The original Le Mans was continually developed and spawned several later models, a final versions appearing in the early 1990s.

The basic design of the Le Mans remained essentially the same throughout the production run: The engine developed from the earlier Moto Guzzi 750s is an aircooled 90 degree OHV V-Twin was at the time an already proven Moto Guzzi design that had been in production in various forms since the late 1960s.

The V-twin configuration gives improved ground clearance over an opposed 'Boxer' layout, allowing the engine to mounted low in the chassis.

The single camshaft mounted in the crux of the V operates the 2 valves (per cylinders) via pushrods and is driven by a short double row camchain.

Designed by Lino Tonti for the Moto Guzzi V7 Sport, the substantial chassis was made from straight tubing, highly triangulated and was praised at the time for its excellent handing.

Compared to its roadster sibling, the T3, the Le Mans had higher-compression domed pistons, larger engine valves, and Dell'Orto 36 mm pumper carbs with filterless velocity stacks.

The Le Mans had three production runs with very slight modifications: The first run, Series A, had a round CEV taillight, low 'racer' seat that was unusually a made of a single molded foam item, silver fork legs and various minor detail changes and continued in production until at least September 1976.

[1] Series B bikes and had these modifications: a De Tomaso-designed rectangular taillight with a modified rear mudguard, black fork sliders, small heel-plates, cast fuel taps and a more generous dual seat.

The instrument cluster was now dominated by a large white faced Veglia tachometer inside a moulded rubber binnacle.

The engine had improved machining tolerances, revised intake, carburation and exhaust systems all of which gave an increase in power and torque despite the (official) slight drop in compression ratio.

Minor changes were made to the rear suspension, with a longer swinging arm and to the front forks which were now up to 38mm, and had a provision for linked air-assistance.

In 1993 Steve Attwood rode a Le Mans Mk III to victory in the US Iron Butt Rally covering 12,458 miles (20,049 km) in 11 days.

[8] Commonly known as the 'Big Valve' engine, Moto Guzzi claimed a (highly suspect) 81 hp / 59.1 kW) @ 7400 rpm.

The wheels themselves were of a new design, the rear was up a size to 3.5 inch, able to take tubeless tyres and a longer swinging arm gave a lengthened wheelbase.

Complaints about the 16-inch front wheel were answered by the following years 1985/86 versions, which had modified flatter topped steering yokes (triple trees) which reduced the trail and were made in steel rather than alloy.

The new bike was now physically longer, higher and larger than the 850cc predecessors but had improved ergonomics and increased performance thanks to the more powerful engine.

[14] Near the end of production the half fairing was updated so it contained a dashboard mounted instruments rather than rubber binnacle upon the top yoke.

[15][better source needed] [16] In 1973 the Le Mans factory prototype finished 4th in the 24-hour race at Barcelona's Montjuïc circuit.

In 1984 Dr John Wittner campaigned and won a Le Mans MK III in the AMA/CCS US Endurance Series Championships.

[8][18] In 1985 Dr John Wittner again returned with a Le Mans 1000 to win the AMA/CCS US Endurance Series Championships in the Heavyweight Modified Class.