DIRTBIKE

THE BACK END | HERITAGE Compiled by: Warren Jack

THE HIGH PRICEOF STAYING AHEAD
With four minis to test and 11 junior riders on
board, this shootout must have been bigger than
Ben Hur. To make things more complicated,
Kawasaki had been dominating junior start lines
for three years but the results of this test weren’t
so clear cut. The other factories had all been busy
but the Kwaka was the most radically updated
of the bunch. Overall, Kawasaki was the choice
for expert riders due to its top-end delivery, with
Yamaha in second but Suzuki and Honda equal
third. For non-experts it was Yamaha, Suzuki,
Kawasaki and then Honda. The red machine was
cheapest at $1649 with spares kit, next was
the Kawasaki at $1699 with spares kit and race
preparation manual, $1725 for the Suzuki with
nothing and $1750 for the Yamaha with spares
and race manual.

ATTACK OF THE MUSCLEBOUND CYBERNAUT

KTM approached the problem of broadening

two-stroke power delivery from a different

angle to the Japanese factories. They were

using mechanical devices to alter port timing,

with names like YPVS, ATAC, AEC or KIPS,

but KTM used a digital ignition to advance

and retard the timing and spark duration to

match the revs and power curve. The exhaust

port had been lowered 1mm from the ’85

model to improve bottom-end and normally

that would have robbed power from up higher

but the new ignition smoothed things out

substantially. In fact, ADB claimed it as “the

smoothest power delivery you’ll ever feel” and

later in the test, “we figure this KTM comes

closer to challenging the Jap bikes on Aussie

turf than any European bike ever has since

the Jap stuff became popular”.

The KTM 250MX cost $4445 and had a

five-speed gearbox, 300mm of suspension

travel at both ends courtesy of a Marzocchi

fork and White Power shock. The kerb weight

was 96.75kg with no fuel in the 9.3 litre

petrol tank.

ISSUE #81

80 PAGES, $2.95

APR 1986

ON THECOVER

KTM’s new Digital Control Ignition on the 250MX launched Austria into the lead in the

“sensible stakes” for engine design. No complicated fricky, frackery here, fella! The

technology was expected to revolutionise dirtbike design.

156 | APRIL 2016 http://www.adbmag.com.au