Suzuki GT380C

Suzuki GT380C
Manufacturer	Suzuki
Production	1978
Engine	Two stroke, transverse three cylinder
Compression ratio	7.2:1
Top Speed	153 km/h / 95 mph
Ignition	Battery and coil
Transmission	6 Speed
Suspension	Front: Telescopic fork, oil dampened Rear: Dual shocks, springs, 5-way adjustable
Brakes	Front: Single 275 mm disc Rear: 180mm drum
Front Tire	3.00-19 4PR
Rear Tire	3.50-18 4PR
Wheelbase	1379 mm / 54.3 in
Seat Height	787 mm / 31 in
Weight	171 kg / 377 lbs (wet)
Oil Capacity	1.3 Liters / 2.7 US pt / 2.2 Imp pt
Recommended Oil	Suzuki ECSTAR 10w40
Fuel Capacity	15 Liters / 4.0 US gal / 3.3 Imp gal
Manuals	Service Manual

It could reach a top speed of 153 km/h / 95 mph.

Engine

The engine was a Air cooled cooled Two stroke, transverse three cylinder. The engine featured a 7.2:1 compression ratio.

Drive

Power was moderated via the Wet, multiplate.

Chassis

It came with a 3.00-19 4PR front tire and a 3.50-18 4PR rear tire. Stopping was achieved via Single 275 mm disc in the front and a 180mm drum in the rear. The front suspension was a Telescopic fork, oil dampened while the rear was equipped with a Dual shocks, springs, 5-way adjustable. The GT380C was fitted with a 15 Liters / 4.0 US gal / 3.3 Imp gal fuel tank. The wheelbase was 1379 mm / 54.3 in long.

Photos

Overview

Suzuki GT 380

Suzuki launched its air-cooled two-stroke triples GT380 and GT550 in 1972. An water-cooled three-cylinder GT750 had already been presented a year earlier and the 380 and 550 followed the design of the flagship model.

The GT380 and GT550 were predicatable and sporty motorcycles, but

up to a

point. At touring speeds they were comfortable and

smooth, but twisting the grip farther brought a wobble and cornering at higher speeds showed the limitations of the suspension, swinging arm and the tube frame.

The GT engines were less highly tuned than for example the Kawasaki triples. It was tuned for the long run. Porting, timing,

compression, carburetor size etc. were all chosen to deliver smooth power at the expence of maximum power. It made the Suzuki GTs more reliable than fast. The odd 3 to 4 exhaust system and rigid foot pegs also limited the leaning angle and the sporting nature of the bike. The GT triples were

simply made for touring and not for sport-styled

riding.

The Ram Air System (introduced in all of the air-cooled GT models) that

forced the cool air to pass through the

cylinders and behind the block was a new developement, tested earlier on Suzuki's TR500 racers. It is an simply an air scoop that ducts cold air directly onto the cylinder head the help the cooling on the engine. It was a known problem

that two-stroke engines lost power when the cylinder head temperature rose

too much. Cooling problem plagued

other two-stroke triples but the Ram Air System made the Suzuki GT triples less

suspective to the charasteric two-stroke power loss caused by too high a cylinder head temperature after

a long, hard run. Nevertheless

the GT triples still had a reputation for

the middle piston seizing.

Suzuki's automatic system mixing

fuel and oil had been refined for the GT models, providing

less exhaust smoke, now called CCI. A clever new item in the early seventies

was the vacuum-operated petcock was first used on the GTs and later used on all Suzuki mototrcycle models.

Both triples saw some minor improvements every year of their production but after only few of years production

the two-stroke engined street bikes were terribly out of fashion. Although

the GT380 was as strong and reliable as a four-stroke of

equal displacement the rather high fuel comsuption of the two-strokers was

suddenly an issue, when the gasoline prizes rose in the seventies.

Even Suzuki itself dug a grave to its two-stroke models by launching its highly popular GS series with four-stroke

angines. It was actually forced

to change their minds and start making four-stroke engines. The

tighter emission regulations in America sounded the death knell for most two-strokes.

Source suzukicycles.org

Make Model	Suzuki GT 380C
Year	1978
Engine Type	Two stroke, transverse three cylinder
Displacement	371 cc / 22.6 cu in
Bore X Stroke	54 x 54 mm
Compression	7.2:1
Cooling System	Air cooled
Exhaust	3 into 4, stainless steel
Induction	3 x 24mm Mikuni carburetors
Ignition	Battery and coil
Starting	Kick
Max Power	27.7 kW / 38 hp @ 7500 rpm
Max Torque	38 Nm / 3.9 kgf-m / 28 lb-ft @ 6000 rpm
Clutch	Wet, multiplate
Transmission	6 Speed
Final Drive	Chain
Front Suspension	Telescopic fork, oil dampened
Rear Suspension	Dual shocks, springs, 5-way adjustable
Front Brakes	Single 275 mm disc
Rear Brakes	180mm drum
Front Tire	3.00-19 4PR
Rear Tire	3.50-18 4PR
Dimensions	Length: 2090 mm / 82.3 in Width: 815 mm / 32.1 in Height: 1125 mm / 44.3 in
Wheelbase	1379 mm / 54.3 in
Ground Clearance	145 mm / 5.7 in
Seat Height	787 mm / 31 in
Wet Weight	171 kg / 377 lbs
Fuel Capacity	15 Liters / 4.0 US gal / 3.3 Imp gal
Oil Capacity	1.3 Liters / 2.7 US pt / 2.2 Imp pt
Standing ¼ Mile	13.8 sec
Top Speed	153 km/h / 95 mph