1973 Works Yamaha YZ250
The bike featured here is a "works" 1973 Yamaha YZ250.  This bike was raced by
Haken Andersson in the 1973 250GP World Championship. At the first race held in
Barcelona, Spain, Haken finished 6th in the first moto and 2nd in the next moto. The
second race was held in Serramazzoni, Italy. Haken finished third in the first moto
and sixth in the second moto. It was at the third race of the season held in
Wuustwezel, Belgium that Haken showed up on Yamaha's "monoshock" works bike.
He ultimately won the 1973 250GP World Championship!

The works motors for 1973 used an all new crank case design made from sand cast
magnesium and featured a new style clutch actuating arm that went through the top
of the cases. The front and rear wheels are sand cast magnesium as is upper triple
clamp.  The lower clamp is machined aluminum and the fasteners are titanium. The
fuel tank is a hand formed aluminum high capacity tank.  The rear "thermal flow"
shocks, still under development, were sand cast in magnesium. The front forks are
hand made except for the sliders which are cast aluminum. The fork legs are knurled
where they make contact with the triple clamps. Most of the fasteners used are
titanium.
Double click
Double Click
The top triple clamp is sand cast magnesium and the bottom, machined aluminum.  The forks are machined between
the top and lower triple clams and knurled at the lower clamp for better grip.
The "Thermal Flow" rear shocks were still under development. The lower bodies were sand cast in magnesium.
The 1973 works YZ featured the new style clutch actuating arm. It improved the pull and feel of the clutch.
This bike was shipped to the United States from Sweden where it was eventually restored.  It was fairly complete but
in rough condition.
The high capacity aluminum fuel tank was hammered and required a great deal of work to restore.
A lot of time and effort went into restoring this bike as the pictures so.