Your off-road Yamaha bike goes through a lot and it's only natural that your bike will need repairs and regular maintenance in order to perform at its peak. Keep your 1968 to 1970 Yamaha 250-400cc Piston-Port Motocross Bike performing at its peak by performing basic repairs and simple maintenance procedures yourself. Not only will you save money, you'll learn a lot about your bike which will make you a better rider. The Clymer manual is designed for DIY bike owners with a strong sense of adventure and solid set of wrenches. The book offers detailed descriptions of various bike systems, step-by-step repair instructions, detailed illustrations, exploded engine views and more. This book is a must-have reference guide for any serious rider.
The 1968-1976 Yamaha 250-400cc Piston-Port motocross and off-road bike repair manual by Clymer covers the following dirtbikes:
Book Excerpt: 1968-1976 Yamaha DT1, DT2, DT3, MX250, MX360, RT1, RT2, RT3, DT250, DT360, DT400, YZ250, YZ350, YZ360 Repair Manual
- Yamaha DT1 Series
- Yamaha DT2 Series
- Yamaha DT3 Series
- Yamaha MX250
- Yamaha MX360
- Yamaha RT1 Series
- Yamaha RT2 Series
- Yamaha RT3 Series
- Yamaha DT250
- Yamaha DT360
- Yamaha DT400
- Yamaha YZ250
- Yamaha YZ350
- Yamaha YZ360
ENGINE, TRANSMISSION, AND CLUTCH
It can be seen from the foregoing discussion that the engine cannot receive its lubrication from an oil supply in the crankcase.
Oil splash in the crankcase would be carried into the cylinder with the fuel/ air charge, resulting in high oil consumption and spark plug fouling.
Yamaha 2-stroke engines use one of 2 methods for engine lubrication.
FUEL AND OIL MIXTURE
Some competition models are lubricated by oil premixed with fuel. Sufficient oil is added to the fuel to provide adequate lubrication for the engine under the high speed and load conditions found in competition.
Under low speed and load conditions, however, the engine receives more oil than is necessary, resulting in possible plug fouling.
In addition, oil starvation can occur in prolonged periods during which the engine turns at high speeds with the throttle closed, as when descending a long hill.
These situations do not occur during competition, but could cause problems for machines intended for street use.
This chapter discusses operating principles and maintenance of the ignition, lighting, and charging systems.
FLYWHEEL MAGNETO: OPERATION
A flywheel magneto provides electric power for the ignition and electrical systems of most of the models covered by this manual.
Separate coils within the magneto supply current for ignition, daytime and nighttime operation, and battery charging.
Alternating current produced by the magneto is used for ignition and lights, except for stoplights and turn signals.
A rectifier converts this alternating current into direct current for charging the battery and operating the horn and turn signals. Figure 1 illustrates construction of a typical magneto.
Figure 2 is a circuit diagram of a typical magneto ignition circuit. As the flywheel rotates, permanent magnets attached to the flywheel revolve past the various windings in the magneto, thereby inducing current in the windings.
Clymer repair manuals are the defacto source for DIY motorcycle repair procedures. They are well known for their easy to follow step-by-step repair or rebuild procedures for all components on your bike. A Clymer repair manual is a must have tool to have at your ready so you can keep your bike on the track and save money at the same time.
Subject: 1968, 1969, 1970, 1971, 1972, 1973, 1974, 1975, 1976 Yamaha DT1, DT2, DT3, MX250, MX360, RT1, RT2, RT3, DT250, DT360, DT400, YZ250, YZ350, YZ360 service, maintenance, and repair procedures.
ISBN-10: 0892872764 | ISBN-13: 9780892872763 | Clymer M415