P92
FEATURE I PROTON KR3
(Left) Roberts
made the leap
from champion to
team manager to
constructor. This is the
body mock-up for his
first GP bike. (Below)
Technical director
Warren Willing was
hands-on throughout
the KR project. He
eventually left the
project at the behest
of Roberts to help turn
the Suzuki RGV500
into a race winner for
son Kenny Jr.
and achieved three eighth
places (Junior got two).
The Mk1 Modenas had
an over-riding flaw, explains
Team Roberts stalwart Tom
O'Kane, nowadays heading
Suzuki's MotoGP test team.
"It was a very clever bike,
but some ideas were ahead
of their time."
One original feature of the
two-down/one-up V3 en-
gine was that two adjacent
cylinders shared a common
crankcase volume, with one
down-cylinder piston rising
and falling in synch with its
adjacent up cylinder, and no
main-bearing between them.
"We used to call it 'a flying
web', because the middle
crank web was unsupport-
ed, with a crank-pin on each
side of it [disposed at the
angle of the V].
"It was an ambitious de-
sign, and there were certain
issues with cylinder filling,
with two carbs feeding into
the same crankcase volume."
Another unconventional
feature was the under-seat
radiator, fed by an air duct
beneath the fuel tank.
There were more ill-
advised adventures, O'Kane
continued. "That first bike
had standpipe carburetors,
which were also custom
made." These replace the
usual float-bowl/needle
valve with a weir system.
"With Yamaha, we'd been
having float-chamber prob-
lems when we pressurized
the airbox." The special
