“They were massive changes. Almost every week there were new
parts and things from the factory to trial,” he recalls.
“It was a neat experience, with Suzuki being the dominant force
in motocross as the time,” he says.
When this RN400 came to New Zealand, Burling picked up the
bike and got it running before spending the next few summers
travelling around the country with Colemans’ team.
The RN ruled the roost, but with suspension travel of just
165mm (6.5ins) front and 120mm (4.5ins) rear, it was overtaken
by the outstanding RM370 model and retired to the back of
the Coleman’s workshop. When Barry Senn got his hands on
the bike, many of the important components were still intact.
It’s not possible to wind back the clock, but for motorcyclists it is
still possible to go back and grab a handful of the machinery they
found exciting when they were younger – a genetic disposition
to reconnect with the bikes of their youth – and who can blame
Burling for choosing the RN? It is a true works bike from a time
when Suzuki led the motocross world.
REBUILDING A LEGEND
Burling got most of the parts when he bought the Suzuki –
certainly the important ones – although they were in a terrible
state. The alloy tank, seat, cast magnesium hubs, factory chrome
moly frame, airbox, sandcast magnesium crankcases, crankshaft,
gears, magnesium clutch basket and the clutch plates. The
carefully-milled front brake and clutch levers, as well as the billetmachined
gear and rear brake levers, and the rear brake torque
arm were all intact. They’re works of art, and highlight Suzuki’s noholds-barred
attitude to its works machines.
The handlebars have been replaced by modern lightweight
versions, with a bend as close to the originals as possible. The
search is still on for an original set, but they were higher and
wider back then, and no modern bars have been found close
to that configuration.
The 82mm bore x 75mm stroke cylinder, standard piston
and head are new originals, and the VM36SCC (36mm) Keihin
carburettor was also there. Burling suspects the unharmed
expansion chamber was probably the last original Suzuki one left
in the world. The lightweight chambers were always vulnerable
beneath the engine, and had to be replaced every race or two.
With the RM series came a high-pipe over the top of the engine,
and while this configuration drastically reduced damage to the
pipe, it changed the nature of the bike.
“The RN’s full-flow pipe makes a big difference to the
horsepower. It wasn’t the best solution for off-road use, but it
made good power. It’s also why the engine sounds different,
because the pipe is so much longer in the chamber section,”
says Burling.
36 KIWI RIDER