Topic: Yoshimura Exhaust, CB400F - How Rare???

[Terry in Australia]

Looks suspiciously like a homemade job to me! The back end / silencer looks suspiciously like a Piper exhaust with homemade header pipes welded on ,then the whole lot painted black!

The exhaust is superbly fabricated and the bends fashioned expertly.  The welds are extremely neat. 

Yeah, but it's still fcuking ugly..............

[robnobrakes]

Beauty is in the eye of the beholder

[harisuluv]

Interesting.  After reading through the whole thread it seems that it is somewhat up in the air as the identity of the exhaust.  The OP seems to be convinced it is genuine though.  I feel like OP really WANTS it to be real, already come to the conclusion that he wants and is now trying to fill in the rest.  Could be real or not, but I would try to look at things objectively and try to have practical expectations.

[robnobrakes]

Interesting.  After reading through the whole thread it seems that it is somewhat up in the air as the identity of the exhaust.  The OP seems to be convinced it is genuine though.  I feel like OP really WANTS it to be real, already come to the conclusion that he wants and is now trying to fill in the rest.  Could be real or not, but I would try to look at things objectively and try to have practical expectations.

[/quote]
Yoshi or not, it's a nice looking bit of kit weighing in at 3.4Kg.  I am advised on another forum that the stock system weighs 6.8Kg.
[/quote]
I am interested but not bothered one way or the other as to the true identity of the exhaust, but it is a bit of a mystery.  The seller of the bike said it was a Yoshi, so I assumed it was.  My original question was is it rare?  The answer seems to be yes, whoever fabricated the exhaust

[Cundalini]

Bike would a lot better though with the original exhaust system on though! Being that it appears to be in such excellent condition! But as a complete exhaust from D. Silver is about £70,000,000,000  now you are probably right to stick with this one!

[vfourfreak]

I bought a system exactly the same as that one (but in chrome) for my 400f in 1977. I got it from Dixon Racing in the UK, who were the Yoshimura agents at the time. It was marketed as a Yoshi pipe, but had no Yoshi plate or stampings. I recall having to file the flanges on two of the headers to get them to fit into the exhaust ports, so the engineering standard was not 100%. The main benefits I got from the pipe was weight loss and better ground clearance on the right.
Kev

[Retro Rocket]

To me it sounds like Dixon Racing may have used the Yoshi name to market the pipe, interesting....

[vfourfreak]

To me it sounds like Dixon Racing may have used the Yoshi name to market the pipe, interesting....

You could be quite correct there mate !
Kev

[Gregorymoto]

My chime in about the BS has nothing to do with the pipe. It has to do with people saying not to cafe the bike. It's his bike. He should do what ever he wants.
P.S. I love M3 racing more than i love my mom

[Retro Rocket]

P.S. I love M3 racing more than i love my mom

 

[robnobrakes]

I bought a system exactly the same as that one (but in chrome) for my 400f in 1977. I got it from Dixon Racing in the UK, who were the Yoshimura agents at the time. It was marketed as a Yoshi pipe, but had no Yoshi plate or stampings. I recall having to file the flanges on two of the headers to get them to fit into the exhaust ports, so the engineering standard was not 100%. The main benefits I got from the pipe was weight loss and better ground clearance on the right.
Kev

The plot thickens

I also found this

http://www.davidsilverspares.co.uk/stock/Classicbike_April_2012_web.pdf

trolling through www.  Page 40 of the article shows a photo of a red Mocheck Harrier CB400/4.  The article states the bike has a Yoshimura 460cc kit, piper cam and piper exhaust.  The exhaust looks identical to the one fitted on my 400/4.

[Terry in Australia]

"Trolling", or "Trawling"? Ha ha, anyway, yep, I reckon you're right mate, I vaguely remember Piper exhausts, and from memory, they weren't bad quality. I love those rims, are they the same as your new ones? I've got them on my CB750 and think they look very "Period Cool" Cheers, Terry.

[robnobrakes]

I love those rims, are they the same as your new ones? I've got them on my CB750 and think they look very "Period Cool" Cheers, Terry.

Close up of my flanged rim

[Terry in Australia]

Sweet!

[Tim2005]

I bought a system exactly the same as that one (but in chrome) for my 400f in 1977. I got it from Dixon Racing in the UK, who were the Yoshimura agents at the time. It was marketed as a Yoshi pipe, but had no Yoshi plate or stampings. I recall having to file the flanges on two of the headers to get them to fit into the exhaust ports, so the engineering standard was not 100%. The main benefits I got from the pipe was weight loss and better ground clearance on the right.
Kev

The plot thickens

I also found this

http://www.davidsilverspares.co.uk/stock/Classicbike_April_2012_web.pdf

trolling through www.  Page 40 of the article shows a photo of a red Mocheck Harrier CB400/4.  The article states the bike has a Yoshimura 460cc kit, piper cam and piper exhaust.  The exhaust looks identical to the one fitted on my 400/4.

