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READ THIS MANUAL CAREFULLY! It contains important safety information. OWNER’S MANUAL YFM400NM(C) WARNING This ATV should not be ridden by anyone under 16 years of age. LIT-11626-13-34 5GW-F8199-10...
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Congratulations on your purchase of the Yamaha YFM400N. It represents the result of many years of Yamaha experience in the production of fine sporting, touring, and pace- setting racing machines. With the purchase of this Yamaha, you can now appreciate the high degree of craftsmanship and reliability that have made Yamaha a leader in these fields.
EBU00010 IMPORTANT MANUAL INFORMATION FAILURE TO FOLLOW THE WARNINGS CONTAINED IN THIS MANUAL CAN RESULT IN SERIOUS INJURY OR DEATH. Particularly important information is distinguished in this manual by the following nota- tions: The Safety Alert Symbol means ATTENTION! BECOME ALERT! YOUR SAFETY IS INVOLVED! Failure to follow WARNING instructions could result in severe injury WARNING...
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Please check your local riding laws and regulations before operating this machine. EBU00531 YFM400NM (C) OWNER’S MANUAL AFFIX DEALER 1999 by Yamaha Motor Corporation, U.S.A. LABEL HERE 1st Edition, September 1999 All rights reserved. Any reprinting or unauthorized use without the written...
EBU00014 CONTROL FUNCTIONS....4-1 WARNING Main switch........4-1 Indicates a potential hazard that could re- Indicator lights........4-2 sult in serious injury or death. Oil temperature indicator light checking method......4-3 Fuel gauge ........4-4 CONTENTS Handlebar switches .......4-5 Throttle lever ........4-6 Speed limiter ........4-7 LOCATION OF THE WARNING Front brake lever ......4-8 AND SPECIFICATION LABELS ..1-1...
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Front shock absorber OPERATION........6-1 adjustment ......... 4-17 Starting a cold engine ....6-1 Rear shock absorber Starting a warm engine....6-3 adjustment ......... 4-18 Warming up........6-3 Auxiliary DC jack......4-19 Reverse knob operation and reverse driving ......6-4 PRE-OPERATION CHECKS ..... 5-1 Shifting..........6-5 Front and rear brakes ....
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Crossing through shallow Front brake fluid level water ...........7-34 inspection........8-20 Riding over rough terrain....7-36 Brake fluid replacement ....8-21 Sliding and skidding....7-38 Rear brake pedal and lever What to do if.........7-40 adjustment........8-23 What to do ........7-40 Clutch adjustment ......8-26 Cable inspection and PERIODIC MAINTENANCE AND lubrication ........8-27 ADJUSTMENT .........8-1...
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CLEANING AND STORAGE.... 9-1 A. Cleaning ........9-1 B. Storage ........9-3 SPECIFICATIONS......10-1 NOISE REGULATION ....11-1 MAINTENANCE RECORD ..... 12-1 ATV LIMITED WARRANTY ... 13-1 YAMAHA EXTENDED SERVICE (Y.E.S.) ..........14-1...
EBU00464 LOCATION OF THE WARNING AND SPECIFICATION LABELS...
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Never remove any labels from your ATV. If a label becomes difficult to read or comes off, a replacement label is available from WARNING your Yamaha dealer. IMPROPER TIRE PRESSURE OR OVERLOADING CAN CAUSE LOSS OF CONTROL. LOSS OF CONTROL CAN RESULT IN SEVERE INJURY OR DEATH.
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WARNING LOAD LIMIT NEVER 80kg (176lbs) sit here. 5FU-F4897-00...
EBU00017 SAFETY INFORMATION AN ATV IS NOT A TOY AND CAN BE HAZARDOUS TO OPERATE. An ATV handles differ- ently from other vehicles including motorcycles and cars. A collision or rollover can occur quickly, even during routine maneuvers such as turning and riding on hills or over obsta- cles, if you fail to take proper precautions.
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● Always avoid operating an ATV on any paved surfaces, including sidewalks, drive- ways, parking lots and streets. ● Never operate an ATV on any public street, road or highway, even a dirt or gravel one. Never operate an ATV without wearing an approved motorcycle helmet that fits prop- ●...
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● Always follow proper procedures for turning as described in this manual. Practice turning at low speeds before attempting to turn at faster speeds. Do not turn at exces- sive speed. Never operate the ATV on hills too steep for the ATV or for your abilities. Practice on ●...
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Always use proper procedures if you stall or roll backwards when climbing a hill. To ● avoid stalling, use proper gear and maintain a steady speed when climbing a hill. If you stall or roll backwards, follow the special procedure for braking described in this manual.
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● Always use the size and type tires specified in this manual. Always maintain proper tire pressure as described in this manual. Never modify an ATV through improper installation or use of accessories. ● Never exceed the stated load capacity for an ATV. Cargo should be properly distribut- ●...
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WARNING When transporting the machine in an- other vehicle, be sure it is kept upright POTENTIAL HAZARD and that the fuel cock is in the “OFF” Improper handling of gasoline. position. Otherwise, fuel may leak out WHAT CAN HAPPEN of the carburetor or fuel tank. Gasoline can catch fire and you could be WHAT CAN HAPPEN burned.
