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  4. BIG BEAR YFM400NN
  5. Owner's Manual

Yamaha BIG BEAR YFM400NN Owner's Manual

Summary of BIG BEAR YFM400NN

  • Page 1

    5gw-f8199-11 lit-11626-14-22 read this manual carefully! It contains important safety information. This atv should not be ridden by anyone under 16 years of age. Warning yfm400nn owner’s manual.

  • Page 3: Introduction

    E ebu00001 introduction 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-set- ting racing machines. With the purchase of this yamaha, you can now appreciate the high degree of cra...

  • Page 4: Important Manual Information

    E 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 i...

  • Page 5: Important Notice

    E ebu00011 important notice this machine is designed and manufactured for off-road use only. It is illegal and unsafe to operate this machine on any public street, road or highway. This machine complies with all applicable off-road noise level and spark arrester laws and regulations in effect at the...

  • Page 6: Contents

    Ebu00014 warning indicates a potential hazard that could result in serious injury or death. Contents location of the warning and specification labels .......1-1 safety information .................2-1 description and machine identification..............................3-1 identification number recor...

  • Page 7

    Front shock absorber adjustment .................................. 4-17 rear shock absorber adjustment .................................. 4-18 auxiliary dc jack.......................... 4-19 pre-operation checks ............. 5-1 front and rear brakes .................... 5-3 fuel.....................

  • Page 8

    Crossing through shallow water ...........................................7-34 riding over rough terrain............7-36 sliding and skidding....................7-38 what to do if.................................7-40 what to do ....................................7-40 periodic maintenance and adjust...

  • Page 9

    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 ........

  • Page 10: Location of The Warning and

    1-1 ebu00464 location of the warning and specification labels.

  • Page 11

    1-2 1 2 3 4 5 6 7 8 9 10 11 12 13 14 read and understand all of the labels on your machine. They contain important in- formation for safe and proper operation of your atv. Never remove any labels from your atv. If a label becomes difficult to read or comes off, a replacement label is available from ...

  • Page 12

    1-3 3 4 5.

  • Page 13

    1-4 6 7.

  • Page 14: Safety Information

    E 2-1 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...

  • Page 15

    2-2 2 2 3 4 5 6 7 8 9 20 22 22 23 24 ● 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 motorcyc...

  • Page 16

    E 2-3 ● 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 smaller hills before...

  • Page 17

    2-4 e ● 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. Dismount on the uphill sid...

  • Page 18

    E 2-5 ● 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- ed...

  • Page 19

    2-6 warning potential hazard improper handling of gasoline. What can happen gasoline can catch fire and you could be burned. How to avoid the hazard always turn off the engine when refuel- ing. Do not refuel right after the engine has been running and is still very hot. Do not spill gasoline on the ...

  • Page 20

    2-7 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..

  • Page 21

    3-1 3 3 3 4 5 6 7 8 9 30 33 33 33 34 ebu00032 description and machine identification 1. Rear carrier 2. Seat 3. Front carrier 4. Rear brake pedal 5. Headlight 6. Fuel cock 7. Recoil starter 8. Rear wheel 9. Shift pedal 10. Front wheel 11. Rear brake lever 12. Parking brake lock plate 13. Starter (ch...

  • Page 22

    3-2 ebu00600 identification number records record the key identification number, vehi- cle identification number and model label information in the spaces provided for as- sistance when ordering spare parts from a yamaha dealer or for reference in case the vehicle is stolen. 1. Key identification nu...

  • Page 23

    3-3 ebu00036 vehicle identification number the vehicle identification number is stamped into the frame. 1. Vehicle identification number note: the vehicle identification number is used to identify your machine. Ebu00038 model label the model label is affixed to the frame. Record the information on t...

  • Page 24: Control Functions

    4-1 ebu00039 control functions warning indicates a potential hazard that could result in serious injury or death. Ebu00041 main switch functions of the respective switch posi- tions are as follows: on: engine can be started only at this position and the headlight and taillight come on when the light...

  • Page 25

    4-2 4 4 4 4 5 6 7 8 9 40 44 44 44 44 ebu00043 indicator lights 1. Reverse indicator light “reverse” 2. Neutral indicator light “neutral” 3. Oil temperature warning light “oil temp” ebu00044 reverse indicator light “reverse” this indicator light comes on when the transmission is in reverse. Ebu00045 ...

  • Page 26

    E 4-3 ebu00733 oil temperature warning light checking method acb-10e turn the main switch to “on” and the engine stop switch to “ ”. Oil temperature warning light does not come on. Oil temperature warning light comes on. Check engine oil temperature. Oil temperature warning light does not come on. E...

