Yoshimura R&D Superbike

Well, after a year of thinking, researching, and finding parts, I figure I ought to start a build thread...

It all started with this picture:


I wound up starting a research thread , trying to find more information on that bike. As it turns out, that particular motorcycle was a scale model that took a good chunk of time to create.

I wound up finding this brochure on here - this is what I need to build my project:

So where do I stand today you ask???

Well, thanks to this great forum, I've sourced all of my parts as well as a project bike from members here.

Z1B basketcase- Kawiboy514
29mm smoothbore carbs- dutchz
Yosh slipper pistons- zrxrich
Yosh Series 1 4-1 exhaust- mark1122
Yosh Series 2 4-1 exhaust- porchev914
Z1R wheels- Mark Wing


Lately, I've been looking for motorcycle-related ways to make a bit of extra cash that I can use on this project. I have a few sets of VM28 carburetors that I'm meticulously rebuilding, the first set is ready to sell, here's the link ! Grab them while they're hot!

Here's the basketcase '75 that I'm starting with. I kind of like the tank, might keep it

MMS_0442 by mmsmithgall , on Flickr

MMS_0480 by mmsmithgall , on Flickr

MMS_0470 by mmsmithgall , on Flickr

MMS_0441 by mmsmithgall , on Flickr

MMS_0436 by mmsmithgall , on Flickr

MMS_0423 by mmsmithgall , on Flickr

Here are the set of 29mm smoothbores I bought from dutchz. From what we know, they were likely "ported & polished" by Pops Yoshimura back in the 70s because the carburetor mouths are blended in to the velocity stacks and there's a small metallic Yoshimura sticker on the #1 carb float bowl.

MMS_0332 by mmsmithgall , on Flickr

MMS_0337 by mmsmithgall , on Flickr

MMS_0342 by mmsmithgall , on Flickr

MMS_0345 by mmsmithgall , on Flickr

MMS_0357 by mmsmithgall , on Flickr

MMS_0369 by mmsmithgall , on Flickr

I was lucky enough to track down a set of brand new Yoshimura Stage IV 1015cc slipper pistons.

MMS_0377 by mmsmithgall , on Flickr

MMS_0401 by mmsmithgall , on Flickr

MMS_0409 by mmsmithgall , on Flickr

MMS_0413 by mmsmithgall , on Flickr

MMS_0414 by mmsmithgall , on Flickr

MMS_0421 by mmsmithgall , on Flickr

MMS_0392 by mmsmithgall , on Flickr

MMS_0394 by mmsmithgall , on Flickr

MMS_0407 by mmsmithgall , on Flickr

MMS_0382 by mmsmithgall , on Flickr

MMS_0386 by mmsmithgall , on Flickr

MMS_0396 by mmsmithgall , on Flickr

Now for the exhaust... the original Yosh AMA superbike had a modified 4-4 Z1 exhaust system. There's a place in Japan that remanufactures that exhaust system for a very hefty price of $3,500 USD.


For the time being, I'll just run a Yoshimura 4-1 system. A few months ago, I bought a Series I pipe, but that's at my parent's house in Pennsylvania at the moment - I'm waiting to bite the bullet to ship it cross-country. This past weekend, I scored a Series 2 pipe from porschev914. A dyno test waaay down the line will determine which system I use. :evil:

MMS_0909 by mmsmithgall , on Flickr

MMS_0915 by mmsmithgall , on Flickr

MMS_0906 by mmsmithgall , on Flickr

MMS_0899 by mmsmithgall , on Flickr

MMS_0900 by mmsmithgall , on Flickr

MMS_0903 by mmsmithgall , on Flickr

MMS_0893 by mmsmithgall , on Flickr

This really cool, great Idea to build one up. Really good job sourcing the parts, amazing the stuff was around. Keep up the good work, and keep posting pictures.

Looking forward to watching your build Mark.
Have fun.

I can't wait to see some progress on this project.
I know where you can get it painted.
Mark

Wow, what a build. I'd be willing to bet that there are still a few sets of pistons stashed away in some of the team mechanics stashes.
You really went deep into the research and digging up of bona fied parts. The 4-4 would be over the top. Good job. Can't wait to see this one completed.

Yosh cams and valve springs/retainers can still be had, all it takes is (lots of) money!

Yosh Stuff

WOW...this is a cool build. please let use follow the build with plenty of pics....very intresting build and I would venture to say historic a-bit.....yes