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WARNING POTENTIAL HAZARD Starting or running the engine in a closed area. WHAT CAN HAPPEN Exhaust fumes are poisonous and may cause loss of consciousness and death within a short time. HOW TO AVOID THE HAZARD Always operate your machine in an area with adequate ventilation.
This number can be used for order- sistance when ordering spare parts from a ing a new key. Yamaha dealer or for reference in case the vehicle is stolen. 1. KEY IDENTIFICATION NUMBER: 2. VEHICLE IDENTIFICATION NUMBER: 1.
Record the information on this label in the space provided. This information will be needed to order spare parts from your Yamaha dealer. 1. Vehicle identification number NOTE: The vehicle identification number is used 1. Model label...
EBU00039 CONTROL FUNCTIONS WARNING Indicates a potential hazard that could re- sult in serious injury or death. EBU00041 Main switch Functions of the respective switch posi- tions are as follows: Engine can be started only at this position and the headlight and taillight come on when the light switch is on.
EBU00043 EBU00047 Indicator lights Oil temperature indicator light “OIL TEMP” When the oil temperature reaches a speci- fied level, this light comes on to warn that the engine oil temperature is too hot. If the light comes on during operation, stop the engine as soon as it is safe to do so and al- low the engine to cool down for about 10 minutes.
EBU00052 Fuel gauge The fuel gauge indicates the amount of fuel in the fuel tank. When the needle reaches the red line, refill the tank at the first opportunity. 1. Fuel gauge NOTE: If the machine runs out of fuel, move the fuel cock lever to the “RES”...
EBU00053 EBU00055* Handlebar switches Start switch “ ” The starter motor cranks the engine when this switch is pushed. CAUTION: See starting instructions prior to starting engine. (see page 6-1 for details) EBU00058* Lights switch “LIGHTS” Turn the switch to “ ”...
Check the operation of the throttle lever before you start the engine. If it does not work smoothly, check for the cause. Correct the problem before riding the ATV. Consult a Yamaha dealer if you can’t find or solve the problem yourself. 1. Throttle lever...
EBU00066 Speed limiter WARNING The speed limiter keeps the throttle from POTENTIAL HAZARD fully opening, even when the throttle lever Improper adjustment of the speed limit- is pushed to the maximum. Screwing in er and throttle. the adjuster limits the maximum engine WHAT CAN HAPPEN power available and decreases the maxi- The throttle cable could be damaged.
EBU00070 Front brake lever The front brake lever is located on the right handlebar. Pull it toward the handlebar to apply the front brake. 1. Rear brake pedal 1. Front brake lever EBU00073 Rear brake pedal and lever The brake pedal is located on the right side of the machine and the brake lever is locat- ed on the left handlebar.
EBU00074 Parking brake WARNING Use the parking brake when you have to POTENTIAL HAZARD start the engine or park the machine, espe- Improper use of the parking brake. cially on a slope. Apply the rear brake lever WHAT CAN HAPPEN and push down the lock plate to apply the The ATV could start moving unexpect- parking brake.
EBU00084 EBU00088* Shift pedal Reverse knob This machine is equipped with a constant- The reverse knob is used to shift into re- mesh 5-speed forward and 1-speed re- verse gear. verse transmission. The shift pedal is lo- Refer to section “Reverse knob operation cated on the left side of the engine.
EBU00590 Recoil starter WARNING Firmly grasp the handle and pull slightly POTENTIAL HAZARD until engagement can be felt. Then pull Starting the engine in gear and/or start- forcefully, being careful not to pull the rope ing the engine without setting the park- all the way out.
EBU00093 Fuel cock The fuel cock supplies fuel from the fuel tank to the carburetor. The fuel cock has three positions. OFF: With the lever in this position fuel will not flow. Always turn the lever to this position when the engine is not running.
EBU00095 Starter (choke) “ ” Starting a cold engine requires a richer air- fuel mixture. A separate starter circuit sup- plies this mixture. Move in direction to turn on the starter (choke). Move in direction to turn off the starter (choke).
EBU00567 Seat To remove the seat, pull the seat lock lever upward and pull up the seat at the rear. 1. Seat lock lever To install the seat, insert the projections on the front of the seat into the seat holders and push down on the seat at the rear.
EBU00581 EBU00582 Storage box Front carrier Maximum load limit: 2 kg (4.4 lb) Maximum load limit: 40 kg (88 lb) CAUTION: EBU00583 To protect from damage, do not put metal Rear carrier products, like tools or sharply edged prod- Maximum load limit: 80 kg (176 lb) ucts directly in the storage box.
EBU00635 Front shock absorber adjustment Standard position: B The spring preload can be adjusted to suit A - Minimum (Soft) the rider’s weight and riding conditions. E - Maximum (Hard) Adjust the spring preload as follows: To increase the spring preload, turn the ad- WARNING juster in direction POTENTIAL HAZARD...
EBU00634 Rear shock absorber adjustment Standard position: B The spring preload can be adjusted to suit A - Minimum (Soft) the rider’s weight and riding conditions. E - Maximum (Hard) Adjust the spring preload as follows: To increase the spring preload, turn the ad- juster in direction To decrease the spring preload, turn the adjuster in direction...