  • Page 27

    4-4 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” position. Ap- proximately 4.0 l (0.9 imp ga...

  • Page 28

    4-5 ebu00053 handlebar switches 1. Lights switch 2. Engine stop switch 3. Start switch ebu00054* engine stop switch “ ” make sure that the engine stop switch is in the “ ” position. The engine stop switch controls ignition and can be used at all times to stop the engine, especially in an emergency. ...

  • Page 29

    4-6 ebu00062 throttle lever once the engine is running, movement of the throttle lever will increase the engine speed. Regulate the speed of the machine by varying the throttle position. Because the throttle is spring-loaded, the machine will decelerate, and the engine will return to an idle any tim...

  • Page 30

    4-7 ebu00066 speed limiter the speed limiter keeps the throttle from fully opening, even when the throttle lever is pushed to the maximum. Screwing in the adjuster limits the maximum engine power available and decreases the maxi- mum speed of the atv. 1. Locknut 2. Adjuster a. 12 mm (0.47 in) warnin...

  • Page 31

    4-8 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. 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 ...

  • Page 32

    4-9 ebu00074 parking brake use the parking brake when you have to start the engine or park the machine, espe- cially on a slope. Apply the rear brake lever and push down the lock plate to apply the parking brake. Squeeze the rear brake le- ver to release the parking brake. 1. Lock plate warning pote...

  • Page 33

    4-10 ebu00084 shift pedal this machine is equipped with a constant- mesh 5-speed forward and 1-speed re- verse transmission. The shift pedal is locat- ed on the left side of the engine. Reverse is at the bottom position. Neutral is one posi- tion above reverse. 1. Shift pedal n. Neutral r. Reverse e...

  • Page 34

    4-11 ebu00590 recoil starter firmly grasp the handle and pull slightly until engagement can be felt. Then pull forcefully, being careful not to pull the rope all the way out. 1. Recoil starter warning potential hazard starting the engine in gear and/or start- ing the engine without setting the park-...

  • Page 35

    4-12 ebu00092 fuel tank cap remove the fuel tank cap by turning it counterclockwise. 1. Fuel tank cap.

  • Page 36

    4-13 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. On: with the lever in this position, fuel flows...

  • Page 37

    4-14 ebu00095 starter (choke) “ ” starting a cold engine requires a richer air- fuel mixture. A separate starter circuit sup- plies this mixture. Move in direction a to turn on the starter (choke). Move in direction b to turn off the starter (choke). Refer to “starting a cold engine” for prop- er op...

  • Page 38

    4-15 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. Note: make sure that the seat is securely fitt...

  • Page 39

    4-16 ebu00581 storage box caution: to protect from damage, do not put metal products, like tools or sharply edged prod- ucts directly in the storage box. If they must be stored, wrap them in appropriate cushion material. Ebu00582 front carrier ebu00583 rear carrier maximum load limit: 2 kg (4.4 lb) ...

  • Page 40

    4-17 ebu00635 front shock absorber adjustment the spring preload can be adjusted to suit the rider’s weight and riding conditions. Adjust the spring preload as follows: to increase the spring preload, turn the ad- juster in direction a. To decrease the spring preload, turn the adjuster in direction ...

  • Page 41

    4-18 ebu00634 rear shock absorber adjustment the spring preload can be adjusted to suit the rider’s weight and riding conditions. Adjust the spring preload as follows: to increase the spring preload, turn the ad- juster in direction a. To decrease the spring preload, turn the adjuster in direction b...

  • Page 42

    4-19 ebu00748 auxiliary dc jack the auxiliary dc jack is located at the front right side of the atv. The auxiliary dc jack can be used for suitable work lights, radi- os, etc. The auxiliary dc jack can only be used when the main switch is in the “on” position. 1. Turn the headlight switch to the “of...

  • Page 43

    4-20 caution: ● do not use accessories requiring more than the above maximum capacity. This may overload the circuit and cause the 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 d...

  • Page 44: Pre-Operation Checks

    E 5-1 pre-operation checks before using this machine, check the following points: item routine page front brake • check operation, free play, fluid level and fluid leakage. • fill with dot 4 brake fluid if necessary. 5-3 ~ 5-4, 8-19 ~ 8-25 rear brake • check operation, lever/pedal free play and peda...

  • Page 45

    5-2 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- era...

