THE INHALATION
Norrie states that the fuel and air mixture was
drawn into the crank via a Dell’Orto rather than
the usual choice of an Amal (popular amongst
the racers of that time) using a 150 main jet.
He says that the Dell’Orto items were fairly easy
to use and was originally a 28mm, but ended
up being a 30mm without an air filter. This was
attached to a short hand-made inlet manifold
which changed the position and location of the
carburettor, necessitating the need for a cut-
away section in the engine sidepanel moulding.
This had the benefit of a good position for plenty
of air intake in comparison to the standard
placement, with the added benefit of better and
easier access to the carburettor.
Crankcases from a Primavera were used and
the gearbox was a standard four-speed setup,
utilising straight cut primary gears. The power
produced was transmitted to the back wheel via
a Polini three-plate clutch setup and bell housing.
THE EXHALATION
The exhaust is an area of witchcraft I’ve never
been able to get my head round. Two-strokes
are all about gas flow; get the fuel and air in
and the combusted gasses out as smoothly and
quickly as possible and in theory you’ll have the
potential to increase power and therefore speed.
So you’d think that having a big cone-shaped
exhaust would be the best option? Not true!
You have to get your head round back
pressures, pulse waves plus a whole load of
maths and physics, as well as do a deal with
the devil. It really is a black art and all of which
seem extremely complicated, even by today’s
standards, with computerised models and the
like. So can you imagine the headaches back
in the early 1980s with all the trial and error?
Norrie eventually cobbled together an exhaust
that would fit and work very well. He used an old
Lambretta Fresco that was lying around which
he cut up and tacked together before sending it
off to be welded up perfectly (as Norrie states
he’s no welder). This was good for 10 or 11
thousand revs, but would crack, so he eventually
developed his own, the NFK.
THE ELECTRICS
The spark to ignite the fuel is generated by a
modified Lumenition ignition system through a
Krober high-power high tension coil. The scooter
runs on what’s known as a dead loss system,
meaning that it requires a battery to create the
power which generates the spark.
There is no means or requirement to put
power back into the battery, so when the
battery is flat the scooter is unable to generate
its own power to run. Norrie says that the
battery would be changed for a fully charged
one after each race, in preparation for the next.
The battery would also power the rev counter
and water pump.THE HANDLING & STOPPING
As a Vespa 90 Super Sprint, the handling was
always going to be great, but to improve further
over standard, a steel rod has been perfectly
shaped and welded along the outer edge of
the legshield where the traditional beading
would go, extending along the full length of the
floorboards.
This stiffens up the chassis considerably,
giving a much firmer feel.
The suspension is the standard setup, but
Norrie says the viscosity of the oil was changed
to stiffen things up. Surprisingly, the brakes are
the standard drum items front and rear. As an
ex-employee of Douglas, Norrie had managed to
get his hands on a pile of brake shoes which he
then subbed-out to a company who relined them
with different grades of friction surfaces. These
were made in pink, blue and yellow to clearly
differentiate between the different compound
grades; after much testing Norrie found the pink
type to be his preferred option and which suited
his particular riding style.THE COOLING
Cooling for the specially adapted cylinder head
begins with the front-positioned radiator; this is
then connected via quality plumbing to the water
pump, around the head and back to the radiator,
where the effect of the forced air cools the
liquid and the whole cycle continues.Very simple in design, with the pump
being an item fitted to a caravan, it’s very
inexpensive and readily available. Norrie did
use a Mercedes air conditioning pump, but this
proved to be an expensive item to replace.
Norrie states that the engine and cooling
system requires warming-up for approximately
10 minutes before the start of a race with the
water getting up to maximum temperature and
exchanged within the system several times.THE LOOKS
Along with the mechanicals of a race machine,
it should also look the business and the ‘Green
Meanie’ sure does look the part. Norrie took his
inspiration from the Kawasaki race machine of
seven times TT champion, Mick Grant, who he
has got to know over the years. The paintwork
was taken care of by Dream Machine of Long
Eaton, and what a job they did; it absolutely
gleams still to this day and the scheme still
doesn’t look dated.
The main sponsor was obviously Norrie’s
own business at the time, Midland Scooter
Centre, which is now owned by Andrew, the
son of Norrie’s ex-business partner, the late
Dave Webster. There’s an old Scootz sticker on
the tail section of the racing seat which Norrie
fabricated from a motorcycle item, then got
the parts company Lintek to produce. Scootz
was the business that Norrie’s son, Rob, had
prior to the setting-up of VE UK. The NFK on
the headlight blank is Norrie’s initials and the
“Look after it” is a friendly warning to Norrie’s
very good friend, ex-race team member and the
present custodian of the scooter, Mark Green.
So there we have it, the lowdown on a very
special Vespa Super Sprint racing scooter and
I for one have very much enjoyed being able
to have access to closely examine and check
out this legendary scooter in detail. My sincere
thanks go out to Mark and Anne for their time
and for bringing the scooter to the photoshoot
and Norrie Kerr for his time explaining the
details and revealing some of the secrets of a
very special Vespa.
Big Chris