The Yamaha YFZ350 is more commonly known as the "Banshee" in the ATV community. It is the only twin-cylinder two-stroke ATV available. The Banshee was designed to be a high-performance racing ATV with no equals. The Banshee was introduced as a 1987 model and it continues to be the longest-offered high-performance ATV of all time.
The Banshee has undergone, relatively, few evolutionary enhancements. Beginning in 1991, Yamaha improved the front suspension by incorporating a double wishbone design. Prior to 1991, the upper lateral arm of the front suspension was composed of, what was nicknamed, "J-arms". These J-arms represented a compromise between available space for the engine and strength of chassis. By slightly re-arranging the exhaust pipes, the upper wishbone design became possible. The easiest way to distinguish a Banshee's model year is by its colors. For the most part, Yamaha revised the colors of the Banshee almost on a yearly basis.
The basic engine design of the Banshee was shared with Yamaha's RZ350 street bike. These two engines appear to be the same from the exterior, but differences in gear ratios, connecting rod lengths, and cylinders set them apart. Most notably, the RZ350 has the YPVS "power valves" that was omitted from the Banshee engine.
The Banshee remains, to this day, Yamaha’s greatest-powered ATV. Even 600cc ATVs from Yamaha can not match the sheer power offered by the Banshee's high-revving two-stroke twin.
Standard YFZ350 features include:
Source of data: genuine Yamaha service manual (for the most
part)
Model years this data is valid for: 1987-1990
Manufacturer: Yamaha
Model: YFZ350T Banshee
Wheelbase: 1280mm, 50.4"
Ground clearance:135mm, 5.31"
Maximum load capacity:
Overall height: 1080mm,
Overall length: 1855mm, 73"
Overall width: 1100mm, 43.3"
Seat height: 780mm, 30.7"
Footpeg height:
Fuel capacity: 12 liter, 3.17 US gallons
Engine weight:
Engine type: twin-cylinder, two-stroke
Fuel: premium gasoline
Cooling system: liquid cooling
Induction system: reed valve
Air filtration: oiled foam
Displacement: 347cc
Bore: 64mm, 2.520"
Stroke: 54mm, 2.126"
Compression ratio:
Corrected compression ratio: 6.5:1
Cold cranking pressure:
Carburetor type: two Mikuni VM22SS
Lubrication type: premix 24:1
Ignition type:
Ignition timing advance: 17°@1200rpm to ~22°@3500 then retard
10° every 5000rpm
Electrical system: Nippondenso magneto and CDI units, 12volt
Lighting system: two 30w/30w headlights, one 3.8w taillight,
11.5v @ 2500rpm, 16.3v @ 8000
Maximum torque output:
Maximum power output:
Starter type: rearward kick
Transmission type: 6 speeds, constant mesh
Clutch: manually operated, wet multiplate
Transmission primary ratio: 66/23, 2.869
Transmission 1st gear ratio: 32/13, 2.461
Transmission 2nd gear ratio: 29/16, 1.812
Transmission 3rd gear ratio: 27/18,1.500
Transmission 4th gear ratio: 25/20, 1.250
Transmission 5th gear ratio: 23/22, 1.045
Transmission 6th gear ratio: 21/24, 0.875
Transmission final ratio: 42/13, 3.230
Front brake type: disk, single piston calipers
Front brake quantity: two
Rear brake type: disk, single piston caliper
Rear brake quantity: one
Camber:
Caster: 9°
Toe in: 0-10mm, 0-0.39"
Trail: 40mm, 1.57"
Rake:
Steering angles:
Turning radius: 3600mm, 142"
Curb weight:182kg, 401 lbs
Dry weight:
Weight bias:
Final drive type: #520 chain
Front suspension travel: 220mm, 8.66" double wishbone
Front shock travel: 110mm, 4.33"
Front shock type: coil over damper
Front tire size: AT21x7-10
Front wheel type: 10x6AT aluminum panel wheel
Front wheel pattern:
Rear suspension travel: 220mm, 8.66" swingarm with linkage
Rear shock travel: 86mm, 3.39"
Rear shock type: coil over gas-charged damper with remote
reservoir
Rear tire size: AT22x10-9
Rear wheel type: 9x8.5AT aluminum panel wheel
Rear wheel pattern:
Factory warranty:
Original MSRP:
Rear suspension trademark name:
Front suspension rebound adjustment:
Front suspension compression adjustment:
Front suspension preload adjustment:
Rear suspension rebound adjustment:
Rear suspension compression adjustment:
Rear suspension preload adjustment:
