2018 Yamaha F4 Portable Tiller F4SMHA Outboard Motor

Yamaha's 2018 F4 Portable Tiller (F4SMHA) uses the short, 15-inch shaft, suited to a shallower transom than the L-shaft version of the same engine. It is a single-cylinder, 139 cc four-stroke rated at 59 lbs dry, with a built-in carrying handle for moving it between boat and storage. Before you order Match transom height to the 15-inch shaft, since this short-shaft version sits differently on the hull than Yamaha's longer-shaft F4. Steering friction and the F-N-R shift handle are both tuned for one-hand control from a tiller, and a 5-step trim adjustment pairs with a 3-step shallow water drive for working skinny water close to shore. Storage and starting Starting is manual, aided by an easy-grip knob and a decompression mechanism that lightens the pull. The motor can rest on either side or on its front grip without oil leaking out, which matters if it moves on and off a boat often. An auxiliary priming pump built into the fuel line helps it restart smoothly after sitting unused, and a tilted, water-resistant fuel filler cap plus a built-in fuel strainer keep the 1.1-liter see-through tank running clean. 87-octane regular unleaded keeps it running, with an oil capacity of about six-tenths of a liter, and an optional kit adds a 6-amp alternator for small electronics. What is the compression ratio? 8.9:1, run through an overhead-valve, carbureted induction system cooled by raw water with thermostatic control. What is the top rpm at full throttle? Around 5000 rpm. Specifications Engine Engine Type Four-stroke 1-cylinder Bore x Stroke 62 x 46 mm (2.44 x 1.81 in.) Displacement 139 cc (8.5 ci) Starting Manual Dimensions Shaft Length 15 in. Weight 27 kg (59 lb.) General Full Throttle Operating Range 4,000-5,000 rpm Gear Ratio / Shift 13/27 (2.08:1) / F/N/R Fuel Induction OHV (overhead valve) Alternator 6 Amp (optional: requires charging kit) Cooling Raw water, Thermostatic Control