That article is a bit misleading, it shows a pic of the Mocheck race bike then a description of the Mocheck Harrier road bike (race had wire wheels, road had CMA alloys). This is a Harrier
http://www.flickriver.com/photos/chris531/2949751790/   , there's a few of them around the shows etc & a nice replica of one appeared last year too.

Here's a pic of the 400/4 Piper exhaust too.

Kev is right about Dixon Racing, they were down in Surrey and supplied all the 750 Yoshi stuff too.

[robnobrakes]

Your photo settles it.  It's not a Piper exhaust, which in the photo does not look very well fabricated imo.  However, my exhaust looks identical to the one fitted to the red bike

Any more ideas

[malcolmgb]

It's a possibility Piper made a version for the road and track, the road version would allow access to the filter the track not.

[Terry in Australia]

Yep, I reckon you're right Malcolm, the straight pipe from the collector back doesn't look like anything Yoshimura would have done.

Same for the showy "curly" headers, Yoshimura were all about performance, and while those "spaghetti" headers might have been all about "equal length" attributes, Yoshimura would have just run equal length headers down the centre with it's trademark "S" shaped big bore pipe from the collector back, with their usual "oil filter removal access and centre stand be damned!" attitude. Cheers, Terry.

[Gregorymoto]

I hate that TV show. It gives everyone who sees me on my bike the right to ask me if I watch it. I don't, I don't even have a TV. I built my cb750F 22 years ago, hell I'm still building it.

The current Cafe interest, I think, may be American thing, not least helped by the Cafe Racer TV series's.  It's been popular in the UK since the 1950's, and Japanese riders have been into the classic Brit bikes for ages.

Yoshi or not, it's a nice looking bit of kit weighing in at 3.4Kg.  I am advised on another forum that the stock system weighs 6.8Kg.
[/quote]

[tom400f]

I think the exhaust is a Yoshimura of its time, here's a picture of one from ebay a while ago.

I used to have one. Can't remember where I bought it so I can't comment on the confusion with the similar looking Piper but mine had the same sticker.

As a youngster I just bunged it on the bike and increased the mains to the next size up. Ran fine.

[Terry in Australia]

That's it, I reckon we should hold a seance and channel Pops and ask him. Anyone here psychic?

[malcolmgb]

That's it, I reckon we should hold a seance and channel Pops and ask him. Anyone here psychic?

There are some that could be classed psychotic would that help. 

[Terry in Australia]

That's it, I reckon we should hold a seance and channel Pops and ask him. Anyone here psychic?

There are some that could be classed psychotic would that help. 

Ha ha, yep, we've got our fair share of them mate!

[D-Rider]

Hi Everyone - Newbie here.

I have a 1976 CB400F that I bought when it was just one year old.
Lovely bike but sadly I let it languish in the garage for many years while the kids were growing up and I had other things occupying too much time. That doesn't mean I was without bikes all that time but the 400/4 has been off the road for far too long.
Anyway, I've always planned to get it back on the road and have been picking up bits and pieces for a while.

I digress ... that exhaust .... yes it IS a Yoshimura (part number YH-3-35). I have one on my bike - I bought it from Dixon Racing in the late 1970s. They were available in either black or chrome (though mine is a rather natty chrome/rust finish  ).
From the 1982 Dixon Racing catalogue it seems that for a while, Yoshimura had an exhaust production facility in UK - something I've only just discovered (though have no other detail of this).
I have links to pdfs of these catalogues but for some reason the forum tells me I'm not allowed to post external links .... not sure how to share this info with you .....

That exhaust is a work of art and the sound it makes when pushing towards the red line is a real howl (recently found a Youtube clip of one of these - I had planned to give the link but again it seems that I cannot submit external links in a post ..... )

I've been wondering whether I can get my Yoshi pipe restored or perhaps used as a pattern for someone to make a stainless copy.
I think the chances of actually finding a decent one up for sale are less than slim so it'll be a case of whether I can get mine restored or a copy made economically - or ditching the idea and going for one of the other options out there.

Anyway - Hi everyone 

[Retro Rocket]

I have links to pdfs of these catalogues but for some reason the forum tells me I'm not allowed to post external links

You need a minimum of 5 posts before posting links, spam filter...    Post away...