The 1978-1988 Suzuki GS850 Fours repair manual by Haynes covers 843cc 4-cylinder models, including:

• Suzuki GS850GN, U.K. 1979, U.S. 1978-1979
• Suzuki GS850GT, U.K. 1979-1980, U.S. 1979-1980
• Suzuki GS850GLT, U.S. 1979-1980
• Suzuki GS850GX, U.K. 1980-1984, U.S. 1980-1981
• Suzuki GS850GLX, U.S. 1980-1981
• Suzuki GS850GZ, U.K. 1983-1985, U.S. 1981-1982
• Suzuki GS850GLZ, U.S. 1981-1982
• Suzuki GS850GD, U.S. 1982-1983
• Suzuki GS850GLD, U.S. 1982-1983
• Suzuki GS850GE, U.K. 1985-1986
• Suzuki GS850GG, U.K. 1986-1988

Book Excerpt: 1978-1988 Suzuki GS850 Fours Repair Manual ENGINE, CLUTCH AND TRANSMISSION

DISMANTLING THE ENGINE UNIT | REMOVING THE CYLINDER HEAD, CYLINDER BLOCK AND PISTONS

1. Do not disturb the cam followers and adjusters at this juncture. These components should be left in place until the examination stage. A useful method of ensuring these components stay in place, is to place a length of wood along the tops of these components, in the position of the camshafts; something similar to a section of a broom handle would be ideal. Then replace one bearing cap on each wooden "camshaft" and lightly bolt into position. The cylinder head is retained by twelve 10mm nuts and three 6mm bolts. Loosen and remove the 6mm bolts from each end of the cylinder head (below the spark plugs of cylinders No 1 and 4) and remove the third 6mm bolt from the front of the cam chain tunnel. With the bolts removed, loosen the twelve nuts (8 have ordinary hexagon heads and 4 are chromed dome nuts) in the reverse order to that given in Fig. 1.21 which accompanies Section 52. To aid correct dismantling and rebuilding, the number of the nut is stamped next to it in the head casting. The nuts must be loosened evenly in this sequence, to avoid stressing the cylinder head casting.
2. Separate the cylinder head from the gasket, using a soft-headed mallet. Strike only those portions of the casing which are adequately supported, taking special care not to damage the fins. Under no circumstances should levers be used between the mating surfaces of the cylinder head and cylinder block in an effort to facilitate separation. This action will lead to damage to the faces with subsequent risk of leakage. When lifting the cylinder head from position, the cam chain must be guided through the central tunnel and prevented from falling free. An extra pair of hands is beneficial at this stage. Before raising the cylinder head from position, remove the forward cam chain guide blade; this guide blade lifts out.
3. Separate the cylinder block from the base gasket, using the technique described for the cylinder head. Once again, levers should not be used. Lift the cylinder block upwards along the holding down studs until the piston skirts are visible but the piston rings are still obscured by the cylinder bore spigots. If a top-end overhaul is to be carried out, the crankcase mouths must be padded with clean rags to prevent pieces of broken piston from falling into the crankcase. The padding will also prevent the ingress of foreign matter during further dismantling or work.

ELECTRICAL SYSTEM

STOP AND TAIL LAMP: REPLACING THE BULBS

1. The tail lamp unit on the GS850 GN and GT models contains two bulbs. The larger of the two bulbs is of the twin filament type with, for the US market, a rating of 8/23W (3/32 cp) or for the UK market, a rating of 5/21W. The higher rated filament operates to give visible warning when the brake is applied, and the lower rated filament acts as a permanent warning lamp with the lights switched on. The second, single filament bulb (8W US models, 5W UK models) is used to illuminate the rear license plate. Stop lamp switches operate in conjunction with both the front and rear brakes in order that the system meets the statutory requirements of the country or state to which the machine is exported.
2. To gain access to the bulbs, unscrew the four crosshead screws which retain the plastic lens cover in position. The bulbs have a bayonet fitting and the tail/stop lamp has offset pins. This is so that the stop lamp filament cannot be inadvertently connected with the tail lamp and vice versa.
3. On the GLT model, there is only one tail/stop lamp bulb fitted, rated at 8?23W (3/32 cp). Due to the differing styling of the unit, a separate license plate illuminating bulb is not warranted. When replacing the bulb on this model, note that there are only two lens retaining screws, and they enter the unit from the rear; that is, the screw heads reside in the chromed backplate of the lamp unit.

Subject: 1978, 1979, 1980, 1981, 1982, 1983, 1984, 1985, 1986, 1987, 1988 Suzuki GS850 Four service, maintenance, repair. ISBN-10: 1850105715 | ISBN-13: 9781850105718 | Haynes 536