  • Page 46

    5-3 ebu00478* front and rear brakes 1. Brake levers and brake pedal check for correct free play in the rear brake lever and brake pedal. If the free play is incorrect, adjust it. (see pages 8-23 ~ 8-25.) check operation of the brake levers and pedal. They should move smooth- ly and there should be a...

  • Page 47

    5-4 warning potential hazard riding with improperly operating brakes. What can happen you could lose braking ability, which could lead to an accident. How to avoid the hazard 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...

  • Page 48

    5-5 ebu00126 fuel make sure there is sufficient gasoline in the tank. 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. If knocking or pinging occurs, use a different brand of gasoline...

  • Page 49

    5-6 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...

  • Page 50

    5-7 ebu00484 engine oil make sure the engine oil is at the specified level. Add oil as necessary. (see page 8-5 ~ 8-8.) caution: be sure to use motor oils that do not con- tain anti-friction modifiers. Passenger car motor oils (often labeled “energy conserving”) contain anti-friction additives which...

  • Page 51

    5-8 ebu00493 final gear oil make sure the final gear oil is at the speci- fied level. Add oil as necessary. (see pages 8-9 ~ 8-10 for details.) if desired, an sae 80w90 hypoid gear oil may be used for all conditions. Note: gl-4 is a quality and additive rating, gl-5 or gl-6 rated hypoid gear oils ma...

  • Page 52

    5-9 ebu00153 lights check the headlight and taillight to make sure they are in working condition. Repair as necessary for proper operation. Ebu00155 switches check the operation of the headlight switch, engine stop switch and any other switches. Repair as necessary for proper operation. Ebu00157 tir...

  • Page 53

    5-10 2. The tires should be set to the recom- mended pressure: ● recommended tire pressure front 25 kpa (0.25 kgf/cm 2 , 3.6 psi) rear 25 kpa (0.25 kgf/cm 2 , 3.6 psi) ● check and adjust tire pressures when the tires are cold. ● tire pressures must be equal on both sides. 3. Tire pressure below the ...

  • Page 54

    5-11 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. Set p...

  • Page 55

    5-12 ebu00160 tire wear limit when the tire groove decreases to 3 mm (0.12 in) due to wear, replace the tire. A. 3 mm (0.12 in).

  • Page 56: Operation

    6-1 ebu00161 operation warning indicates a potential hazard that could result in serious injury or death. Ebu00507* starting a cold engine 1. Set the parking brake. 2. Turn the fuel cock to “on”. 3. Turn the main switch to “on” and the engine stop switch to “ ”. 4. Shift the transmission into neutra...

  • Page 57

    6-2 6 6 6 6 6 6 7 8 9 60 66 66 66 66 note: ● when the transmission is in neutral, the neutral indicator light should come on. If the light does not come on, ask a 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 ...

  • Page 58

    6-3 note: ● if the engine fails to start, release the start switch, then push the start switch again. Pause a few seconds before the next attempt. Each cranking should be as short as possible to preserve bat- tery energy. Do not crank the engine more than 10 seconds on each at- tempt. ● if the batte...

  • Page 59

    6-4 ebu00195 reverse knob operation and reverse driving caution: before shifting, stop the machine and re- turn the throttle lever to its closed posi- tion. Otherwise the transmission may be damaged. 1. Bring the machine to a complete stop and return the throttle lever to the closed position with th...

  • Page 60

    6-5 ebu00201 shifting this model has a 5-speed forward and 1-speed reverse transmission with centrif- ugal automatic clutch. The transmission al- lows you to control the amount of power you have available at a given speed or for starting accelerating, climbing, etc. To shift into neutral, return the...

  • Page 61

    6-6 4. Once the machine has attained ade- quate speed, release the throttle lever. 5. Shift into second gear and release the shift pedal. 6. Open the throttle gradually. 7. Follow the same procedure when shifting to the next higher gear. Ebu00207 to decelerate when slowing down or stopping, release ...

  • Page 62

    6-7 ebu00209 engine break-in there is never a more important period in the life of your machine than the period be- tween zero and 20 hours. For this reason, we ask that you carefully read the following material. Because the engine is brand new, you must not put an excessive load on it for the first...

  • Page 63

    6-8 2. 10 ~ 20 hours: avoid prolonged operation above 3/4 throttle. Rev the machine freely through the gears but do not use full throttle at any time. 3. After break-in: avoid prolonged full throttle opera- tion. Vary speeds occasionally. Ebu00211 parking when parking, stop the engine and shift into...

