Motorcycle Classics

Hot Rod: BSA Spitfire Mark III

1967 BSA Spitfire Mark III
Claimed power:
55hp @ 6,800rpm
Top speed: 117mph (period test)
Engine: 654cc air-cooled OHV parallel twin, 75mm x 74mm bore and stroke, 10.0:1 compression ratio
Weight (dry): 382lb (174kg)
Fuel capacity/MPG: 2gal (7.5ltr)/40-60mpg
Price then/now: $1,466/$4,000-$13,000

In the 1960s, BSA was known for flashy bikes with bright
colors and lots of chrome. But there was more to the English import than just
shine. Under all that makeup was a reliable motorcycle that handled well, ran
fast and stopped when asked.

Birmingham Small Arms Company’s first motorcycles in 1903
were single-cylinder machines, with a line of V-twins following in the 1920s.
The first BSA parallel twin, the A7 designed by Val Page, Herbert Perkins and
David Munro in 1939, was put on hiatus when World War II started and finally
appeared in 1946.

BSA weathered the war well, and by the 1950s it had the
largest range of any motorcycle manufacturer in the world. Most of the bikes
BSA sold were the smaller, single-cylinder commuter cycles heavily in demand by
British workers. And while the company had a firm policy against factory road
race involvement, BSA built single-cylinder Gold Stars for clubman racers in England and flat track competition in the United States.

BSA’s better twin

By this time, BSA’s parallel twin had morphed into two
versions, the 497cc A7 and the 646cc A10. In order to raise money to pay its
war debt, the British government pushed English companies to export. As a
result, a lot of BSA twins were sent to the United States, where the market for
sport motorcycles was booming. Indian motorcycle distributor Hap Alzina was
importing BSAs to the West Coast while Rich Child, the former head of Harley-Davidson’s
Japanese subsidiary, was in charge of distribution east of the Mississippi. The
reliability and economy that drew British consumers did not draw U.S. riders,
who were more interested in speed. American motorcyclists generally had little
use for BSA’s lightweights, but were enthusiastic about BSA twins.

An obvious way to prove performance is on the race track.
BSA didn’t like to sanction racing, but the company had little choice if it
wanted to sell bikes in the United
States. American racers found that BSA twins
responded well to tuning, and with the right setup were competitive in flat
track and offroad events. In 1954, BSA lent assistance to a team led by AMA
National Champion Bobby Hill for that year’s Daytona beach race, and the BSA Wrecking
Crew, as it became known, swept the first five places. Other National winners
on BSA singles and twins included Jody Nicholas, George Everett and Dick Mann.

One of the most consistent BSA flat track stars was Al
Gunter. He moved to BSA in the early Fifties and racked up seven career wins in
national racing events. His home track was Ascot
Park in Southern
California, where he won regularly. Other BSA riding masters at Ascot were Sammy Tanner, Blackie Bruce, Jack O’Brien and
Neil Keen. Together, they were known as the Ascot Wrecking Crew.

BSA continued to develop its parallel twin, and in January
1962 introduced a major revamp of both the A7 and A10 twins. The new engines
were based on a common platform, with the major difference between them being
the 75mm bore of the A65, which with the 74mm stroke common to both engines
gave 654cc cubic capacity. The smaller A50’s bore of 65.5mm gave 499cc.

The A65 engine used vertically split aluminum alloy
crankcases with a one-piece crankshaft resting on ball bearings on the drive
side and a plain bushing on the timing side. The cylinder was still cast iron,
while the head was aluminum alloy. Valves were operated by pushrods, and
lubrication was dry sump.

The 4-speed transmission was in unit instead of a separate box
bolted to the engine as on the A10, and an alternator handled the 6-volt
electrics. Two sets of points were mounted on a single plate with an automatic
advance mechanism.

