OzVMX Forum
Marque Remarks => Yamaha => Topic started by: Nathan S on March 20, 2008, 10:29:27 pm
-
Anyone got any info and/or pics, particularly on the 1977 version?
I'm poured over mxworksbike.com (76 version) and the article on the 77 version in VMX, and seen the photo in Yamaha Dirtbikes (78 version), but still have some unanswered questions.
I'm seriously thinking of building a replica of the 77 model - largely because it'd be an interesting way of using left-over parts, and partly to test my (limited) fabrication skills.
Thoughts/advice/abuse?
Edit: Unless I can find a Shinobi head, my replica will be air cooled. And t will simply run a plastic D/E fuel tank, rather than the OW's splinky alloy one.
-
Go for it ;D
-
YZ125J radiator, YZ125G forks machined down, The waterpump could be placed where the old oil injector pump was(maybe a waterpump housing from an '86 YZ125 could be addapted). Billet triples. The rear brake pedal would be hard to repliacate unless you can find a kickstart shaft long enough to get the brake pedal on.
I think a YZ125D/E airbox and then of course you or someone will have to make that ali OW tank.
It will be great to see you build this bike.
-
DJR, apparently great minds think alike - and apparently your's and mine do too... :D
Here's what I'm thinking:
C frame, with E down-tube and engine cradle.
F swing arm.
Custom rear shock, based on a C reservoir, but with 46mm piston and guts from something else (125E?).
E tank.
D guards.
Not sure about seat yet.
250E forks & triples.
250H front TLS front brake.
F rear brake backing plate.
Custom full floating rear brake torque arm.
C front hub.
D rear wheel.
I'm not sure about what to do with the engine. The OW barrel has six fins, same as an MX125A. If I start with a set of C cases, the MX barrel goes straight on, but the drama is that the C cases don't accept the D/E magneto cover, as fitted to the '77 OW.
So maybe the answer is to use D/E cases and magneto cover, with an E barrel, and an A cylinder head?
Ideally I'd find a sensibly priced Shinobi head and use a H/J radiator, but...
I'm not overly worried about the rear brake pedal - I might be overly optimistic, but I reckon that a little bit of machining on both the clutch cover and then back of the kick-starter will give me enough room for the pedal - the side loads can be supported by the clutch cover and kick-starter rather than the shaft itself.
Blue means I don't have those bits yet.
-
Hey mate, Sounds like a great idea!
I am encounting a few porblems trying to make my 73 ra125 suzuki works bike,
I want a rm125a motor in it but the clutch case on the ra has the clutch arm going down sort of when the rm's is on the top ! :(
-
I have some surplus F bits, haven't had a good look at the condition of the swingarm, but it might need some tidying up.
-
Is this what you want Nat?
(http://i96.photobucket.com/albums/l187/mx250a/07vetworlds007.jpg)
Go here...
http://www.vitalmx.com/photos/features/2007-White-Bros-World-Vet-Championship,2487/Terry-Goods-OW27,9031/GuyB,64
...to get a blow up.
-
Actually, wouldn't you want an earlier steel swingarm?
-
If you have some tig welding skills and a reasonably handy with panel beaters hammers you could possibly cut down a larger 250/400 C or X model tank to get that squared off rear look and you could easily make the transluscent sidecovers from a transluscent 20 litre plastic drum. I've just used the same method to make the front number plate for my trials bike.
(http://img.villagephotos.com/p/2005-8/1062154/yamahaow272.jpg)
(http://img.villagephotos.com/p/2005-8/1062154/yamahaow27.jpg)
(http://img.villagephotos.com/p/2005-8/1062154/yamahaow271.jpg)
The bike I've posted is very different to the Terry Good bike. What's the go there? It's supposed to be an OW27.
-
i don't know about you blokes, but i've always been confused by the numbers yamaha use.
the OW bit is easy=works
numbers? blowed if i know, 27-36-49 take your pic
nice bike though.
-
FIRKO YOU SHOULD CONTACT SCOTT AT CONCORSE PARTS (VMXPLASTIC), HE MAKES TRANSLUSCENT FRONT NUMBER PLATE KITS, SAME AS A MX/YZ PLATE EXCEPT TRANSLUSCENT, I RUN ONE ON THE COOPER MX, A TOP PRODUCT.
-
Firko, is that a genuine works bike or was it a works bike with a few missing parts that couldnt be replaced so the owner has had to compromise with other parts from newer YZ's? Although I assume the OW's were always bikes in progression/modification. It is still a very cool looking bike.
I love the swingarm on that bike.
The numbers of the works bikes did seem strange but then if you add in the roadracing OW works bikes the numbering might be less confusing.
-
Nathan - have articles on OW27 from Cycle and Popular Cycling magazines. Happy to Scan them for you. Have attatched a low quality scan from popular cycle test. Note it has a steel swingarm interestingly MXA August 1977 shows OW27 with alloy swing arm!
-
MXA August 1977
-
DJ....I don't know anything about the bike I posted other than it being represented as an OW27. The exhaust runs on the different side to the Terry Good bike, it has an alloy swingarm and the mudguards are different. Below is the description given with the photo. It seems that there are more than one OW27 and they are very different. Another moto mystery to solve!
"1977 Yamaha OW 27, same bike as Bob Hannah raced in America, this one has the water cooled kit which they took away at the beginning of the season due to a claiming rule of that year. CNC machined billet aluminum triple clamp. Magnesium hubs. Extremely light, tons of titanium, hand-pounded aluminum tank, sand-cast water pump case, Only one known to exist."
Betric.....I've got a DG replica transluscent front number plate from Magoo on my Maico but for the trials bike it's just a square panel which can't be bought and is easy to make from old shit plastic drum I had laying around. What are you bringing to CD5 Dave?
-
Firko/DJ, could it be Glover's bike?
-
The VMX article said that the OW27 ran up until 1980, but it was continually evolving over the years.
In order of age:
Terry Good's ex-Hannah bike;
The one in mposs' article;
Gerard Rond's one in VMX;
the one in Firko's pics.
I'm aiming for something around the 77 Hannah bike and the 77 Rond bike.
-
Nathan the bike I posted is supposed to be a '77 model as well and it's very different to the Tery Goode bike which is different to the Rond bike. Could the factory have had so much variation in the one year?? I suspect the bike I posted may be a '78 model. Works bikes were always evolving and if I were building a replica I'd find the common denomiators like the tanks and side covers and possibly the frame and build the rest using whatever looked closest as you eluded to doing in an earlier post. Works bikes were never an exact science anyway so bit of chop and change won't detract from what you're aiming at.
-
Firko I am bringing to CD5 the road registed Cooper, the bling MX Cooper, a full set of XR75 4 speed models (K0 to K3) and a nice unrestored 1973 MX80 for show and tell, plus a XR75 K4 pit bike and the RM250D to ride, should also have on show a very nice 76 XT500 with less than 3000km on it, a 78 CR250R and some other bikes???
-
The Terry Goode bike represents a 1976 OW27, the one that Hannah beat Marty Smith on for the 76 125 series-even has the #39 on it. So...after seeing the pics in 77 MXA too, that would be more representative of an OW27 raced in 77. You are on the right track for sure. A period aftermarket swingarm made to look like the works unit would be better, JMO.
James
-
Nathan, its going to be a case of mix and match(just like the factories did in the day). I was on the understanding that "the Hurricane" got the euro '75 model OW for the '76 winter series until the infamous claiming rule scared the shit out of yamaha and they shipped the bike away.
Anyway, with all the variations of the OW27, it will be in your favour when you build the bike.