EBU00631* Auxiliary DC jack The auxiliary DC jack is located at the front right side of the ATV. The auxiliary jack can be used for suitable work lights, radios, etc. The auxiliary jack can only be used when the main switch is in the “ON” position. 1.
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CAUTION: Do not use accessories requiring more ● than the above maximum capacity. This may overload the circuit and cause a fuse to blow. ● If accessories are used without the en- gine running or with the headlight turned on, the battery will lose its charge and engine starting may be- come difficult.
PRE-OPERATION CHECKS Before using this machine, check the following points: ITEM ROUTINE PAGE • Check operation, free play, fluid level and fluid leakage. Front brake 5-3 ~ 5-4, • Fill with DOT 4 (or DOT 3) brake fluid if necessary. 8-19 ~ 8-25 Rear brake •...
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WARNING POTENTIAL HAZARD Failure to inspect the ATV before oper- ating. Failure to properly maintain the ATV. WHAT CAN HAPPEN Increases the possibility of an accident or equipment damage. HOW TO AVOID THE HAZARD Always inspect your ATV each time you use it to make sure the ATV is in safe op- erating condition.
They should move smooth- is any leakage, the brake system ly and there should be a firm feeling should be inspected by a Yamaha when the brake is applied. If not, have dealer. the machine inspected by a Yamaha 4.
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Always check the brakes at the start of every ride. Do not ride the ATV if you find any problem with the brakes. If a problem cannot be corrected by the ad- justment procedures provided in this manual, have the ATV inspected by a Yamaha dealer.
15 L (3.3 Imp gal, 4.0 US gal) formance problems. Reserve: 4.0 L (0.9 Imp gal, 1.1 US gal) Your Yamaha engine has been designed to use regular unleaded gasoline with a pump octane number ([R+M]/2) of 86 or higher, or research octane number of 91 or higher.
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WARNING POTENTIAL HAZARD Improper care when refueling. WHAT CAN HAPPEN Fuel can spill, which can cause a fire and severe injury. Fuel expands when it heats up. If the fuel tank is overfilled, fuel could spill out due to heat from the engine or the sun. HOW TO AVOID THE HAZARD Do not overfill the fuel tank.
EBU00484 Engine oil CAUTION: Make sure the engine oil is at the specified Be sure to use motor oils that do not con- level. Add oil as necessary. (See page 8-5 ~ tain anti-friction modifiers. 8-8.) Passenger car motor oils (often labeled “Energy Conserving”) contain anti-friction Recommended oil: additives which will cause clutch and/or...
Take the ma- NOTE: chine to a Yamaha dealer or refer to the Ser- GL-4 is a quality and additive rating, GL-5 vice Manual for correct tightening torque. or GL-6 rated hypoid gear oils may also be...
HOW TO AVOID THE HAZARD 1. The tires listed below have been ap- proved by Yamaha Motor Co., Ltd. for this model. Other tire combinations are not recommended. Manufacturer Size...
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2. The tires should be set to the recom- 4. Use no more than the following pres- mended pressure: sures when seating the tire beads. Recommended tire pressure Front 250 kPa (2.5 kgf/cm , 36 psi) ● Front 25 kPa (0.25 kgf/cm , 3.6 psi) Rear 250 kPa (2.5 kgf/cm , 36 psi)
EBU00159 How to measure tire pressure Use the low-pressure tire gauge. NOTE: The low-pressure tire gauge is included as standard equipment. Make two measure- ments of the tire pressure and use the sec- ond reading. Dust or dirt in the gauge could cause the first reading to be incor- rect.
2. Turn the fuel cock to “ON”. there is a control or function you do not 3. Turn the main switch to “ON” and the understand, ask your Yamaha dealer. engine stop switch to “ ”. 4. Shift the transmission into neutral.
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If the light does not come on, ask a tion. Yamaha dealer to inspect it. The engine can be started in any gear ● if the rear brake lever is applied. How- ever, it is recommended to shift into neutral before starting the engine.
NOTE: CAUTION: If the engine fails to start, release the ● See the “Engine break-in” section prior to start switch, then push the start switch operating engine for the first time. again. Pause a few seconds before the next attempt. Each cranking should be as short as possible to preserve bat- EBU00180 tery energy.
If the light does not come on, CAUTION: ask a Yamaha dealer to inspect the machine. Before shifting, stop the machine and re- 4. Check behind you for people or obsta- turn the throttle lever to its closed posi- cles, then release the rear brake lever.
EBU00201 Shifting CAUTION: This model has a 5-speed forward and 1- Do not coast for long periods with the en- speed reverse transmission with centrifu- gine off, and do not tow the machine a gal automatic clutch. The transmission al- long distance.
EBU00207 4. Once the machine has attained ade- To decelerate quate speed, release the throttle lever. When slowing down or stopping, release 5. Shift into second gear and release the the throttle and apply the brakes smoothly shift pedal. and evenly. As you slow down, shift to a 6.
Because the If any abnormality is noticed during this engine is brand new, you must not put an period, consult a Yamaha dealer. excessive load on it for the first several 1. 0 ~ 10 hours: hours of running.
EBU00211 2. 10 ~ 20 hours: Parking Avoid prolonged operation above 3/4 When parking, stop the engine and shift throttle. Rev the machine freely into neutral. Turn the fuel cock to “OFF” through the gears but do not use full and apply the parking brake.
