebuild, tune up, no repair on pipe.

of course, disclose the pipe on every option.

My thinking is after the top end rebuild and polish the pipes i should be able to recoup my initial investment of 3k even without repairing that pipe.

[SOHC4 Cafe Racer Fan]

I'd try to stop the rust, polish the pipes but not invest in a reproduction set (they're available but very pricey through David Silver Spares).

[Shtonecb500]

.

[grcamna2]

You peeled back the outer cover over the inner special 'tuned header' tube which needs to be sealed inside.
They designed the inner exhaust header 'tube' to fit inside the outer chrome section(engineers designed that inner 'tube'/pipe for the exact flow to match the performance of the bike's needs)as the outer section protects the inner part from getting dinged(imo)and changing the flow of the exhaust.
I would peel back a little more of the outer section and seal the inside 'tube' before covering it all back over;otherwise the same acid exhaust water will rust through the inner header 'tube' and create a bigger rust hole all the way through.