Suzuki GS450GA Suzukimatic
1982—1985

I have tried to tell the Suzuki GS 450 GA model history on this page as I know it. I would be grateful of any contributions — sales brochures, magazine ads, magazine articles, pictures, specs, facts, corrections etc. Please scan the material in JPEG format (large enough that all the details are visible) and send them to me. Please tell me the source and the publication date if possible. If you send me pictures of your own bike, please follow these instructions.

Four years after Honda presented its beginner-friendly motorcycle CB400A with ”Hondamatic” transmission, Suzuki launched GS450GA ”Suzukimatic” motorcycle. None of them had an automatic transmission. Both ”Hondamatic” and ”Suzukimatic” did eliminate the need for a clutch, but did not eliminate the need for manual shifting, though it did reduce it from five or six speeds to only two. Let me explain: The Suzukimatic transmission has a hydraulic torque converter and a two-speed transmission, shifted with a lever on the left side of the engine, just like a normal motorcycle. A lightbox on side of the speedometer indicates when the bike is on neutral, low or drive. There is a lever on the left side of the handlebar, but it's not a clutch lever. It's a parking brake, connected to the drum brake at the rear wheel. It also has an engine much like the normal GS450: DOHC twin, 2 valves per cylinder, 2 carbs, good power and all the rest. Add to that a shaft drive, because this isn't a performance machine, it's a convenience machine. All these parts go into what looks like a GS450T, the traditionally-styled Suzuki Twin, with its wire spoke wheels, low stepped seat, teardrop gas tank and even such old-fashioned things as chromed fenders. There's no clutch. It has been replaced by a hydraulic torque converter. The standard 5-speed transmission has been replaced with a 2-speed gearbox. What has remained from the standard GS450 are the power-producing parts of the engine: cylinders, head, crankshaft, and all the connecting bits like cam chain, gear-driven counterbalancer and chain tensioner. Because of the shaft drive and different transmission, the engine cases are different from those of the normal 450. The camshafts have less duration and lift, the changes were designed to increase low speed torque at the expense of peak power. On the standard 450, the dual overhead cams provide 280° of duration each, with 74° of overlap. Intake valve lift is 8.5mm, exhaust lift is 8mm. For the Automatic, intake duration is 256°, exhaust is 260°, overlap is 50° and lift is 7.6mm on both. Below 7,000 rpm the Automatic makes considerably more torque than the standard Suzuki, about 10 percent more from 4,000 to 7,000 rpm. That's the range where the torque converter engages, and the new cam timing makes it very engaging. The oil pump has a higher volume that the standrad GS450. Main bearings have three oil feed holes instead of two, a different rod bearing material is used, oil control jets below the cylinder and below the counterbalancer bearing inserts are used and the lower pan in the crankcase is tapped for lines running to the oil cooler. Maximum oil pressure in the Automatic is limited to 99 psi, up from the 71 psi limit of the standard 450. Other regulators maintain a relatively constant 24 psi to the torque converter. The torque converter generates considerable heat, requiring a heat shield on the left side of the engine and the oil coolerin in front of the cylinders. There is no kickstarter. Ordinarily motorcycles without kickstarters can be bump started when the battery goes dead (when, not if), but the Automatic doesn't allow for bump starting. When the battery goes the bike doesn't go. The Suzuki GS450GA is an easy motorcycle to ride. It starts instantly with the choke lever on the left handgrip turned on. Suzuki has had carburetion difficulties on the other 450s, but the Automatic got new 34mm Mikuni CV carbs with an accelerator pump that eliminated low speed stumbles. It also had improved suspension. The original GS450 suspension was soft in front and firm in back, the combination making the ride less than ideal and the handling mushy. Spring and damping rates have been adjusted. The suspension is now well suited to the motorcycle, but there's no damping adjustments, but just air caps on the forks and preload adjustment on the rear suspension units. Some maintenance chores on the Suzuki aren't easy to do. Removing the rear tire, for instance, takes about half an hour. Because the mufflers are an inch too long, and positioned right where the axle has to be pulled, the shocks have to be disconnected or the exhaust removed in order to pull the axle and remove the rear wheel. Even removing the seat requires unbolting, unlatching and sliding it off hooks. There is no storage area anywhere under the seat.

1982 Suzuki year code: Z

1982 Suzuki GS450GA with shaft drive and semi-automatic transmission

1982 Suzuki GS 450 GA Overall Length: 2 145 mm (84.4 in) Overall Width: 840 mm (33.1 in) Overal Height: 1 135 mm (44.7 in) Seat Height: 740 mm (29.1 in) Wheelbase: 1 420 mm (56.5 in) Ground Clearance: 140 mm (5.5 in) Dry Weight: 180 kg (396 lbs) Engine: Air-cooled 448 cc parallel twin, DOHC, 4 valves. 43 hp (31 kW) @ 9 000 rpm, 33.9 Nm (3.46 kg-m) @ 7 000 rpm Click on the image for larger format.

1985 Suzuki year code: F

1985 Suzuki GS 450 GA Overall Length: 2 145 mm (84.4 in) Overall Width: 845 mm (33.3 in) Overal Height: 1 150 mm (45.3 in) Seat Height: 725 mm (28.5 in) Wheelbase: 1 420 mm (55.9 in) Ground Clearance: 145 mm (5.7 in) Dry Weight: 184 kg (406 lbs) Engine: Air-cooled 448 cc parallel twin, DOHC, 4 valves. 43 hp (31 kW) @ 9 000 rpm, 33.9 Nm (3.46 kg-m) @ 7 000 rpm Click on the image for larger format.

More: Suzuki GS models

More: All Suzuki models

Sources: Cycle World, Suzuki Motor Company

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