EBU00219 Parking on a slope 1. Bring the machine to a stop by apply- ing the brakes in low gear. WARNING 2. Stop the engine. POTENTIAL HAZARD 3. With the rear brake lever and pedal ap- Parking on a hill or other incline. plied, apply the parking brake and WHAT CAN HAPPEN slowly release the rear brake pedal.
Choose only accessories designed for ● not limited to) a heavy or bulky object at- your ATV. Your Yamaha dealer has a va- tached to the handlebars which could riety of genuine Yamaha accessories. make steering difficult, an accessory that...
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EBU00588 Loading Do not exceed the maximum tongue ● Cargo or a trailer can change the stability weight. You can measure tongue weight and handling of an ATV. with a bathroom scale. Put the tongue of You must use common sense and good the loaded trailer on the scale with the judgment when carrying cargo or towing a tongue at hitch height.
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Ride more slowly than you would with- ● WARNING out a load. The more weight you carry, POTENTIAL HAZARD the slower you should go. Although con- Overloading this ATV or carrying or ditions vary, it is good practice not to ex- towing cargo improperly.
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EBU00543 WARNING Indicates a potential hazard that could result in serious injury or death. 6-13...
WARNING Indicates a potential hazard that could re- sult in serious injury or death. GETTING TO KNOW YOUR ATV achieve the skill necessary to enjoy riding This ATV is mainly for utility use, but may safely. Before you begin to ride, be sure also be used for recreation.
Beginning and inexperienced operators Get training if you are inexperienced. should complete the certified training Beginners should get training from a certi- course offered by Yamaha. They should fied instructor. then regularly practice the skills learned Become familiar with this ATV at slow...
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Not recommended for children under 16 years of age. WARNING POTENTIAL HAZARD Failure to follow the age recommenda- tions for this ATV. WHAT CAN HAPPEN Use by children of ATVs that are not rec- ommended for their age can lead to se- vere injury or death of the child.
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This machine is designed to carry operator and cargo only - passengers prohibited. WARNING POTENTIAL HAZARD Carrying a passenger on this ATV. WHAT CAN HAPPEN Greatly reduces your ability to balance and control this ATV. Could cause an ac- cident, resulting in harm to you and/or your passenger.
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Apparel Operating without protective clothing WARNING increases your chances of severe injury in the event of an accident. POTENTIAL HAZARD HOW TO AVOID THE HAZARD Operating this ATV without wearing an Always wear an approved motorcycle approved motorcycle helmet, eye pro- helmet that fits properly.
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Do not operate after consuming alcohol or WARNING drugs. POTENTIAL HAZARD Operator’s performance capability is re- Operating this ATV after consuming al- duced by the influence of alcohol or drugs. cohol or drugs. WHAT CAN HAPPEN Could seriously affect your judgment. Could cause you to react more slowly.
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Pre-operation checks WARNING Always perform the pre-operation checks POTENTIAL HAZARD listed on page 5-1 before riding for safety Operating this ATV with improper tires, and proper care of the machine. or with improper or uneven tire pres- WARNING sure. POTENTIAL HAZARD WHAT CAN HAPPEN Failure to inspect the ATV before oper- Use of improper tires on this ATV, or op-...
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Speed limiter WARNING For riders inexperienced with this model, Indicates a potential hazard that could re- this model is equipped with a speed limiter sult in serious injury or death. in the throttle lever housing. The speed Do not operate at speeds too fast for your limiter limits the power and top speed of skills or the conditions.
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Loading and accessories WARNING Use extra caution when riding the machine POTENTIAL HAZARD with additional loads, such as accessories Overloading this ATV or carrying or or cargo. The machine’s handling may be towing cargo improperly. adversely affected. Reduce your speed WHAT CAN HAPPEN when adding additional loads.
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During operation WARNING Always keep your feet on the footboards POTENTIAL HAZARD during operation. Otherwise your feet may Removing hands from handlebars or contact the rear wheels. feet from footboards during operation. WHAT CAN HAPPEN Removing even one hand or foot can re- duce your ability to control the ATV or could cause you to lose your balance and fall off of the ATV.
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Avoid wheelies and jumping. You may lose control of the machine or overturn. WARNING POTENTIAL HAZARD Attempting wheelies, jumps, and other stunts. WHAT CAN HAPPEN Increases the chance of an accident, in- cluding an overturn. HOW TO AVOID THE HAZARD Never attempt stunts, such as wheelies or jumps.
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Never modify this ATV through improp- er installation or use of accessories. All parts and accessories added to this ve- hicle should be genuine Yamaha or equivalent components designed for use on this ATV and should be installed and used according to instructions. If you have questions, consult an autho- rized ATV dealer.
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Exhaust system The exhaust system on the machine is very hot during and following operation. To prevent burns, avoid touching the exhaust system. Park the machine in a place where pedestrians or children are not likely to touch it. WARNING POTENTIAL HAZARD Hot exhaust system.
