ARTHUR'S EMPIRE STAR

were redesigned for dry sump oiling and a single pushrod tube improved their dated appearance. There were significant differences between the Band M group: the bottom ends were similar but not identical, with different shaped timing chests and internal differences. The series machines also had a stronger heavyweight frame and running gear suitable for high speed riding or pulling a sidecar.

The B24 Empire Star (later developed into the Silver Star) was the top of the range roadgoing ohv 350, with the best specification, smartly turned out in chrome and silver. The B26 was the 'sports' ohv 350 and there was also a B25, a competition 350 aimed at the off-road market. The sidevalve B23 was considered the ' touring' option in the 350 class - see sidebar for more on these models.

MThe 1938 B24 seen here ( with a high pipe and the yellow star on its petrol tank) belongs to Arthur Warren. Back in 1976 when he j oined the lnvercargill Vintage Car Club in New Zealand, Arthur was informed that most members had a motorcycle as well as a car. As i t happened, club member Ray had j ust the machine he needed. After $150 passed hands, Arthur became the proud owner of most of a BSA, missing its petrol tank and magdyno. Ray had acquired the B24 in the early 1970s, after spotting i t abandoned behind an old hut at a railway yard.

Arthur put the BSA to one side while he worked on some vintage car projects, but he was always on the l ookout for the missing components. He eventually started the restoration with the engine. The bottom end was OK, but the top end was badly worn. A rebore and a valve j ob were the only real mechanical work required. The bulk of the restoration involved stripping down the whole machine, cleaning parts and repainting, and carefully reassembling it. Arthur's son Tony also helped out with some of the restoration tasks.

The restoration moved along slowly, interrupted by the needs of a young family, finance and car restorations. The missing petrol tank became the major stumbling block- this type was only fitted for one year. Eventually a friend found the correct item, while another pal located a good magdyno while touring Australia and brought i t back in his luggage. The restoration was finally completed in 2007, since when Arthur and Tony have taken the B24 on numerous club runs.

On one such club run a couple of years ago the B24 suffered oil supply problems causing i t to nip up, lose power and generally sound unwell. Tony's initial i ntention was to undertake a top end rebuild, including a rebore, and fixing the oil supply problem. However after stripping the top end Tony spotted some fine cracks j ust below the drive side crankcase mouth. Some very deft work with a Tig welder and files produced an almost imperceptible repair.

Arthur's Empire Star has the optional, sporty upswept high level pipe and silencer. The horizontal Amal carburettor was fitted only for 1938, which is why the petrol tank was unique to that model and year. The

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horizontal carburettor can lead to problems i f allowed to overflow, almost inevitable with the fuel level set correctly at the main j et level. Arthur turns the petrol off every time he stops to prevent flooding.

The gearbox and clutch are robust units, the same as used on larger models in the range. The machine should have chromed wheels with painted centres, with a 20" front wheel and ?"brake. No doubt because of the difficulty of getting 20"tyres, a 19" wheel with a smaller, 5.5" front brake (possibly from the 250cc model) was fitted at some point. The smaller front brake is marginal for such a middleweight machine, fortunately the rear brake works reasonably well.

Tony wants to undertake a couple of improvements: fit a rear saddle and chrome plate and re-paint the petrol tank. Petrol has gotten under the tank paint work and the paint has started to bubble.

FERG'S SPORTS 350

The other 350 in the photos is

Ferg McDowell's 1939 B26, described by

BSA as the 'sports' model to distinguish i t from its sidevalve counterpart. He bought i t on April Fool's day in 2014, which should have been an omen of some sort. The early history of the machine is a bit hazy as a previous owner, Mossy, had misplaced all the early ownership papers. However Ferg eventually traced ownership back to 'a bloke in Dunedin'. The bloke had breathed on i t and used i t successfully in hillclimbs and sprints. It changed hands in the late 1990s and then in 2000 was sold when i t wouldn't start; a local wag suggested that perhaps the Y2K bug had affected the magneto!

The B26 changed hands again in 2006 when Mossy bought it. He said i t went liked the clappers until i t ate the piston. Thereafter i t was fitted with a standard piston and lost a l i ttle of its zing, but still went far better than you might expect. The 350 looks fairly standard on initial examination but i f you compare i t to others then you find that it's been fitted with a post-war gearbox. The well-spaced ratios suit the engine, so Ferg won't be changing it. Also the carburettor is mounted on a slightly l onger i nlet tract, making i t a tight fit under the tank.

Ferg bought the machine shortly after the piston was replaced and, from the outset, the B26 had an issue with oil coming out of the crankcase breather. Mossy believed the problem would go away once the new piston rings had bedded down, however i t continued and Ferg fitted a coke-can oil catcher. The rate of oil loss has slowly reduced, which suggests the cylinder may not have been deglazed before the new piston was fitted.

The other issue was the gearchange. First, second and third slipped in easily but fourth was far more difficult to select. Once engaged i t didn't slip out and disengaged reasonably easily. An initial misunderstanding about the problem, which then sounded like clutch drag, led this scribe to rashly claim he could fix the gearbox. After stripping, rebuilding and trueing the clutch, there was a bit of an improvement, but the fundamental problem remained.

A quick l ook at an exploded diagram of the gearbox resurrected memories of a similar