OzVMX Forum

Clubroom => General Discussion => Topic started by: Nathan S on May 20, 2009, 12:20:47 pm

Title: Yamaha YDS MX bikes?
Post by: Nathan S on May 20, 2009, 12:20:47 pm: I've seen a pic of a YDS1 being used in the All Japan MX series, back in the 60s - but I can't find the pic or any details on the web.

Does anyone know anything about such a beast?
I can't imagine them being any good when compared to a big pommy single or a twin-pipe CZ, but its got me wondering...

What are the differences between a YDS1 and 7?
I've read a lot of contradicatory stuff, but even so, the only real changes that I've read about are auto-lube in 63 or 64, and horizontally split cases in the late 60s.
Title: Re: Yamaha YDS MX bikes?
Post by: vandy010 on May 20, 2009, 12:49:45 pm: http://cgi.ebay.com.au/Yamaha-YDS-305-CC-Collectable-late-60s_W0QQitemZ150345477458QQcmdZViewItemQQptZAU_Motorcycles?hash=item150345477458&_trksid=p3286.c0.m14&_trkparms=66%3A2%7C65%3A1%7C39%3A1%7C240%3A1318%7C301%3A1%7C293%3A1%7C294%3A50

they don't seem to be as early a model as i'd hoped. i like em, but they look like they'd slot into pre~70 in which case, i'll stick with my RT1.
other than that, i don't know much.
Title: Re: Yamaha YDS MX bikes?
Post by: firko on May 20, 2009, 01:36:05 pm: Fumio Ito raced his YD 250 to 6th place in the 1958 Catalia GP. It was Yamahas first international race and 6th wasn't too shabby.
(http://img.villagephotos.com/p/2005-8/1062154/Catalina%20GP%20Fumio%20Ito.jpg)
Title: Re: Yamaha YDS MX bikes?
Post by: mx250 on May 20, 2009, 01:49:57 pm: (http://i323.photobucket.com/albums/nn458/mx250syd/d803.jpg) Front wheel off the ground and powering on ;D.

Yeah, a great result for first up and a rider not familiar with the terrain/track.
Title: Re: Yamaha YDS MX bikes?
Post by: mx250 on May 20, 2009, 02:22:17 pm: Quote from: Nathan S on May 20, 2009, 12:20:47 pm
What are the differences between a YDS1 and 7?
I've read a lot of contradicatory stuff, but even so, the only real changes that I've read about are auto-lube in 63 or 64, and horizontally split cases in the late 60s.

Like chalk and cheese.

YDS1-3 similar with crank mounted clutch, but many differences as developed. All vertically split cases.

(http://i323.photobucket.com/albums/nn458/mx250syd/n_1a.jpg)(http://i323.photobucket.com/albums/nn458/mx250syd/me2.jpg)

YDS5 and 6 a development of 1-3 but with normal clutch +++.

250 YDS series and 350 YR1 series used different engines.

(http://i323.photobucket.com/albums/nn458/mx250syd/yam-yds5e-6.jpg)(http://i323.photobucket.com/albums/nn458/mx250syd/3296_3.jpg)

The YDS's were heavy and overengineered. I would suspect they would be limited in their adaption to scambles. Were used with success in Yankee oval/1/2 mile racing.

(http://i323.photobucket.com/albums/nn458/mx250syd/YamAscotScrambler1963.jpg)

The Suzuki super six might be a better option. (This is not a super six ;))

(http://i323.photobucket.com/albums/nn458/mx250syd/15493479-15928-large.jpg)

DS7, like chalk and cheese. A complete new genre with virtually nothing carrying over. Become horizontal split cases and the basis of the RD series that kept the same architecture through to the RZ. DS7 and YR5 shared same engines as did all RD/TZ 250/350's with changes to bore only.

(http://i323.photobucket.com/albums/nn458/mx250syd/DS7_72.gif)
Title: Re: Yamaha YDS MX bikes?
Post by: mx250 on May 22, 2009, 08:54:17 pm: There you go Nat, you can motocross the YDS. Hows this for serious air? :D

(http://i323.photobucket.com/albums/nn458/mx250syd/jump1.jpg)
Title: Re: Yamaha YDS MX bikes?
Post by: mainline on May 22, 2009, 10:12:05 pm: old mate doesn't look overly confident about the landing
Title: Re: Yamaha YDS MX bikes?
Post by: albrid-3 on May 22, 2009, 10:34:26 pm: thats is my barrel on the tm twin port
Title: Re: Yamaha YDS MX bikes?
Post by: firko on May 23, 2009, 11:17:01 am: (http://img.villagephotos.com/p/2005-8/1062154/YamAscotScrambler1963.jpg)
How cool is that DS3 Yammy. I had the exact same model and colour back in the early '70s. My first roady! I'll post a piccy when I find it.