This Clymer DIY repair manual covers 1979-1982 Honda CB650 four-cylinder models, including:
- Honda CB650, 1979-1982
- Honda CB650C Custom, 1980-1981
- Honda CB650SC Nighthawk, 1982
Note: chapters 1 through 12 contain info on all 1979-1981 CB650-Four models; the supplement at the end of the manual contains info specific to 1982 models which differs from earlier CB650 models.
Book Excerpt: 1979-1982 Honda CB650 Fours Repair Manual
VALVE GUIDE REPLACEMENT
CLUTCH AND TRANSMISSION
When valve guides are worn so that there is excessive stem-to-guide clearance or valve tipping, the guides must be replaced. Replace all, even if only one is worn. This job should only be done by a dealer as special tools are required.
VALVE SEAT RECONDITIONING
This job is best left to a dealer or qualified machine shop. They have special equipment and knowledge for this exacting job. You can still save considerable money by removing the cylinder head and taking the head to the shop for repairs.
Valve lapping is a simple operation which can restore the valve seal without machining, providing the amount of wear or distortion is not too severe.
- Coat the valve seating area in the cylinder head with a lapping compound such as Carborundum or Clover Brand.
- Insert the valve into the cylinder head.
- Wet the suction cup of the lapping stick (Figure 56) and stick it onto the head of the valve. Lap the valve to the seat by rotating the lapping stick in both directions.
Every 5-10 seconds, rotate the valve 180 degrees in the valve seat; continue lapping until the contact surfaces of the valve and the valve seat are a uniform gray. Stop as soon as they are; avoid removing too much material.
- Thoroughly clean the valves and cylinder head in solvent to remove all traces of the grinding compound. Any compound left on the valves or cylinder head will cause damage.
DRIVE SPROCKET: REMOVAL/INSTALLATION
TABLE of CONTENTS:
- Place the bike on the centerstand or place a milk crate or wood block(s) under the engine or frame to support the bike securely.
- Remove the gear shift lever (A, Figure 51) and left-hand rear crankcase cover (B,Figure 51).
- Remove the rear axle nut cotter pin and loosen the axle nut (A, Figure 52).
- Loosen the drive chain adjusters (B, Figure 52) and push the rear wheel forward to allow slack in the drive chain.
- Remove the bolts (A, FIgure 53) securing the drive sprocket and drive sprocket holding plate (B, Figure 53).
- Rotate the drive sprocket holding plate slightly and slide it off the shaft.
- Quick Reference Data
- General Information
- Lubrication, Maintenance and Tune-up
- Clutch and Transmission
- Fuel and Exhaust Systems
- Ignition System
- Front Suspension and Steering
- Rear Suspension
- Suspension Adjustment
- Wiring Diagrams
This manual has been extremely useful to me. I bought a 1979 Honda CB650 this winter and I've been using the manual to restore, renovate and repair it. I've used it for everything, from adjusting the valves to synchronizing the carbs, to adjusting the clutch to removing and replacing the front tire.
The manual has very specific, easy to understand instructions about repairing and tuning the engine, suspension, brakes, electrical system and chassis. The instructions and pictures are easy to find and follow. The tables have all the specifications needed for reassembly.
I also have the factory workshop manual but have found that this Clymer manual is easier to follow and use, it has better instructions and photos and is better organized.
andmdash; David Starr | Pinckney, Michigan
Subject: 1979, 1980, 1981, 1982 Honda CB650 Fours service, maintenance, repair. ISBN-10: 0892873434 | ISBN-13: 9780892873432 | Clymer M336