1. DL manuals
  2. Yamaha
  3. Offroad Vehicle
  4. BIG BEAR YFM400S
  5. Owner's Manual

Yamaha BIG BEAR YFM400S Owner's Manual

Summary of BIG BEAR YFM400S

  • Page 1

    5gw-f8199-14 lit-11626-17-08 read this manual carefully! It contains important safety information. This atv should not be ridden by anyone under 16 years of age. Warning yfm400s owner’s manual printed in usa 2003.04-1.3 ×1 cr (e) printed on recycled paper yamaha motor co., ltd. Ebu00438 locate and r...

  • Page 2

    Ebu00776.

  • Page 3: Introduction

    Ebu00941 1- introduction congratulations on your purchase of the yamaha yfm400. It represents the result of many years of yamaha experience in the production of fine sporting, touring, and pace-setting racing atvs. With the purchase of this yamaha, you can now appreciate the high degree of craftsman...

  • Page 4: Important Manual Information

    Ebu00801 1- 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 notations: the safety alert symbol means attention! Become alert! Your safety is...

  • Page 5: Important Notice

    Affix dealer label here 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 regula...

  • Page 6: Warning

    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 rec...

  • Page 7

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

  • 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 adjustment.........................

  • 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 u5gw14.Book page 1 thursday, april 10, 2003 3:49 pm.

  • 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 information 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 yo...

  • Page 12

    1-3 4 5 6 overloading this atv or carrying cargo improperly can change handling. Stability and braking performance and can lead to an accident. Never exceed the maximum rear cargo limit of : 80kg (176 lbs) never sit on the carrier. Refer to instructions in the owner's manual. 5nd-f4897-00 warning u5...

  • Page 13: Maximum.Loading Limit

    1-4 7 8 pulling load: 4020 n ( 4 1 0 k g f ) 904 l b f tongue weight: 147 n ( 1 5 k g f ) 33 l b f 5fu-f151k-00 maximum.Loading limit maximum loading limit u5gw14.Book page 4 thursday, april 10, 2003 3:49 pm.

  • Page 14: Safety Information

    2-1 safety information ebu00924 an atv is not a toy and can be hazardous to operate. An atv handles differently 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 obstacles, if you f...

  • Page 15

    2-2 1 2 3 4 5 6 7 8 9 10 11 12 13 14 ● always avoid operating an atv on any paved surfaces, including sidewalks, driveways, park- ing 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

    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 excessive speed. ● never operate the atv on hills too steep for the atv or for your abilities. Practice on smaller hills before att...

  • Page 17

    2-4 ● always use proper procedures if you stall or roll backwards when climbing a hill. To avoid stall- ing, use proper gear and maintain a steady speed when climbing a hill. If you stall or roll back- wards, follow the special procedure for braking described in this manual. Dismount on the uphill s...

  • Page 18

    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 distributed a...

  • Page 19: Warning

    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: Warning

    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 atv in an area with adequate ventilation. U5gw14.Book page 7 thursd...

  • Page 21

    3-1 1 2 3 4 5 6 7 8 9 10 11 12 13 14 ebu00032 description and machine identification 1. Spark arrester 2. Rear carrier 3. Seat 4. Auxiliary dc jack 5. Front carrier 6. Brake pedal 7. Headlights 8. Fuel cock 9. Recoil starter 10. Tail/brake light 11. Rear wheel 12. Shift pedal 13. Front wheel 14. Rea...

  • Page 22

    3-2 ebu00600 identification number records record the key identification number, vehicle identification number and model label infor- mation in the spaces provided for assistance when ordering spare parts from a yamaha dealer or for reference in case the vehicle is stolen. 1. Key identification numb...

  • 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. Ebu00787 model label the model label is affixed to the location in the illustration. Reco...

  • Page 24: Control Functions

    4-1 ebu00039 control functions warning indicates a potential hazard that could result in serious injury or death. Ebu00942 main switch functions of the respective switch positions are as follows: on: the engine can be started only at this position and the headlights and taillight come on when the li...

  • Page 25: Caution:

    4-2 1 2 3 4 5 6 7 8 9 10 11 12 13 14 ebu00802 indicator and warning 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 trans- mission is in reve...

  • Page 26

    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. Eng...

  • Page 27

    4-4 ebu00051 speedometer the speedometer shows riding speed. This speedometer is equipped with an odometer and trip odometer. The trip odometer can be reset to “0” with the reset knob. Use the trip odometer to estimate how far you can ride on a tank of fuel before going to reserve. This in- formatio...

