with a old 2-stoke 250 motor, and a little work, maybe the p1-250 grid will grow next year :mrgreen:
PM sent. By the way, it’s a P2 chassis 
actually P1 
the frame is in fact a Yamaha factory race RD-56 , stamped on the frame ( verified by Denis C. )
they where made from 1963-66
Phil Read won the 1964 250cc world Championship on one, and our very own
Michelle Duff was his teammate, who finished 3rd!
Allan
#393
And where would a guy come across such a find. Fantastic.
little ole ladies basement :mrgreen:
p.s big thanks to Jim and Herb.B
Allan
#393
Very cool, that bike needs to be on the grid for 2013!
Allan
Very nice find indeed..lookinf forward to seeing it on the grid Allan…You try and get a hold of Brad Boomer on our site as Autofobe Allan he might have an old two stroker laying around…again you have the starts of something very nice..
Regards Paul
after a weeks crash course on Yamaha racing history, and talking with a ton of people, I knew I had to build something special. the original RD-56, housed a 250 rotary valve 2-stroke, and trying to build something similar I thought I would opt for a Kawasaki samurai 250 rotary valve. Period correct.makes some sence 
then Brad said something to me about a special that was built in 1967, the Z608. [attachment=1]36560569.gif[/attachment]
In 1967 yamaha built 6 prototype bikes to race in the Daytona 200, the bike used a rd-56 frame reworked to house a production YR-1 350 motor. well then, thats what I want to replicate.the new project is a P1-350 . lots of work to go , but the motor just slotted in like it was made for it
Hi Alan,
Love your RD56 roller and the YR-1 engine is great (I’ve owned a YR-1 for 43 years).
I began something similar a number or years ago - but ersatz, stuff built to resemble the Z608, not the real thing like yours, sold a lot of the bits off ages ago.
The only thing you might have trouble with re: period-correct tech, is the swing arm. I checked my Z608 files, went on line and checked a few of the photos posted there of the Z608 and the RD56 and didn’t see any rectangular-section swingarms in 1967 (maybe '68 - I didn’t check). I had already purchased a box swingarm for it but the tech decision was something like “not a chance”, so I went back to a YR-1 swingarm, which I think is a little longer than the RD56 swinger but might not fit in a “real” frame. The other biggy was “no TR2 engine parts” and I sent and received some spirited emails about using the 1969 YR-3 cylinders (YR-1, YR-2 and YR-3 were all basically the same motor but the '69 barrels were true 5 port cylinders).
Coolest project bike I’ve seen in some time.
Good luck on the build. I’ll be watching this 'un.
Regards,
Pat Cowan,
Vintage Motorcycle Fiberglass