Ducati 500GTL and Ducati Sport Desmo
exhaust system was sourced from Lanfranconi. Soon a desmo version of the 350 appeared which was vital in the home market as motorcycles of 350cc or less received a more favourable rate of taxation.
In the production version, the oil for the wet sump engine was circulated by a gear pump for pressure feed as well as scavenging, but the lubricant itself had a hard life and the factory recommended it be changed every 5,000km – something that many owners failed to do, with disastrous results. The forged crank, with its two plain bearings and splitshell big ends, required clean lubricant and plenty of it, and the gearbox and helical gear primary transmission with its wet clutch shared the same oil, so dual oil filters – one a tubular nylon strainer and the other a replaceable paper element – were required. On the electrical side was a crankshaft-mounted Motoplat 200W alternator, coils and transistorised regulator made by Ducati’s Spanish affiliate Mototrans company, with a set of points mounted behind the left cylinder where it was all-but inaccessible. Reliability was not a strong point, and with no kick starting option, failure of the electric starter resulted in a stationary motorcycle and an exasperated owner. Despite all the pain and the decade long gestation period, the parallel twins were never successful; shunned by the Ducatisti as not being a legitimate part of the Ducati family. With Italjet only taking engine units as it required for forward orders, stocks of the power units piled up back at the Ducati factory until the plug was finally pulled on the model in 1983. The real death knell for the parallel twin had been sounded as far back as November 1977, when Taglioi’s brilliant Pantah v-twin, with the toothed belt camshaft operation first seen on the 1973 Ducati 500cc GP racer, was unveiled. However in typically defiant fashion, the factory responded with still another version of the parallel twin, the 500GTV. This model, introduced for 1978, was in touring style with the frame, wheels and engine (painted black) from the Sport Desmo, but different tank, seat and side covers. When the 500cc Pantah finally came on stream in 1980, it was the end of the GTV – almost. The factory had such a stock of unused parallel twin engines, it moved production back from Italjet to Borgo Panigale and kept up assembly until stocks finally, and permanently, ran out. This ended a saga that lasted 20 years, but is today a dim memory in the company’s history, and certainly not one that is