The frame was similar in design to the one used on the last
A10s, a dual downtube cradle with a single backbone tube under the seat.
Telescopic forks in the front and Girling shocks in the rear absorbed the
bumps, and the single-leading-shoe brakes were 8 inches diameter in front and 7
inches in the rear.

Going faster

In 1964 BSA started hot rodding the A65. The Rocket A65R had
the compression upped to 9.0:1 from the standard 7.5:1, with a hotter cam and
siamesed exhaust pipes. British riders still wanted easy maintenance and fuel
economy, but American riders wanted higher bars, smaller tanks and more
horsepower, so the American importers convinced BSA to build four special
U.S.-only models.

The result was the 499cc offroad competition Cyclone with no
lights and open pipes, and the 654cc Thunderbolt with high bars, a small tank and
the hot engine. A twin-carb version of the Thunderbolt was named the Lightning.

The last of the four U.S.-only models was the 654cc BSA
Spitfire Hornet. Like the Cyclone, it was produced in response to American
demand for a hot offroad/desert racer. Equipped with the twin-carb head fed by
a pair of 1-1/8-inch Amal Monobloc carburetors and available with either 9:1 or
10.5:1 compression, it had a 2-gallon fiberglass gas tank, a high performance
cam and straight-through pipes.

In line with BSA’s East/West Coast distributorships were
separate East Coast and West Coast models. The East Coast version had high
pipes and the West Coast model had low pipes. If riders wanted to hit the
street, BSA’s ET (energy transfer) ignition system could be easily adapted to
add lights.

By this time, BSA was experiencing cracks in the corporate
wall. Better wages for English workers meant many of BSA’s get-to-work
customers were buying inexpensive automobiles coming on the market, and
Japanese motorcycles were being imported to England
and America
in record numbers.

Making matters worse, the British manufacturers weren’t
reinvesting their profits into developing their products. In the 1960s, BSA was
building motorcycles on machine tooling from before World War II. The Japanese
manufacturers, however, were making major investments in tooling and design,
enabling them to offer oil-tight cases, overhead cams and electric starting at
prices competitive to the much more primitive English machinery. Certainly the
Brit bikes handled better, but that was a priority for a minority.

BSA management, who had continued to believe that its
customers were forever loyal, was discovering that the get-to-work rider who
didn’t buy a car was likely to buy a Honda over a BSA.

New bikes

The company tried to cope by fielding state of the art
advertising campaigns and building stylish motorcycles targeted to the sport
rider. For 1965, BSA dropped the single carburetor A65R for the American
market. There were now 11 versions of the twin, but the 499cc versions had to
compete against the new Honda CB450, which had double overhead camshafts,
constant velocity carburetors, an electric start and twin-leading-shoe front

For 1966 there were only six versions of the twin, two 499cc
models and four 654cc. To counter problems with the drive-side ball main
bearing, it was changed to a lipped roller race. This turned out to be a bad
move, as at high speeds the crankshaft could pull to one side and occasionally
cut off the oil supply, resulting in a rod through the cases. Although BSA
never acknowledged the problem, ingenious privateer mechanics developed a more
reliable bearing.

The intake valves were enlarged, the transmission was
improved, a timing notch was added to the flywheel and a balance pipe was added
to twin carb models. The frame was revised, and two-way damping was added to
the forks. A 12-volt system replaced the now outmoded 6-volt lights.

The BSA Spitfire was introduced, replacing the limited
production Lightning Clubman. Amal GP 1-5/32-inch carburetors replaced
Monoblocs and the 190mm front brake from the defunct Gold Star was standard.
The Hornet (with the Spitfire half of the name dropped) continued in production
as a desert racer. Actor Steve McQueen, a dedicated offroad competitor, tested
the Hornet in 1966 and wrote up the test himself for Popular Science. He
praised the BSA’s powerful engine and the excellent air cleaner, but downgraded
the machine for excess weight.