  • Page 64

    6-9 ebu00219 parking on a slope 1. Bring the machine to a stop by apply- ing the brakes in low gear. 2. Stop the engine. 3. With the rear brake lever and pedal ap- plied, apply the parking brake and slowly release the rear brake pedal. Warning potential hazard parking on a hill or other incline. Wha...

  • Page 65

    6-10 ebu00221 accessories and loading ebu00222* accessories accessories can affect the handling and control of your atv. Keep the following in mind when considering an accessory or operating an atv which has accessories. ● choose only accessories designed for your atv. Your yamaha dealer has a va- r...

  • Page 66

    6-11 ebu00588 loading cargo or a trailer can change the stability and handling of an atv. You must use common sense and good judgment when carrying cargo or towing a trailer. Keep the following points in mind: ● never exceed the weight limits shown. An overloaded atv can be unstable. ● do not exceed...

  • Page 67

    6-12 ● ride more slowly than you would with- out a load. The more weight you carry, the slower you should go. Although con- ditions vary, it is good practice not to ex- ceed 2nd gear whenever you are carrying heavier loads or when towing a trailer. ● allow more braking distance. A heavier vehicle ta...

  • Page 68

    E 6-13 ebu00543 warning indicates a potential hazard that could result in serious injury or death..

  • Page 69: Riding

    7-1 e 7-1 riding your atv 7.

  • Page 70

    7-3 warning indicates a potential hazard that could re- sult in serious injury or death. Getting to know your atv this atv is mainly for utility use, but may also be used for recreation. This section, riding your atv, provides general atv riding instructions for recreational riding. The skills and t...

  • Page 71

    7-4 ride with care and good judgement get training if you are inexperienced. Beginners should get training from a certi- fied instructor. Become familiar with this atv at slow speeds first, even if you are an experienced operator. Do not attempt to operate at maximum performance until you are total-...

  • Page 72

    7-5 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. How to avoid the hazard a chi...

  • Page 73

    7-6 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. H...

  • Page 74

    7-7 apparel warning potential hazard operating this atv without wearing an approved motorcycle helmet, eye pro- tection and protective clothing. What can happen operating without an approved motor- cycle helmet increas- es your chances of a severe head injury or death in the event of an accident. Op...

  • Page 75

    7-8 do not operate after consuming alcohol or drugs. Operator’s performance capability is re- duced by the influence of alcohol or drugs. Warning potential hazard operating this atv after consuming al- cohol or drugs. What can happen could seriously affect your judgment. Could cause you to react mor...

  • Page 76

    7-9 pre-operation checks always perform the pre-operation checks listed on page 5-1 before riding for safety and proper care of the machine. 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 a...

  • Page 77

    7-10 warning indicates a potential hazard that could result in serious injury or death. Do not operate at speeds too fast for your skills or the conditions. Speed limiter for riders inexperienced with this model, this model is equipped with a speed limiter in the throttle lever housing. The speed li...

  • Page 78

    7-11 loading and accessories use extra caution when riding the machine with additional loads, such as accessories or cargo. The machine’s handling may be adversely affected. Reduce your speed when adding additional loads. Maximum loading limit ● vehicle loading limit (total weight of cargo, rider an...

  • Page 79

    7-12 during operation always keep your feet on the footboards during operation. Otherwise your feet may contact the rear wheels. Warning potential hazard removing hands from handlebars or feet from footboards during operation. What can happen removing even one hand or foot can re- duce your ability ...

  • Page 80

    7-13 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 jum...

  • Page 81

    7-14 modifications warning potential hazard operating this atv with improper mod- ifications. What can happen improper installation of accessories or modification of this vehicle may cause changes in handling which in some situ- ations could lead to an accident. How to avoid the hazard never modify ...

  • Page 82

    7-15 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. What can happen so...

  • Page 83

    7-16 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 ...

  • Page 84

    7-17 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 operat...

  • Page 85

    7-18 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. What can...

  • Page 86

    7-19 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 r...

  • Page 87

    7-20 when riding in an area where you might not easily be seen, such as desert terrain, mount a caution flag on the machine. Do not use the flag pole bracket as a trailer hitch. Warning potential hazard operating in areas where you might not be seen by other off-road vehicles. Do not ride in areas p...

  • Page 88

    7-21 select a large, flat area off-road to become familiar with your atv. Make sure that this area is free of obstacles and other riders. You should practice control of the throttle, brakes, shifting procedures, and turning techniques in this area before trying more difficult terrain. Always avoid r...

