1973 Yamaha RD350 - 4-Page Vintage Motorcycle Road Test Article

Description

1973 Yamaha RD350 - 4-Page Vintage Motorcycle Road Test Article
Original, vintage magazine article
Page Size: Approx. 8" x 11" (21 cm x 28 cm) each page
Condition: Good
THE NEW YAMAHA RD 350
might well be termed the brother of
the giant killer if it were compared
to its stablemate, the TR3. Racing
versions of the RD 350 have suc-
cessfully trounced machines over
twice their size in AMA Class C
competition for the past several
years with such regularity that you
know it couldn’t be a mistake.
Many features of the new RD
350 have come as a direct result of Yamaha’s participation in
road racing, both in the United States and abroad, proving that
there is truth in the adage “racing improves the breed.”
The RD 350 is a cafe racer’s delight with its slim, sleek
styling, disc brake on the front wheel and a closely-spaced
six-speed transmission. It also appeals to the daily commuter
who rides his motorcycle back and forth to work. Its light
weight and nimble handling characteristics make it an ideal
vehicle for combating the traffic jams found in so many of
today’s cities.
Or take the RD 350 out on a favorite stretch of hilly,
winding road where the six-speed transmission and powerful
front disc brake can be used to their fullest and you’ll find a
race-bred motorcycle in a street machine’s clothing.
Here is where we find out what a motorcycle can do.
Accelerate rapidly to a certain speed, decelerate by use of the
brakes, swoop through a series of turns at a good angle of lean
without dragging the side or center stand. This is where the
RD 350 excels.
High speed turns exhibited the bike’s near neutral handling
characteristics with little tendency to oversteer when the
power was applied. It had no tendency to plow or turn in on
itself in slow turns. It felt as though the Yamaha was on rails,
the rear wheel faithfully following the line taken by the front
wheel. These are the same fine characteristics we found on the
R5 that we tested a couple of years ago.
Aside from the reed valve induction system and the
six-speed transmission the RD 350 is almost a carbon copy of
last year’s R5D. The narrow crankshaft assembly is supported
by four hefty ball bearings and a labyrinth seal separates the
two crank chambers. Roller bearings support the connecting
rods at the bottom and needle bearings are employed at the
small ends to carry the two-ring pistons.
Like most Japanese two-stroke Twins, the RD 350 requires
several kicks with the choke full on to get it running and then
a minute or so warm-up before setting off on a ride. Snick the
short-throw gear lever down into first gear, release the clutch
and you’re off on a ride that closely approximates the ride on
a road racing machine.
Even though the new transmission has six speeds, first and
sixth gears provide almost the same reductions as did the older
first and fifth gears. The RD 350 pulls well from about 3500
rpm to 8000 rpm which makes it seem unnecessary to have an
extra gear. But the joy obtained from riding an RD 350 with
its closely spaced gears is worth the extra trouble Yamaha
went to. Shift lever throw is short and positive and the
gearbox is very quiet in operation.
Of special interest is the reed valve induction system, called
Torque Induction by Yamaha. In this system an additional
seventh port is present and is really just an upward extension
of the inlet port. The reed valve unit is located in the original
inlet tract and opens as long as there is a demand for a fresh
fuel/air charge, hence there is less chance of fuel being wasted
by too great a throttle opening in relation to the engine’s rpm
or from blow-back through the carburetor because of too low ...
12661-7302-08 mb2128-74RTA-08