This Haynes repair manual covers Honda C50, C70, and C70 models, including:

Honda C50 1967-1977; C50Z-2 1977-1979; C50Z-Z 1979-1983; C50Z-A (C50L) 1980-1983; C50-C 1982-1984; C50-E 1984-1985. Honda C70 1972-1977; C70Z-2 1977-1979; C70Z-Z 1979-1983; C70-C 1982-1984; C70-E 1984-1986. Honda C90 (CE90) 1967-1977; C90Z-2 1977-1979; C90Z-Z 1979-1983; C90-C 1983-1984; C90-E 1984-1986; C90-G 1986-1993; C90-N 1992-1993; C90-P 1993-1996; C90-T 1996-1903; C90M-F 1985-1986; C90M-G 1986-1993; C90M-N 1992-1993; C90M-P 1993-1996; C90M-T 1996-2003.

Note: the C50LA automatic transmission models ARE NOT covered by this manual.
Book Excerpt: 1967-2003 Honda C50, C70, C90 Repair Manual ENGINE AND TRANSMISSION

ENGINE REASSEMBLY: FITTING THE BEARINGS AND OIL SEALS TO THE CRANKCASES AND CLUTCH COVER

1. Before fitting any of the crankcase bearings make sure that the bearing housings are scrupulously clean and that there are no burrs or lips on the entry to the housings. Press or drive the bearings into the cases using a mandrel or hammer, after first making sure that they are lined up squarely. Warming the crankcases will help when a bearing is particularly tight fit.
2. When the bearings have been driven home, lightly oil them and make sure they revolve smoothly. This is particularly important in the case of the main bearings.
3. Using a soft mandrel, drive the oil seals into their respective housings. Do not use more force than is necessary because the seals damage very easily.
4. Lightly oil all the other moving parts as a prelude to reassembly. This will ensure all working parts are lubricated adequately during the initial start-up of the rebuilt engine.

ENGINE REASSEMBLY: REFITTING THE OIL PUMP

1. Reference to Chapter 3 will fully explain the operation and renovation of the oil pump so that it is ready to fit to the crankcase as a sub-assembly.
2. Smear a very thin film of jointing compound such as Golden Hermatite onto the crankcase face and stick the gasket into position. Do not use excessive amount of jointing compound as serious engine damage can result if any of the oil-ways are blocked.
3. Fit the oil pump into position and secure it with three screws. Check that it is free to rotate.

WHEELS, BRAKES AND TIRES

FINAL DRIVE CHAIN: EXAMINATION AND LUBRICATION

1. The final drive chain is fully enclosed within a chaincase. Periodically, the tension of the chain will need to be adjusted, to compensate for wear. This is accomplished by sliding the rear wheel backwards in the ends of the rear fork, using the drawbolt adjusters provided. The rear wheel spindle nuts must be slackened before the drawbolts can be turned; also the torque arm bolt on the rear brake plate.
2. The chain is in correct adjustment if there is from 1 ? 2 cm free play in the middle of the lower run. An inspection plug in the lower section of the full chaincase permits access to the chain to check whether the tension is correct.
3. Always adjust the chain adjusters an identical amount, otherwise the rear wheel will be thrown out of alignment. If in doubt about the correctness of wheel alignment, use the technique described in Chapter 5, Section 6, paragraph.
4. After a period of running, the chain will require lubrication. Lack of oil will accelerate the rate of wear of both chain and sprockets, leading to harsh transmission. The application of engine oil from an oil can will serve as a satisfactory lubricant, but it is preferable to remove the chain at regular intervals and immerse it in a paraffin bath. This latter type of lubricant achieves better penetration of the chain links and rollers and is less likely to be thrown off when the chain is in motion. An equally effective and less messy alternative is a spray-on lubricant of the aerosol type, such as Castrol chain Lubricant.

Subject: 1967, 1968, 1969, 1970, 1971, 1972, 1973, 1974, 1975, 1976, 1977, 1978, 1979, 1980, 1981, 1982, 1983, 1984, 1985, 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003 Honda C50, C70, C90 service, maintenance, repair. ISBN-10: 1844253759 | ISBN-13: 9781844253753 | Haynes 0324