User manual YAMAHA 20DM SERVICE MANUAL

[. . . ] In addition, the many tips given in this manual will help keep your motorcycle in the best possible condition. If you have any further questions, do not hesitate to contact your Yamaha dealer. The Yamaha team wishes you many safe and pleasant rides. So, remember to put safety first! IMPORTANT MANUAL INFORMATION EAU10151 Particularly important information is distinguished in this manual by the following notations: The Safety Alert Symbol means ATTENTION! [. . . ] Check that the porcelain insulator around the center electrode of the spark plug is a medium-to-light tan (the ideal color when the vehicle is ridden normally). NOTE: If the spark plug shows a distinctly different color, the engine could be operating improperly. Do not attempt to diagnose such problems yourself. Instead, have a Yamaha dealer check the vehicle. To install the spark plug 1. Measure the spark plug gap with a wire thickness gauge and, if necessary, adjust the gap to specification. NOTE: If a torque wrench is not available when installing a spark plug, a good estimate of the correct torque is 1/4­1/2 turn past finger tight. However, the spark plug should be tightened to the specified torque as soon as possible. Spark plug gap Spark plug gap: 0. 6­0. 7 mm (0. 024­0. 028 in) 6-8 PERIODIC MAINTENANCE AND MINOR REPAIR EAU37171 Engine oil The engine oil level should be checked before each ride. In addition, the oil must be changed at the intervals specified in the periodic maintenance and lubrication chart. NOTE: Make sure that the vehicle is positioned straight up when checking the oil level. A slight tilt to the side can result in a false reading. Start the engine, warm it up for several minutes, and then turn it off. Install the sponge material into the air filter element, and then install the air filter element into the air filter case. ECA10480 4. Remove the sponge material from the air filter element. Lightly tap the air filter element to remove most of the dust and dirt, and then blow the remaining dirt out with compressed air on the mesh side as shown. If the air filter element is damaged, replace it. 6. Clean the sponge material with solvent, then squeeze the remaining solvent out, and be sure to let the sponge material dry before installing it into the air filter element. If the sponge material is damaged, replace it. 6 CAUTION: G G Make sure that the air filter element is properly seated in the air filter case. The engine should never be operated without the air filter element installed, otherwise the piston(s) and/or cylinder(s) may become excessively worn. 8. Install the air filter case cover by installing the screws. 6-11 PERIODIC MAINTENANCE AND MINOR REPAIR 9. Check the hose at the bottom of the air filter case for accumulated dust or water, and if necessary, drain it by removing the clamp, and then removing the plug. EAU44730 EAU21370 Checking the engine idling speed The engine idling speed must be checked as follows and, if necessary, adjusted by a Yamaha dealer at the intervals specified in the periodic maintenance and lubrication chart. Start the engine and warm it up for several minutes at 1000­2000 r/min while occasionally revving it to 4000­5000 r/min. Engine idling speed: 1300­1500 r/min Adjusting the throttle cable free play 6 1. Throttle cable free play adjusting nut 10. [. . . ] 3-8 Centerstand and sidestand, checking and lubricating. . . . . . . . . . . . . . . . . . . . . 6-24 Clutch lever. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-5 Clutch lever free play, adjusting . . . . . . . . . . . 6-16 K Key identification number. . . . . . . . . . . . . . . . . . . . . . . . 9-1 Kickstarter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-8 T Tachometer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [. . . ]