BE CAREFUL WHERE YOU RIDE This machine is designed for off-road use only. Riding on paved surfaces can cause loss of control. WARNING POTENTIAL HAZARD Operating this ATV on paved surfaces. WHAT CAN HAPPEN ATVs are designed for off-road use only. Paved surfaces may seriously affect handling and control of the ATV, and may cause the vehicle to go out of con-...
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Do not ride on any public road, street, or highway. Riding on public roads can result in colli- sions with other vehicles. WARNING POTENTIAL HAZARD Operating this ATV on public streets, roads or highways. WHAT CAN HAPPEN You can collide with another vehicle. HOW TO AVOID THE HAZARD Never operate this ATV on any public street, road or highway, even a dirt or...
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Know the terrain where you ride. Ride cau- tiously in unfamiliar areas. Stay alert for holes, rocks, or roots in the terrain, and other hidden hazards which may cause the machine to upset. WARNING POTENTIAL HAZARD Failure to use extra care when operating this ATV on unfamiliar terrain.
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WARNING POTENTIAL HAZARD Failure to use extra care when operating on excessively rough, slippery or loose terrain. WHAT CAN HAPPEN Could cause loss of traction or vehicle control, which could result in an acci- dent, including an overturn. HOW TO AVOID THE HAZARD Do not operate on excessively rough, slippery or loose terrain until you have learned and practiced the skills neces-...
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When riding in an area where you might WHAT CAN HAPPEN not easily be seen, such as desert terrain, You could be in a collision. You could be mount a caution flag on the machine. DO injured. NOT use the flag pole bracket as a trailer HOW TO AVOID THE HAZARD hitch.
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Select a large, flat area off-road to become With the engine idling, lift the shift pedal to familiar with your ATV. Make sure that this the 1st gear position and then release the area is free of obstacles and other riders. parking brake.
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WARNING CAUTION: Do not shift gears without releasing the POTENTIAL HAZARD throttle. Damage to the engine or drive Engaging a lower gear when the engine train may occur. speed is too high. WHAT CAN HAPPEN When slowing down or stopping, release The wheels could stop rotating.
TURNING YOUR ATV HOW TO AVOID THE HAZARD To achieve maximum traction while riding Always follow proper procedures for off-road, the two rear wheels are mounted turning as described in this Owner’s solidly on one axle and turn together at the Manual.
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Once you have learned this technique you should be able to perform it at higher speeds or in tighter curves. Improper riding procedures such as abrupt throttle changes, excessive braking, incor- rect body movements, or too much speed for the sharpness of the turn may cause the ATV to tip.
CLIMBING UPHILL HOW TO AVOID THE HAZARD Use proper riding techniques to avoid ve- Never operate the ATV on hills too hicle overturns on hills. Be sure that you steep for the ATV or for your abilities. can maneuver your ATV well on flat Practice on smaller hills before attempt- ground before attempting any incline and ing large hills.
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WARNING An obstacle, a sharp drop, or another vehicle or person could be on the other POTENTIAL HAZARD side of the hill. Climbing hills improperly. WHAT CAN HAPPEN Could cause loss of control or cause the ATV to overturn. HOW TO AVOID THE HAZARD Always follow proper procedures for climbing hills as described in this Own- er’s Manual.
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If you are climbing a hill and you find that When crossing the side of a hill: you have not properly judged your ability Always follow proper procedures as de- to make it to the top, you should turn the scribed in the Owner’s Manual.
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If your ATV has stalled or stopped and you WARNING believe you can continue up the hill, restart POTENTIAL HAZARD carefully to make sure you do not lift the Stalling, rolling backwards or improper- front wheels which could cause you to lose ly dismounting while climbing a hill.
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Dismount on uphill side or to a side if pointed straight uphill. Turn the ATV around and remount, following the pro- cedure described in the Owner’s Manu- 7-29...
RIDING DOWNHILL WARNING When riding your ATV downhill, shift your POTENTIAL HAZARD weight as far to the rear and uphill side of Going down a hill improperly. the ATV as possible. Move back on the seat WHAT CAN HAPPEN and sit with your arms straight. Choose a Could cause loss of control or cause low gear which will allow the engine com- ATV to overturn.
CROSSING A SLOPE If your ATV does begin to tip over, gradual- Traversing a sloping surface on your ATV ly steer in the downhill direction if there requires you to properly position your are no obstacles in your path. As you re- weight to maintain proper balance.
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When crossing the side of a hill: Always follow proper procedures as de- scribed in the Owner’s Manual. Avoid hills with excessively slippery or loose surfaces. Shift your weight to the uphill side of the ATV. 7-33...
CROSSING THROUGH SHALLOW WATER Remember that wet brakes may have The ATV can be used to cross slow mov- reduced stopping ability. Test your ing, shallow water of up to a maximum of brakes after leaving water. If necessary, 35 cm (14 inches) in depth. Before entering apply them several times to let friction the water, choose your path carefully.
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Test your brakes after leaving the water. CAUTION: Do not continue to ride your ATV without After riding your ATV in water, be sure to verifying that you have regained proper drain the trapped water by removing the braking ability. check hose at the bottom of the air filter case.
RIDING OVER ROUGH TERRAIN WARNING Riding over rough terrain should be done POTENTIAL HAZARD with caution. Look out for obstacles which Improperly operating over obstacles. could cause damage to the ATV or could WHAT CAN HAPPEN lead to an upset or accident. Be sure to Could cause loss of control or a colli- keep your feet firmly mounted on the foot- sion.