  • Page 89

    7-22 caution: do not shift gears without releasing the throttle. Damage to the engine or drive train may occur. When slowing down or stopping, release the throttle and apply the brakes smoothly and evenly. As you slow down, shift to a lower gear. Be sure that the engine has suf- ficiently slowed bef...

  • Page 90

    7-23 turning your atv to achieve maximum traction while riding off-road, the two rear wheels are mounted solidly on one axle and turn together at the same speed. Therefore, unless the wheel on the inside of the turn is allowed to slip or lose some traction, the atv will resist turning. A special tur...

  • Page 91

    7-24 this procedure should be practiced at slow speed many times in a large off-road area with no obstacles. If an incorrect technique is used, your atv may continue to go straight. If the atv doesn’t turn, come to a stop and then practice the procedure again. If the riding surface is slippery or lo...

  • Page 92

    7-25 climbing uphill use proper riding techniques to avoid ve- hicle overturns on hills. Be sure that you can maneuver your atv well on flat ground before attempting any incline and then practice riding first on gentle slopes. Try more difficult climbs only after you have developed your skill. In al...

  • Page 93

    7-26 warning potential hazard 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. Always check the terrain carefully be- fore you start u...

  • Page 94

    7-27 if you are climbing a hill and you find that you have not properly judged your ability to make it to the top, you should turn the atv around while you still have forward motion (provided you have the room to do so) and go down the hill. Warning potential hazard improperly crossing hills or turn...

  • Page 95

    7-28 if your atv has stalled or stopped and you believe you can continue up the hill, restart carefully to make sure you do not lift the front wheels which could cause you to lose control. If you are unable to continue up the hill, dismount the atv on the uphill side. Physically turn the atv around ...

  • Page 96

    7-29 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- al..

  • Page 97

    7-30 riding downhill when riding your atv downhill, shift your weight as far to the rear and uphill side of the atv as possible. Move back on the seat and sit with your arms straight. Choose a low gear which will allow the engine com- pression to do most of the braking for you. Improper braking may ...

  • Page 98

    7-31.

  • Page 99

    7-32 crossing a slope traversing a sloping surface on your atv requires you to properly position your weight to maintain proper balance. Be sure that you have learned the basic riding skills on flat ground before attempting to cross a sloping surface. Avoid slopes with slippery surfaces or rough ter...

  • Page 100

    7-33 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..

  • Page 101

    7-34 crossing through shallow water the atv can be used to cross slow mov- ing, shallow water of up to a maximum of 35 cm (14 inches) in depth. Before entering the water, choose your path carefully. En- ter where there is no sharp drop off, and avoid rocks or other obstacles which may be slippery or...

  • Page 102

    7-35 test your brakes after leaving the water. Do not continue to ride your atv without verifying that you have regained proper braking ability. Caution: after riding your atv in water, be sure to drain the trapped water by removing the check hose at the bottom of the air filter case. Wash the atv i...

  • Page 103

    7-36 riding over rough terrain riding over rough terrain should be done with caution. Look out for obstacles which could cause damage to the atv or could lead to an upset or accident. Be sure to keep your feet firmly mounted on the foot- boards at all times. Avoid jumping the atv as loss of control ...

  • Page 104

    7-38 sliding and skidding care should be used when riding on loose or slippery surfaces since the atv may slide. If unexpected and uncorrected, slid- ing could lead to an accident. To reduce the tendency for the front wheels to slide in loose or slippery condi- tions, positioning your weight over th...

  • Page 105

    7-39 with practice, over a period of time, skill at controlled sliding can be developed. The terrain should be chosen carefully before attempting such maneuvers, since both stability and control are reduced. Bear in mind that sliding maneuvers should al- ways be avoided on extremely slippery surface...

  • Page 106

    7-40 what to do if ... This section is designed to be a reference guide only. Be sure to read each section on riding techniques completely. What to do ... ● if your atv doesn’t turn when you want it to: bring the atv to a stop and practice the turning maneuvers again. Be sure you are putting your we...

  • Page 107

    7-41 ● 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. If you discover that the atv is ...

  • Page 108: Periodic Maintenance and

    8-1 ebu00515 periodic maintenance and adjustment periodic inspection, adjustment and lubri- cation will keep your machine in the safest and most efficient condition possible. Safety is an obligation of the machine owner. The most important points of ma- chine inspection, adjustment and lubrica- tion...

  • Page 109

    8-2 1. Tool kit 2. Low-pressure tire gauge the service information included in this manual is intended to provide you, the owner, with the necessary information for completing your own preventive mainte- nance and minor repairs. The tools provid- ed in the owner’s tool kit are sufficient for this pu...