“The Hornet also had a tendency to want to go its own way. I
always had to stay on top of it. But it sure had a good-functioning
powertrain,” McQueen said. “I also think the front forks should be raked on a
more forward angle. With this adjustment, the BSA Spitfire would have a more stable ride
in the rough and would be generally a smoother performer,” he continued.

Cycle World tested a Mark II Spitfire on the
dragstrip and notched quarter mile results of 14.9 seconds, with a terminal
velocity of 89mph. Unfortunately, the once-excellent BSA quality control was
becoming spotty, and a run of defective ignition points cams resulted in
overheating and bad performance.

The problem was corrected the next year with the Spitfire
Mark III. New for 1967 was a new rocker box cover with fins and an inspection
hole (with cover) for checking ignition timing with a strobe. Compression was
reduced a little to 10:1 from 10.5:1, and the GP Amals were swapped for easier
to tune (and cheaper) 932 Amal Concentrics. The dual seat grew a hump in the
rear, and the tires were mounted on aluminum Borrani rims.

The Spitfire was continued for another year (as the Mark IV)
before it was dropped to make room for the Rocket 3 triple. BSA managed to keep
going until 1972, when mismanagement, an aging product line and competition
from Japanese motorcycle manufacturers drove the company into bankruptcy.

Don’s BSA Spitfire

Don Johnson is a little too young to remember the glory days
of BSA flat track racing, but he likes BSA sporting motorcycles. “There’s a
visceral quality to Brit bikes as opposed to the industrial quality of Japanese
motorcycles,” he says.

Don is a collector who rides his bikes. When he happened
across this Spitfire, he found it interesting and bought it. It was all there
and only “slightly restored,” Don says. “I ripped it apart, examined everything
and put it back together. It was all original and within spec.”

All sorts of things can go wrong during the restoration of a
40-year-old motorcycle, but Don lucked out. Pretty majorly, actually, as the
issues that arose were limited to three items: sticking carburetor slides, a
crumbling wiring harness and a leaky fiberglass gas tank. The popularity of old
British motorcycles has given a boost to cottage industries that manufacture
most parts, often with better quality control than the originals, and you can
still buy new Amal carburetors and parts for most Amal models produced since
World War II.

A new wiring harness was easy to find, and Don says that
most of the criticism aimed at Lucas “Prince of Darkness” electrical parts
should actually be directed at the wiring harness. “Some stuff was not up to
the task, but most Lucas components are reliable if you keep them clean and
adjusted,” Don says. “Most parts got no attention until they quit. But Lucas
does have one advantage — you can fix most things at the side of the road.”

The part that was hardest to repair was the gas tank. Old
fiberglass tanks tend to weep and seep. As purchased, the Spitfire had a metal
BSA Lightning gas tank bolted on, with the correct fiberglass tank in a box.
Don discovered a new-old-stock tank in the shop of an acquaintance, and decided
to buy it and use it instead of the compromised original.

Modern gas is hard on old fiberglass tanks, and a partial
remedy is to carefully coat the inside with clear epoxy sealer from outfits
like Caswell. But as experienced users will tell you, coating the inside of a
tank is an art. Don pours in the compound and waits until it looks like it is
starting to harden, then turns the tank so that the excess epoxy settles where
he thinks the leak is. Since the filler neck is proud of the tank, getting
excess epoxy out is very difficult, so Don just turns the tank so the last few
spoonfuls settle at the bottom.

Don says that properly tuned and prepped, the Spitfire isn’t
too hard to kickstart. “It was the hot rod of BSA’s line of twins after they
discontinued the Rocket Gold Star,” Don says. “It’s as fast as a Triumph if
it’s tuned right, and it stops a lot better than Triumphs of the era. Nowadays,
I just like to putt along and enjoy the scenery. It handles very nicely for
what I like to do. The lights are adequate, and the suspension is not bad. If
you do it up right the Spitfire is reliable. It sure is eye-catching. It’s so
red.” MC 

  • Published on Aug 5, 2013
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