SLIDING AND SKIDDING If the rear wheels of your ATV start to slide Care should be used when riding on loose sideways, control can usually be regained or slippery surfaces since the ATV may (if there is room to do so) by steering in the slide.
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With practice, over a period of time, skill at WARNING controlled sliding can be developed. The POTENTIAL HAZARD terrain should be chosen carefully before Skidding or sliding improperly. attempting such maneuvers, since both WHAT CAN HAPPEN stability and control are reduced. Bear in You may lose control of this ATV.
WHAT TO DO IF ... ● If your ATV starts to slide sideways: This section is designed to be a reference Steer in the direction of the slide if you guide only. Be sure to read each section on have the room. riding techniques completely.
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If your ATV is traversing a sloping sur- ● face: Be sure to ride with your weight posi- tioned towards the uphill side of the ATV to maintain proper balance. If the ATV starts to tip, steer down the hill (if there are no obstacles in your way) to regain balance.
EBU00515 PERIODIC MAINTENANCE AND Have a Yamaha dealer perform service if ADJUSTMENT you are not familiar with machine ser- vice. Periodic inspection, adjustment and lubri- cation will keep your machine in the safest and most efficient condition possible. EBU00535 Safety is an obligation of the machine Owner’s manual and tool kit...
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If you do not have a torque wrench avail- you have questions, consult an autho- able during a service operation requiring rized Yamaha ATV dealer. one, take your machine to a Yamaha deal- er to check the torque settings and adjust them as necessary.
EBU00261 PERIODIC MAINTENANCE/LUBRICATION INITIAL EVERY ITEM ROUTINE month months months months year • Check valve clearance. Valves* • Adjust if necessary. • Check condition. Spark plug • Adjust gap and clean. • Replace if necessary. • Clean. Every 20~40 hours Air filter •...
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Drive shaft universal joint* • Lubricate. • Check all chassis fittings and fasteners. Fittings and Fasteners* • Correct if necessary. * It is recommended that these items be serviced by a Yamaha dealer. NOTE: Brake fluid replacement: 1. When disassembling the master cylin- der or caliper cylinder, replace the brake fluid.
EBU00268 Engine oil d. Remove the dipstick and inspect the 1. Engine oil level measurement oil level. a. Place the machine on a level place. e. The oil level should be between the b. Warm up the engine for several min- maximum and minimum marks.
2. Engine oil replacement and oil filter el- ement cleaning a. Place the machine on a level place. b. Warm up the engine for several min- utes and stop it. c. Place a container under the engine. d. Remove the dipstick and drain plug to drain the oil.
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f. Clean the oil strainer and oil filter with Tightening torque: solvent. Drain plug (engine): g. Inspect the O-ring and replace if dam- 32 Nm (3.2 m·kg, 23 ft·lb) aged. Filter cover bolt: h. Reinstall the oil filter, O-ring, oil filter 10 Nm (1.0 m·kg, 7.2 ft·lb) cover, oil strainer and drain plug.
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j. Warm up the engine for several min- utes at idle speed. Check for oil leak- age while warming up. CAUTION: If oil leakage is found, stop the engine im- mediately and check for the cause. 3. Oil pressure check a.
EBU00466 Final gear oil 1. Final gear oil measurement a. Place the machine on a level place. b. Remove the oil filler bolt and check the oil level. It should be up to the brim of the hole. If the level is low, add oil to raise it to the proper level.
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b. Place the machine on a level place. f. Fill the final gear case with oil. c. Place a container under the final gear Recommended oil: case. SAE 80 API “GL-4” Hypoid gear oil d. Remove the oil filler bolt and the drain Oil quantity: bolt to drain the oil.
0.6 ~ 0.7 mm (0.024 ~ 0.028 in) der. Do not attempt to diagnose such prob- lems yourself. Instead, take the machine to a Yamaha dealer. You should periodically remove and inspect the spark plug because heat and deposits will cause the spark plug to slowly break down and erode.
EBU00589* When installing the spark plug, always Air filter cleaning clean the gasket surface and use a new NOTE: gasket. Wipe off any grime from the There is a check hose at the bottom of the threads and tighten to the specified torque. air filter case.
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4. Separate the foam cover from the air filter element. 5. Tap the element lightly to remove most of the dust and dirt. Blow out the remaining dirt with compressed air. If the element is damaged, replace it. 6. Wash the foam cover gently but thor- oughly in water or solvent.
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NOTE: CAUTION: The air filter element should be cleaned ev- Do not twist the foam filter when ● ery 20 ~ 40 hours. It should be cleaned squeezing it. more often if the machine is operated in ● Do not add oil to the foam filter. extremely dusty areas.
EBU00459* Spark arrester cleaning 2. Start the engine and rev it up approxi- Select a well-ventilated area free of com- mately twenty times while momen- bustible materials and make sure the ex- tarily creating exhaust system back haust and muffler are cool. pressure by blocking the end of the 1.
CAUTION: Could start a fire. The carburetor was set at the Yamaha fac- HOW TO AVOID THE HAZARD tory after many tests. If the settings are When cleaning the spark arrester: disturbed by someone without sufficient...
