ENGINE
For 2020 the reverse-slant 450 lump has had
some serious internal work. As before, the
engine is electric start. The cylinder head and
everything inside is new – and is 10mm lower
and 10mm narrower, as well as 305g lighter.
Cams, valves and valve-train is new, with the
valve angle being reduced by 7°. New intake
and exhaust ports have been reshaped
for increased airflow at mid-to-high valve
opening, and there are now two exhaust
studs rather than three.
Other changes include a new header
pipe with 3.2mm bigger diameter at the
connecting joint, updated ECU settings, a new
material for the air-filter and bigger dogs on
the gears to improve shifting from 2nd to 3rd,
and 3rd to 4th gears.
SUSPENSION
KYB units at both ends are similar to last
year’s bouncy bits, the front fork is a coil-
spring twin-chamber design. For 2020
Yamaha hasn’t messed with the well-
loved forks other than with changes to
The combustion chamber has had a volume the compression and rebound damping
reduction of 6.65cc, which has, in part, helped settings/circuits. There’s more progressive
increase the compression ratio from 12.8 to
compression damping during the mid-to-
13.0:1, and there’s a new piston design and
end stroke on the fork. The rear shock gets
a 1.5mm longer con-rod (for less rod angle
compression and rebound setting changes
during crank rotation, reducing piston friction too.
by a claimed 2%).
58 KIWI RIDER