Yamaha FJ

The FJ1200 uses a four cylinder in-line layout and is air-cooled. Sixteen valves are operated by a chain-driven double overhead camshaft; valve clearances are adjusted using shims. The four constant-velocity carburettors are mounted in a bank behind the cylinders and feed each cylinder through a short intake manifolds. Four exhaust downpipes join a box below the engine where the gases are split to exit through two silencers (mufflers). The crankshaft is geared directly to the clutch, no counter balancer shaft is used. Starting is by electric starter only. Lubrication is wet sump using a trochoid pump; an oil radiator assists with cooling.[2] Both the FJ1100 and FJ1200 were fitted with an additional fuel vapour recovery system to comply with California emission regulations.[3]

1990 FJ1200 Model 3CV with standard windscreen

The FJ1200 uses a five-speed constant-mesh sequential manual close-ratio gearbox. The clutch is of the wet, multiple-disc diaphragm spring type and is hydraulically operated. Final drive is by O-ring chain and sprockets.

The frame of the FJ1200 is manufactured from mild steel box-section and uses a perimeter layout, the fairing and upper rear section use separate cylindrical tubing sub-frames. The rear shock absorber is placed vertically behind the engine and connects to a swinging arm made from extruded aluminium alloy (note: later 3XW models have mild steel swinging arm) via several forged aluminium rocker arms. The 17-inch front wheel is held between 41 mm spring and oil damped forks. The FJ1100 and early FJ1200 models featured adjustable anti-dive units and a smaller diameter 16-inch wheel. The FJ1100 and early FJ1200 used twin ventilated disc brakes for the front wheel with a single ventilated disc at the rear. FJ1200 models, 3CV & 3XW, used solid front discs but retained the rear ventilated disc, front brake calipers were upgraded to a four-piston design. An anti-lock braking system was used on the FJ1200A. A full fairing protects the rider, varying height fixed windscreens were available as options.[4]

FJ1200 with ABS brakes

The FJ1200 features a standard 12 volt electrical system. The alternator and starter motor is mounted behind the cylinders. Nippondenso Transistor Controlled Ignition (TCI) is used in conjunction with two coils. Yamaha's self-cancelling indicator unit is used and a variable resistance gauging system is used to monitor engine oil contents with associated warning lights. A large fuel gauge is provided as is a low fuel level warning light. A digital clock is also fitted. A safety feature of the FJ1200 is that the engine ignition is cut if the first gear is selected with the side-stand down, this is now commonplace on modern motorcycles.[5]