EBU00301 Idle speed adjustment NOTE: A diagnostic tachometer must be used for this procedure. 1. Start the engine and warm it up for a few minutes at approximately 1,000 to 2,000 r/min. Occasionally rev the en- gine to 4,000 to 5,000 r/min. The en- gine is warm when it quickly responds 1.
This adjustment however, should be left to a 1. Loosen the locknut. professional Yamaha service technician. 2. Turn the adjusting bolt until the throt- tle lever free play is 3 ~ 5 mm (0.12 ~ 0.20 in).
Apply the rear brake and check the posi- tion of the indicator. If the indicator reach- es the wear limit line, ask a Yamaha dealer to replace shoes as a set. 1. Wear indicator (× 2) a. Wear limit: 1mm (0.04 in) 1.
EBU00315* Front brake fluid level inspection Insufficient brake fluid may let air enter the brake system, possibly causing the brakes LOWER to become ineffective. Before riding, check that the brake fluid is above the lower level and replenish when necessary. Observe these precautions: 1.
Yamaha service 6. Have a Yamaha dealer check the personnel. cause if the brake fluid level goes 2. Have a Yamaha dealer replace the fol- down. lowing components during periodic maintenance or when they are dam- aged or leaking.
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Make sure the brakes do not drag. ● ● Make sure the brakes are not spongy. All air must be bled from the brake system. Replacement of brake components re- quires professional knowledge. These procedures should be performed by a Yamaha dealer. 8-22...
EBU00329 Rear brake pedal and lever adjustment b. Turn the adjusting nut on the brake 1. Brake pedal free play adjustment rod until free play is 20 ~ 30 mm (0.8 ~ a. Fully loosen the adjusting nut on the 1.18 in).
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2. Brake lever free play adjustment b. Screw in the adjusting nut on brake a. Loosen the locknut and fully turn in cable to provide a gap of 0 ~ 1 mm (0 ~ the adjusting bolt at the brake lever. 0.04 in) between the lever and the pin.
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2. Adjusting bolt Make sure the brakes do not drag. ● a. 5 ~ 7 mm (0.20 ~ 0.28 in) Replacement of brake components re- d. Tighten the locknut. quires professional knowledge. These procedures should be performed by a Yamaha dealer. 8-25...
EBU00346 Clutch adjustment 3. Tighten the locknut to specification. 1. Loosen the locknut. Tightening torque: 2. Slowly turn the adjusting bolt counter- 15 Nm (1.5 m·kg, 11 ft·lb) clockwise until resistance is felt. Then, turn it 1/8 turn clockwise. NOTE: Turn the adjusting bolt counterclockwise to decrease the clutch free play and turn it clockwise to increase the free play.
Cable inspection and lubrication Lubricate the inner cables and the cable ends. If the cables do not operate smooth- WARNING ly, ask a Yamaha dealer to replace them. POTENTIAL HAZARD Recommended lubricant: Damaged control cables. Yamaha chain and cable lube or...
EBU00373 EBU00376 Wheel removal Wheel installation 1. Elevate the wheel by placing a suitable When installing the wheel, reverse the re- stand under the frame. moval procedure. Pay attention to the fol- 2. Remove the nuts from the wheel. lowing. 3.
If the battery seems to have discharged, consult a Yamaha dealer. CAUTION: Do not try to remove the sealing caps of the battery cells. You may damage the battery.
EBU00385 Battery maintenance HOW TO AVOID THE HAZARD 1. When the machine is not used for a Avoid contact with skin, eyes or cloth- month or longer, remove the battery ing. Always shield eyes when working and store it in a cool, dark place. Com- near batteries.
If a fuse is blown, turn off the main switch and install a new fuse of the specified am- perage. Then turn on the switches. If the fuse immediately blows again, consult a Yamaha dealer. Specified fuse: 1. Main fuse 2. Spare fuse...
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WARNING POTENTIAL HAZARD Using an improper fuse. WHAT CAN HAPPEN An improper fuse can cause damage to the electrical system which could lead to a fire. HOW TO AVOID THE HAZARD Always use a fuse of the specified rat- ing. Never use a material in place of the proper fuse.
EBU00592* Replacing the headlight bulb If the headlight bulb burns out, replace the bulb as follows: 1. Remove the headlight assembly by re- moving the mount screws. 2. Disconnect the coupler. 3. Remove the light unit assembly from the headlight assembly by removing the screw.
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8. Install the headlight assembly and WARNING connect the coupler. POTENTIAL HAZARD 9. Adjust the headlight beam. (Refer to The headlight bulb is hot when it is on page 8-35.) and immediately after it is turned off. WHAT CAN HAPPEN You can be burned, or a fire could start if the bulb touches something flammable.
Although Yamaha machines receive a rigid CAUTION: inspection before shipment from the facto- ry, trouble may occur during operation. It is advisable to have a Yamaha dealer make this adjustment. Any problem in the fuel, compression, or ignition systems can cause poor starting 1.
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WARNING POTENTIAL HAZARD Checking the fuel system while smok- ing or near an open flame. WHAT CAN HAPPEN Fuel can ignite or explode, causing se- vere injury or property damage. HOW TO AVOID THE HAZARD Do not smoke when checking the fuel system.