  • Page 110

    E 8-3 ebu00261 periodic maintenance/lubrication item routine initial every 1 month 3 months 6 months 6 months 1 year valves* • check valve clearance. • adjust if necessary. Spark plug • check condition. • adjust gap and clean. • replace if necessary. Air filter • clean. • replace if necessary. Every...

  • Page 111

    8-4 e * it is recommended that these items be serviced by a yamaha dealer. Reverse release cable* • check operation. • adjust if necessary. Wheels* • check balance/damage/run out. • repair if necessary. Wheel bearings* • check bearing assembly for looseness/damage. • replace if damaged. Steering sys...

  • Page 112

    8-5 ebu00772 engine oil engine oil level measurement 1. Place the atv on a level surface. 2. Warm up the engine for several min- utes, and then stop it. 3. Remove the dipstick, and then wipe it off with a clean rag. Insert the dipstick in the filler hole without screwing it in. 1. Dipstick note: wai...

  • Page 113

    8-6 engine oil replacement and oil filter ele- ment cleaning 1. Place the atv on a level surface. 2. Warm up the engine for several min- utes, and then stop it. 3. Place a container under the engine. 4. Remove the dipstick, and then remove the drain bolt to drain the oil. Caution: when removing the ...

  • Page 114

    8-7 6. Clean the oil strainer and oil filter with solvent. 7. Check the o-ring for damage and re- place it if necessary. 8. Install the oil filter, o-ring, oil filter cov- er, oil strainer, compression spring and drain bolt. Tighten the drain bolt to the specified torque. Caution: before installing ...

  • Page 115

    8-8 10. 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. Oil pressure check 1. Put a cloth around the cylinder. 2. Slightly loosen the oil gallery bolt in the cyl...

  • Page 116

    8-9 ebu00705 final gear oil final gear oil measurement 1. Place the machine on a level place. 2. 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. Caution: be sure no foreign material enters the ...

  • Page 117

    8-10 2. Place the machine on a level place. 3. Place a container under the final gear case. 4. Remove the oil filler bolt and the drain bolt to drain the oil. 1. Drain bolt 5. Install the drain bolt and tighten to the specified torque. 6. Fill the final gear case with oil. Caution: be sure no foreig...

  • Page 118

    8-11 ebu00286 spark plug inspection the spark plug is an important engine component and is easy to inspect. The condition of the spark plug can indicate the condition of the engine. For example, a very white center electrode porcelain color could indicate an intake air leak or carburetion problem fo...

  • Page 119

    8-12 ebu00589* air filter cleaning note: there is a check hose at the bottom of the air filter case. If dust or water collects in this hose, empty the hose and clean the air filter element and air filter case. 1. Check hose 1. Remove the seat. (refer to page 4-15 for removal and installation proce- ...

  • Page 120

    8-13 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 as shown. If the element is damaged, re- place it. 6. Wash the foam cover gently but thor- oughly in water or solvent. 7. Squee...

  • Page 121

    8-14 caution: ● do not twist the foam filter when squeezing it. ● do not add oil to the foam filter. 8. Inspect the foam cover. If damaged, replace it. 9. Install the foam cover onto the air filter element. 10. Install the air filter assembly and parts removed for access. 1. Air filter element 2. Fo...

  • Page 122

    8-15 ebu00754 spark arrester cleaning select a well-ventilated area free of com- bustible materials and make sure the ex- haust pipe and muffler are cool. 1. Remove the purging bolt. 1. Purging bolt ( × 1) 2. Start the engine and rev it up approxi- mately twenty times while momen- tarily creating ex...

  • Page 123

    8-16 ebu00296 carburetor adjustment the carburetor is a vital part of the engine and requires very sophisticated adjust- ment. Most adjusting should be left to a yamaha dealer who has the professional knowledge and experience to do so. How- ever, the idling speed may be performed by the owner as a p...

  • Page 124

    8-17 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 to the t...

  • Page 125

    8-18 ebu00303 valve clearance adjustment the correct valve clearance changes with use, resulting in improper fuel/air supply or engine noise. To prevent this, the valve clearance must be adjusted regularly. This adjustment however, should be left to a professional yamaha service technician. Ebu00307...

  • Page 126

    8-19 ebu00439 front brake pad inspection apply the brake and inspect the wear indi- cator. If the wear indicator is almost in contact with the disc, ask a yamaha deal- er to replace the pads. 1. Wear indicator ( × 2) a. Wear limit: 1mm (0.04 in) ebu00313 rear brake shoe inspection a wear indicator i...

