Thursday, October 29, 2015

1969 BSA LIGHTNING- Customer Hardtail

The BSA Lightning was designed as the all-round sports machine of the 1960's, planned largely for export to the US market to complement the touring Thunderbolt and the later development, the supersports Spitfire. Development of the engine aimed to make it more reliable, quieter and less prone to oil leaks, with top speed sacrificed to improve mid-range and rideability. Nevertheless, with twin carburetors the A65L could still reach 108 mph (174 km/h).

A close ratio gearbox combined with a high lift camshaft made for lively acceleration and performance at higher rpm than the standard A65. The bottom gear was a bit high, however, so riders had to learn to slip the clutch up to 10 mph. Above 5000 rpm customers also complained about excessive vibration, with a tendency to weave above 90 mph.

From 1969 the Lightning was improved with balanced exhaust pipes, redesigned silencer-internals, widened crankcase-half mating faces and a twin leading shoe front brake. When road testing, Motorcycle Sport found the natural cruising speed to be 70 mph (110 km/h), but was impossible to ride comfortably at more 5,500 rpm in the higher gears due to severe vibration, accordingly no top speed runs were attempted.

Engine          654 cc (39.9 cu in) OHV parallel twin
Top speed  112 mph (180 km/h)
Power          52 bhp (39 kW) @ 7,000 rpm (claimed)
Transmission  Four speed gearbox to chain final drive
Brakes          Drum front 8.0 in (200 mm), rear 7.0 in (180 mm)
Wheelbase  56 inches (1,400 mm)
Seat height  32.3 in (820 mm)
Weight          395 lb (179 kg) (dry)
Fuel capacity 4.8 US gal
Oil capacity 110 US fl oz engine, 17 US fl oz gearbox
Fuel               58 mpg

A local customer brought this bike in a few days ago. A rolling chassis, and several boxes of engine parts and other bits. The plan is pretty simple for this one... get it running!

To start we have gone through all the boxes, cataloging and cleaning parts as we go. The top end is essentially ready to go since the customer had some new parts that came with the bike when he purchased it. It only needed minor cleaning, a fresh coat of paint, and some new gaskets.

Most of the missing or damaged parts are on the bottom end and have been sourced and are on the way to the shop.

Some upgrades will include; .060 over pistons, twin flatslide carbs, and a Sparx electronic ignition with a new stator, and coils.

***Update Dec 15th 2105***
 Sealed AGM battery

Flat slide carbs with UNI filters

 New Stator

 Sparx Electronic Ignition

 Microphone tail light

She's done. Starts on the first kick, even in the cold winter. I'd say we got the job done!

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