All the professional models are fitted with a variable advance digital coil with rpm limiter: the result is a smoothly running engine and improved cooling, even in difficult weather. The handle and fuel tank are separate from the body of the machine, to reduce the fuel/oil mixture temperature and minimise the transmission of vibration. The oil pump is in aluminium, automatic and adjustable, so that the flow rate can be adapted in accordance with the task to be performed, thus avoiding wastage.
The 956, 962, GS 651 and GS 720 models are equipped with a reliable steel engine supported by a piston with 2 rings, and a cylinder with decompression valve to ensure easy starting without recoil kick-back.