HELP! need crank overhaul for obscure Japanese vintage bike

Egiffis

New Member
Hey guys,

i have a 1968 Yamaha YR1, commonly named the grand dad to the RD series..
i need to do a bottom end rebuild and i can't find a NOS replacement crank so i guess the only solution is to get the stock one reworked. i can't find any shop willing to do so, and the only one i can find wants more then i paid for the bike. i know this baby is obscure but I'm sure there must be other options then a 4 figure crank overhaul?

any leads to people willing to take on projects?

thanks.
 
What does 'reworked' mean? For general wear and tear I expect you need new bearings and the rod ends cleaned up. Or are you looking to have it balanced etc?
 
http://kenoconnorracing.com/ He is highly regarded and likes oddball stuff.East coast location.
 
Thanks for chiming in guys.
Im in Los Angeles.
I tried Ken Oconnor, his response was as follows.
"I don't have the fixtures to assemble that crankshaft."

the plot thickens.
 
Rod kits will be around $90.00 each if you can find something to fit, may ave to look through catalogues and match up with a later motor?
Main bearings, if Yamaha specials and not 'off the shelf items, will be around $50.00+ each
Crank seals shouldn't be too expensive but add around another $40.00 just to be safe.
Labour on top of all that will probably be a couple of hundred.
Not having fitting to do it is a polite way of saying ' take it somewhere else'
You need no 'special tools' to rebuild twin cylinder cranks, the hardest part is making sure the phasing is correct (180 or 360 degree's on a twin)
Triple's are a bit more difficult but not too bad.
All you really need is a 20 ton press, some press plates and mandrels plus a bunch of patience (oh, a few big lead hammers help ;) )
If I didn't already have way too many projects on the go I would do it for you (mailing to Florida shouldn't be more than $40.00 :D )
Single cyl cranks are so simple I could teach people to recondition them in a couple of days when I was an instructor 8)
 
Hey CrazyPJ,

i greatly appreciate the response, it makes me feel much better. i will start doing some research and try and find some other shops- this bike will get back to tip top shape!
 
You will probably find it easier to get done if you already have all the parts.
The hunting things down is time consuming.
You need to know center to center length plus the width of big and small ends. May find a modern Yam MX/trailhas same sizes?
 
hey CrazyPJ,

another great tip, thank you. i prob won't rip into this bottom end for another 2-3 weeks but when i do that, ill be sure to check cross over ability.

thanks again!
 
I think the crank halves are splined like RD cranks, and the YR1 is different design completely to the YDS3 etc 250 twin IIRC. Those were vertically split and the 350 (R1, 3 etc) was really the start of the RD line. Bore and stroke were 61 x 59.6 so the rods may be an issue, but as PJ mentioned may be available from one of the singles.
 
Hey Teazer! thanks for the insight- all thoughts are super appreciated. i will keep that in mind when i tear down.
 
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