ENGINE: four-stroke single cylinder, 10° inclined, valve in head desmodromic distribution, with an 80° angle between each other, commanded by overhead camshaft and rocker arms, intake valve diameter 40 mm, drain valve 36 mm diameter. Bore and stroke 86 x 75 = 436 cc. Compression ratio 9.3: 1 Distribution diagram: intake open 70 ° before TDC and closes 82 ° after the BDC, the exhaust opens 80 ° before BDC and closes 65 ° after TDC. Clearance between valves and rockers for phasing: 0.10 ÷ 0.15 mm at suction and discharge; normal operating clearance when engine is cold 0.10 mm. IGNITION: a distributor controlled by a gear chain on the right side, automatic advance 28 ° ± 2 °, 0.3 mm contact gap, spark plug 260. LUBRICATION: Forced with a gear pump and oil in the crankcase saucer, capacity 2.5 kg, oil AGIP F.1 SAE 40/50 in summer, 20/30 in winter, integral change andfilter cleaning every 2000 km. POWER: fall type, premium gasoline 98/100 octane, 10 liter t