Topic: yoshi exhaust restoration

[Shtonecb500]

Hey all,

I got this set up from dolomite for the sweet cost of free.

Ill take any advice on the restoration process and having it done professionally.

Also, does anyone know if these headers come out of the collector or if they are permanently in place?

I sprayed it with some oil and used a small torch but I just cant tell if they are stuck or not supposed to come out.
It doesn't look like there is removable baffle either, what should I expect...worst case best case scenario.

I plan on getting is blasted and ceramic coated.

PICTURES BELOW DONT CLICK ON THESE

[Bankerdanny]

I don't know what file format that is, but it won't open in any of the photo programs I have.

[754]

Not sure what you mean and can't open your pics.
 If there is a weld bead, it is not coming apart. For it to come apart it needs a slip joint  ie no weld where one pipe enters another
 If it's pitted, can't do much about that. So  blast it paint or coat it, use it.

[Tim2005]

I can't open that file type either. Though I'd be cautious about getting old exhausts blasted, the metal tends to be even thinner than it looks. Can you chemically strip the paint instead?  I assume we're talking paint here, as most Yoshi's weren't plated

[Bodi]

The .heic file format is an Apple form of h.265 image compression. As is usual for the weasels running Apple, this obscuration is to keep the Apple sheep in their little protected pasture and make it more confusing  should one wake up and try the world of real computers and phones. [/rant]
It is pretty simple to convert them to .jpg so here they are. Also, they were saved at quite high resolution - I resized to 1024x768 so I could upload rather than link them.

On topic: I'm not convinced this is a real Yoshimura exhaust. I've seen several and all have been welded up. This looks like an old Taiwanese exhaust type that was pretty common from a lot of places in the 70s with two main "features": crappy chrome plating and a vulnerability to quick rust-out if the bike was kept outside.
I can easily be wrong: I didn't see every Yoshi exhaust system and never bought one for any bike model. But that really strongly reminds me of imported crap I saw a lot of in the 70s.

[gschuld]

The header pipes on this exhaust are meant to be removable from the collector.  The brackets meant for bolts to clamp it together.  Rust is keeping them on currently.

Yoshimura made a bunch of versions of the cb750 exhaust, from
the early hand bent(gradual bent) race pipes to the more street type machine bent pipes with baffles.

I don’t recall ever seeing a ch750 Yoshi pipe with that removable header pipes design. Every one was welded at the collector to make a one piece pipe.

IMHO, it very likely not a Yoshimura pipe.

George

[seanbarney41]

But this is for 500/550, correct?  It was already confirmed as Yoshimura in another thread.  Maybe Shtone can link that one?

[Scott S]

http://forums.sohc4.net/index.php/topic,182899.0.html

[Shtonecb500]

Hey everyone,

Sorry for the formatting mishap, thanks for reformatting them and posting them for everyone to see. If i airdrop my pictures to my laptop they reformat for some reason...on my phone they are jpeg.  I ended up using a big boy torch and all the headers came right out with no problem .There isn't too information on vintage yoshi pipes online from basic searches. I used to think ALL vintage yoshi pipes were hand bent headers but I was wrong about that. I guess the repos all do something to cut corners, the new ones have welded muffler ends instead of that wonderfully swooping one piece. Maybe these are vintage repops and they cut the corners on the headers, idk.

I decided not to get it done professionally because it was going to cost me at least 300 bucks. So I'm doing the restoration myself.
I'll do some rough sanding to get as much of the pitting out then paint this and run it on a weird build or something...It has a small baffle in end of the pipe but that's it. Now that the collector is off and I can see down into the end of the pipe, IM wondering what's stopping me from shoving some muffler packing in there, any objections?

I carved the hole out clean, welded in a plug, made myself another hole in the process, then decided to braze the #$%* out of it at the end. Here are some more pictures.

[Shtonecb500]

But this is for 500/550, correct?  It was already confirmed as Yoshimura in another thread.  Maybe Shtone can link that one?

I was told it was a real pipe, I have no reason to doubt Dolomite but im aware there were a lot of fakes being made. I like to believe I got myself a gem lol.

[Shtonecb500]

But this is for 500/550, correct?  It was already confirmed as Yoshimura in another thread.  Maybe Shtone can link that one?

No, this is not for a 550, I wish I had a yoshi pipe  for my 550.

I did just see a 550 listed on eBay with an original set of 750 4into4 attached to it, all it needed was some rear supports made up. I wonder if I could fit this to a 550.

[754]

750 pipes dont fit onn500 or 550.
 If you did get them on mufflers would be at a ridiculous angle and look wrong.
 You have an old tired set of pipes, clean them up , use them and have fun..

[seanbarney41]

Pops Yoshimura started out as just a race bike tuner in the 1960's in Japan.  By 1970 or so, he had achieved enough success that Japanese race teams were paying him to solve problems that they could not.  The hand bent Yoshimura 4 into 1 was one of the first parts that Yoshimura company offered for sale to the public at large.  It was hand made by him or one of a few close associates, was meant for race only, and not many made it to the states.  This is why it is so rare today.  Only the first generation is all this true of.  Your pipe was made much later, after Yoshimura company had achieved more commercial success and was probably, designed or approved by Pops, developed by team, and then manufactured.

If you are interested in more history, member gshuld has a large collection of original catalogues and brochures.  He may be able to provide more accurate information on your pipe.

[seanbarney41]

This is the thread I was alluding to earlier, not the link Scott S. posted...


forums.sohc4.net/index.php/topic,181492.msg2104406.html#msg2104406

[Shtonecb500]

750 pipes dont fit onn500 or 550.
 If you did get them on mufflers would be at a ridiculous angle and look wrong.
 You have an old tired set of pipes, clean them up , use them and have fun..

haha yeah I've never tried but i saw this the other day, this is what i was referring to

[754]

Geez I thought I replied, not sure how they did it ? Maybe made angled spigot   ?

[Shtonecb500]

Pipe is up, not final but repaired and one round of sandblasting.

[DaveBarbier]

Regarding the iPhone picture formats, unsure if this was talked about previously but you can change in settings what format the camera shoots in. Settings>Camera>Formats> check Most Compatible.

[evinrude7]

Pipe is up, not final but repaired and one round of sandblasting.

looks cool.

[Shtonecb500]

Pipe is up, not final but repaired and one round of sandblasting.

looks cool.

yeah i like the pipe, if i sell the bike ill remove it and sell it with another exhaust set up.