The 1970-1983 Yamaha 650, XS650, TX650 Twins repair manual by Haynes covers:

• Yamaha 650 XS1, XS1B, XS2, U.S. 1970-1973
• Yamaha TX650, U.S. 1973-1974
• Yamaha XS650B, XS650C, XS650D, XS650E, XS650F, XS650G, XS650H, U.S. 1974-1981
• Yamaha XS650SE, XS650SF, XS6502F, XS650SG, XS650SH, XS650SJ, XS650SK, U.S. 1978-1983
• Yamaha XS650, U.K. 1975-1981
• Yamaha XS650SE Special, U.S. 1979-1982
• Yamaha XS650 Custom, U.K. 1979-1982

Book Excerpt: 1970-1983 Yamaha 650, XS650, TX650 Twins Repair Manual GENERAL DESCRIPTION

The engine fitted to the Yamaha 650 twins is a single overhead camshaft vertical twin. A 360 degree crankshaft is carried in three main bearings. A centrally placed sprocket drives the single overhead camshaft, by way of a single-row chain which runs in a tunnel between the cylinders. The various engine castings are of light alloy, the block being fitted with dry steel liners. The crankcases, which house the crankshaft assembly and gearbox components, separate horizontally to make dismantling easier, and to preserve oil-tightness in the wet sump engine unit. Engine lubrication is provided by a trochoidal oil pump, giving a pressure feed to the main components. The gearbox internals run in the oil bath formed by the lower crankcase half. A multi-plate clutch, mounted on the left-hand side of the unit transmits power from the engine to the gearbox via a gear primary drive. Secondary drive is by way of a heavy roller chain to the rear wheel.

ENGINE REASSEMBLY | FITTING THE CYLINDER HEAD COVER, AUTO-ADVANCE UNIT AND CONTACT BREAKER ASSEMBLY

1. Check that the locating dowels (2 off) are in position over their associated studs, then slide the cylinder head cover into position, having coated the surfaces with gasket compound. Fit the rubber sealing washers to the two outermost studs at each side of the cylinder head. Tighten the nuts and bolts retaining the cylinder head and cover in the order and to the torque settings shown in Fig 1.15.
2. Check the condition of the 'O' rings and oil seals fitted to the contact breaker housing and the auto-advance unit housing. If necessary, renew any worn or damaged items. Grease the lips of the oil seals prior to reassembly. Place the housings into position, and fit the retaining screws.
3. Fit the auto-advance unit drive pin into its hole in the camshaft end, then place the auto-advance unit into position and fit the slotted retaining nut. Tighten the nut using a small parallel punch and a hammer (Note: the auto-advance bobweights should not be in position at this stage).

CUSTOMER REVIEW: I recieved the Service Manual in less time than expected. Also being that this service manual is at a "hard to find" status at all book stores here I greatly appreciated the fact that with this merchant it was easily available and inexpensive. S.K. | Honolulu, HI

Subject: 1970, 1971, 1972, 1973, 1974, 1975, 1976, 1977, 1978, 1979, 1980, 1981, 1982, 1983 Yamaha 650, XS650, TX650 Twins service, maintenance, repair. ISBN-10: 1850109214 | ISBN-13: 9781850109211 | Haynes 341