Supply fuel. No fuel. 2. Compression There is compression. Compression normal. Use the electric starter to see if there is compression. Ask a Yamaha dealer to No compression. inspect. 3. Ignition Wipe clean with dry cloth. Ignition system Spark good. normal.
EBU00419 CLEANING AND STORAGE CAUTION: Excessive water pressure may cause wa- A. CLEANING ter seepage and deterioration of wheel Frequent, thorough cleaning of your ma- bearings, brakes, transmission seals and chine will not only enhance its appearance electrical devices. Many expensive repair but will improve its general performance bills have resulted from improper high and extend the useful life of many compo-...
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6. Clean the seat with a vinyl upholstery WARNING cleaner to keep the cover pliable and POTENTIAL HAZARD glossy. Operation with wet brakes after wash- 7. Automotive type wax may be applied ing. to all painted and chrome plated sur- WHAT CAN HAPPEN faces.
Do not apply NOTE: oil to any rubber parts or the seat cov- Use of fuel stabilizer and conditioner elimi- nates the need to drain the fuel system. Consult a Yamaha dealer if the fuel system needs to be drained instead.
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7. Remove the battery and charge it. Store it in a dry place and recharge it once a month. Do not store the battery in an excessively warm or cold place (less than 0˚C (30˚F) or more than 30˚C (90˚F)). NOTE: Make any necessary repairs before storing the machine.
EBU00428 SPECIFICATIONS MODEL YFM400N Dimension: Overall length 2,007 mm (79.0 in) Overall width 1,125 mm (44.3 in) Overall height 1,172 mm (46.1 in) Seat height 855 mm (33.7 in) Wheel base 1,230 mm (48.4 in) Minimum ground clearance 245 mm (9.65 in) Minimum turning radius 3,000 mm (118.1 in) Basic weight:...
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MODEL YFM400N Engine oil: Type See page 5-7 Quantity: Periodic oil change 2.9 L (2.6 Imp qt, 3.1 US qt) With oil filter replacement 3.0 L (2.6 Imp qt, 3.2 US qt) Total amount 3.5 L (3.1 Imp qt, 3.7 US qt) Final gear oil: Type SAE 80 API “GL-4”...
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MODEL YFM400N Transmission: Primary reduction system Spur gear Primary reduction ratio 76/24 (3.167) Secondary reduction system Shaft drive 28/24 × 24/18 × 33/09 (5.703) Secondary reduction ratio Transmission type Constant mesh 5-speed forward, 1-speed reverse Operation Left foot operation Gear raito: 40/12 (3.333) 34/18 (1.889) 30/22 (1.364)
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MODEL YFM400N Suspension: Front Double wishbone Rear Swingarm (monocross) Shock absorber: Front Coil spring/Oil damper Rear Coil spring/Oil damper Wheel travel: Front wheel travel 150 mm (5.91 in) Rear wheel travel 150 mm (5.91 in) Electrical: Ignition system C.D.I. Generator system A.C.
EBU00430 NOISE REGULATION TAMPERING WITH NOISE CONTROL SYSTEM PROHIBITED: Federal law prohibits the following acts or the causing thereof: (1) The removal or render- ing inoperative by any person other than for purposes of maintenance, repair, or replace- ment of any device or element of design incorporated into any new vehicle for the purpose of noise control prior to its sale or delivery to the ultimate purchaser or while it is in use or (2) the use of the vehicle after such device or element of design has been removed or ren- dered inoperative by any person.
EBU00431 MAINTENANCE RECORD Copies of work orders and/or receipts for parts you purchase and install will be required to document maintenance done in accordance with the warranty. The chart below is printed only as a reminder to you that the maintenance work is required. It is not acceptable proof of maintenance work.
THE ABOVE EXCLUSION MAY NOT APPLY TO YOU. shall be six (6) months from the date of purchase. appropriate owner’s manual; 2. Give notice to an authorized Yamaha ATV dealer of any and all apparent defects within ten (10) days THIS WARRANTY GIVES YOU SPECIFIC LEGAL...
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Attention: Warranty Department 3. Each Yamaha ATV dealer is held responsible for his setup, service and war- ranty repair work. This will ensure that Yamaha Motor Corporation, U.S.A. has an up-to-date registration record in accordance with federal law.
This excellent Y.E.S. plan coverage is only available to dealer to see how comforting uninterrupted factory- Yamaha owners like you, and only while your Yamaha is still backed protection can be. within the Yamaha Limited Warranty period. So visit your authorized Yamaha dealer to get all the facts.
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Y.E.S. costs less within the first 90 days after you buy your Yamaha. See your dealer today! A special note: If visiting your dealer isn’t convenient, contact Yamaha with your Primary ID number (your frame number). We’ll be happy to help you get the Y.E.S. coverage you need.
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EBU00436 WARNING Indicates a potential hazard that could result in serious injury or death. 14-3...
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LOCATE AND READ OWNER'S MANUAL. FOLLOW ALL INSTRUCTIONS AND WARNINGS. (For replacement manual, call 1-800-532-1558) YAMAHA MOTOR CO., LTD. PRINTED ON RECYCLED PAPER PRINTED IN USA 99 · 9 - 4.7 × 1...