  • Page 127

    8-20 ebu00315* front brake fluid level inspection insufficient brake fluid may let air enter the brake system, possibly causing the brakes to become ineffective. Before riding, check that the brake fluid is above the lower level and replenish when necessary. Observe these precautions: 1. When checki...

  • Page 128

    8-21 5. Brake fluid may deteriorate painted surfaces or plastic parts. Always clean up spilled fluid immediately. 6. Have a yamaha dealer check the cause if the brake fluid level goes down. Ebu00752 brake fluid replacement 1. Complete fluid replacement should be done only by trained yamaha service p...

  • Page 129

    8-22 warning potential hazard operating with improperly serviced or adjusted brakes. What can happen you could lose braking ability, which could lead to an accident. How to avoid the hazard after servicing: ● make sure the brakes operate smoothly and that the free play is correct. ● make sure the br...

  • Page 130

    8-23 ebu00329 rear brake pedal and lever adjustment 1. Brake pedal free play adjustment a. Fully loosen the adjusting nut on the brake cable. 1. Adjusting nut (brake cable) 2. Adjusting nut (brake rod) b. Turn the adjusting nut on the brake rod until free play is 20 ~ 30 mm (0.8 ~ 1.18 in). A. 20 ~ ...

  • Page 131

    8-24 2. Brake lever free play adjustment a. Loosen the locknut and fully turn in the adjusting bolt at the brake lever. 1. Locknut 2. Adjusting bolt b. Screw in the adjusting nut on brake ca- ble to provide a gap of 0 ~ 1 mm (0 ~ 0.04 in) between the lever and the pin. 1. Adjusting nut (brake cable)...

  • Page 132

    8-25 c. Turn the adjusting bolt until free play at the brake lever pivot is 5 ~ 7 mm (0.20 ~ 0.28 in). 1. Locknut 2. Adjusting bolt a. 5 ~ 7 mm (0.20 ~ 0.28 in) d. Tighten the locknut. Warning potential hazard operating with improperly serviced or adjusted brakes. What can happen you could lose brak...

  • Page 133

    8-26 ebu00346 clutch adjustment 1. Loosen the locknut. 2. Slowly turn the adjusting bolt counter- clockwise until resistance is felt. Then, turn it 1/8 turn clockwise. 1. Locknut 2. Adjusting bolt 3. Tighten the locknut to specification. Note: turn the adjusting bolt counterclockwise to decrease the...

  • Page 134

    8-27 ebu00356 cable inspection and lubrication lubricate the inner cables and the cable ends. If the cables do not operate smooth- ly, ask a yamaha dealer to replace them. Ebu00727 brake and shift pedal/brake lever lubrication lubricate the pivoting parts of each lever and pedal. Warning potential h...

  • Page 135

    8-28 ebu00373 wheel removal 1. Elevate the wheel by placing a suitable stand under the frame. 2. Remove the nuts from the wheel. 3. Remove the wheel assembly. Ebu00702 wheel installation when installing the wheel, reverse the re- moval procedure. Note: the arrow mark on the tire must point toward th...

  • Page 136

    8-29 1. Tapered wheel nuts are used for both front and rear wheels. Install the nut with its tapered side towards the wheel. 1. Tapered nut 2. Tighten the wheel nuts to the specified torque. Ebu00380 battery this machine is equipped with a sealed- type battery. Therefore it is not necessary to check...

  • Page 137

    8-30 ebu00385 battery maintenance 1. When the machine is not used for a month or longer, remove the battery and store it in a cool, dark place. Com- pletely recharge the battery before re- installation. Caution: a special battery charger (constant volt- age/ampere or constant voltage) is re- quired ...

  • Page 138

    8-31 ebu00746* fuse replacement 1. The main fuse case and the fuse box are located under the seat. 2. If a fuse is blown, turn off the main switch and install a new fuse of the specified amperage. Then turn on the switches. If the fuse immediately blows again, consult a yamaha dealer. 1. Main fuse 2...

  • Page 139

    8-32 caution: to prevent accidental short-circuiting, turn off the main switch when checking or replacing a fuse. 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...

  • Page 140

    8-33 ebu00753 replacing the headlight bulb if the headlight bulb burns out, replace the bulb as follows: 1. Remove the headlight assembly by re- moving the screws. 2. Disconnect the coupler. 3. Remove the light unit assembly from the headlight assembly by removing the screw. 4. Remove the bulb holde...

  • Page 141

    8-34 6. Put a new bulb into position and se- cure it in place with the bulb holder. 7. Install the bulb holder cover. Caution: make sure the bulb holder cover is secure- ly fitted over the bulb holder and seated against the reflector. 8. Install the headlight assembly and connect the coupler. 9. Adj...

  • Page 142

    8-35 ebu00409 headlight beam adjustment caution: it is advisable to have a yamaha dealer make this adjustment. 1. Vertical adjustment: to raise the beam, turn the adjusting screw clockwise. To lower the beam, turn the screw counterclockwise. 1. Adjusting screw ( × 2) ebu00412 troubleshooting althoug...

  • Page 143

    8-36 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. Make sure there are no open flames or sparks in th...

  • Page 144

    E 8-37 ebu00440 troubleshooting chart 1. Fuel check if there is fuel in the fuel tank. There is fuel. Turn the fuel cock to “off”. Remove the fuel pipe. Fuel cock clogged. Clean fuel cock. Some fuel. Turn the fuel cock to “res”. Restart engine. No fuel. Supply fuel. 2. Compression use the electric s...

  • Page 145: Cleaning and Storage

    9-1 ebu00419 cleaning and storage a. Cleaning frequent, thorough cleaning of your ma- chine will not only enhance its appearance but will improve its general performance and extend the useful life of many compo- nents. 1. Before cleaning the machine: a. Block off the end of the exhaust pipe to preve...

  • Page 146

    9-2 8 8 8 8 8 8 8 8 9 80 88 88 88 88 6. Clean the seat with a vinyl upholstery cleaner to keep the cover pliable and glossy. 7. Automotive type wax may be applied to all painted and chrome plated sur- faces. Avoid combination cleaner- waxes. Many contain abrasives which may mar the paint or protecti...

  • Page 147

    9-3 ebu00530 b. Storage long term storage (60 days or more) of your machine will require some preventive procedures to guard against deterioration. After thoroughly cleaning the machine, prepare for storage as follows: 1. Fill the fuel tank with fresh fuel and add the specified amount of yamaha fuel...

  • Page 148

    9-4 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..

  • Page 149: Specifications

    E 10-1 ebu00428 specifications model yfm400n dimension: overall length overall width overall height seat height wheel base minimum ground clearance minimum turning radius 2,007 mm (79.0 in) 1,125 mm (44.3 in) 1,172 mm (46.1 in) 855 mm (33.7 in) 1,230 mm (48.4 in) 245 mm (9.65 in) 3,000 mm (118.1 in)...

  • Page 150

    10-2 e engine oil: type quantity: periodic oil change with oil filter replacement total amount see page 5-7 2.9 l (2.6 imp qt, 3.1 us qt) 3.0 l (2.6 imp qt, 3.2 us qt) 3.5 l (3.1 imp qt, 3.7 us qt) final gear oil: type quantity periodic oil change total amount sae 80 api “gl-4” hypoid gear oil 0.23 l...

  • Page 151

    E 10-3 transmission: primary reduction system primary reduction ratio secondary reduction system secondary reduction ratio transmission type operation gear raito: 1st 2nd 3rd 4th 5th reverse gear spur gear 76/24 (3.167) shaft drive 28/24 × 24/18 × 33/09 (5.703) constant mesh 5-speed forward, 1-speed...

  • Page 152

    10-4 e suspension: front rear double wishbone swingarm (monocross) shock absorber: front rear coil spring/oil damper coil spring/oil damper wheel travel: front wheel travel rear wheel travel 150 mm (5.91 in) 150 mm (5.91 in) electrical: ignition system generator system battery type/voltage, capacity...

  • Page 153: Noise Regulation

    E 11-1 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 desi...

  • Page 154: Maintenance Record

    12-1 e 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 ...

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    E 13-1.

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    13-2 13 13 13 13 13 13 13 13 13 130 1313 1313 13 1313.

  • Page 157

    E 14-1.

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    14-2 14 14 14 14 14 14 14 14 14 140 1414 1414 1414 14.

  • Page 159

    E 14-3 ebu00436 warning indicates a potential hazard that could result in serious injury or death..

  • Page 160

    E 14-5 ebu00437.

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    Printed in usa 2000 · ? - ?.? × 1 cr (e) printed on recycled paper warning always : • use proper riding techniques to avoid vehicle overturns on hills and rough terrain and in turns. • avoid paved surfaces-pavement may seriously affect handling and control. Improper atv use can result in severe inju...