  • Page 28: Caution:

    4-5 ebu00053 handlebar switches 1. Lights switch “ / /off” 2. Engine stop switch “ ”/“ ” 3. Start switch “ ” ebu01205 engine stop switch “ / ” make sure that the engine stop switch is set to “ ” before starting the engine. The engine stop switch controls ignition and can be used at all times to stop...

  • Page 29: Warning

    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: Warning

    4-7 ebu01159 speed limiter the speed limiter keeps the throttle from fully opening, even when the throttle lever is pushed to the maximum. Turning in the ad- justing screw limits the maximum engine pow- er available and decreases the maximum speed of the atv. 1. Locknut 2. Adjusting screw a. 12 mm (...

  • Page 31

    4-8 ebu00070 front brake lever the front brake lever is located on the right handlebar. Pull it toward the handlebar to ap- ply the front brake. 1. Front brake lever ebu00732 brake pedal and rear brake lever the brake pedal is located on the right side of the atv and the rear brake lever is located ...

  • Page 32: Warning

    4-9 ebu00074 parking brake use the parking brake when you have to start the engine or park the machine, especially on a slope. Apply the rear brake lever and push down the lock plate to apply the parking brake. Squeeze the rear brake lever to re- lease the parking brake. 1. Lock plate warning potent...

  • Page 33

    4-10 ebu00084 shift pedal this machine is equipped with a constant- mesh 5-speed forward and 1-speed reverse transmission. The shift pedal is located on the left side of the engine. Reverse is at the bot- tom position. Neutral is one position above re- verse. 1. Shift pedal ebu10280 reverse knob “re...

  • Page 34: Warning

    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 coun- terclockwise. 1. Fuel tank cap u5gw14.Book page 12 thursday, april 10, 2003 3:49 pm.

  • 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 supplies 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 proper op- era...

  • 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: Caution:

    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: 2.0 kg (4.4 lb...

  • Page 40: Warning

    4-17 ebu01104 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- justing ring in direction a. To decrease the spring preload, turn the ad- justing ring...

  • Page 41

    4-18 ebu01103 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- justing ring in direction a. To decrease the spring preload, turn the ad- justing ring ...

  • Page 42

    4-19 ebu01002 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, radios, etc. The auxiliary dc jack should only be used when the engine is running. 1. Set the light switch to “off”. 2. Start the engine. (...

  • Page 43: Caution:

    4-20 caution: _ ● do not use accessories requiring more than the above maximum capac- ity. This may overload the circuit and cause the fuse to blow. ● if accessories are used without the engine running or with the headlights turned on, the battery will lose its charge and engine starting may be- com...

  • Page 44: Pre-Operation Checks

    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, 8-21–8-28 rear brake • check operation, condition and free play. • adjust if...

  • Page 45: Warning

    5-2 1 2 3 4 5 6 7 8 9 10 11 12 13 14 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 mak...

  • Page 46

    5-3 ebu12521 front and rear brakes brake levers and brake pedal ● check for correct free play in the front brake lever. If the free play is incorrect, have a yamaha dealer adjust it. ● check for correct free play in the rear brake lever and brake pedal. If the free play is in- correct, adjust it. (s...

  • Page 47: Warning

    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: Caution:

    5-5 ebu01085 fuel make sure there is sufficient gasoline in the tank. Caution: _ use only unleaded gasoline. The use of leaded gasoline will cause severe damage to internal engine parts, such as the valves and piston rings, as well as to the exhaust system. _ your yamaha engine has been designed to ...

  • Page 49: Warning

    5-6 gasohol there are two types of gasohol; gasohol con- taining ethanol and that containing methanol. Gasohol containing ethanol can be used if ethanol content does not exceed 10%. Gaso- hol containing methanol is not recommended by yamaha because it may cause fuel system damage or vehicle performa...

  • Page 50: Caution:

    5-7 ebu10842 engine oil make sure the engine oil is at the specified level. Add oil as necessary. (see page 8-5.) caution: _ ● in order to prevent clutch slippage (since the engine oil also lubricates the clutch), do not mix any chemical additives. Do not use oils with a diesel specification of “cd”...

  • Page 51

    5-8 ebu01083 throttle lever check to see that the throttle lever operates correctly. It must open smoothly and spring back to the idle position when released. Have a yamaha dealer repair as necessary for proper operation. Ebu01162 fittings and fasteners always check the tightness of chassis fittings...

  • Page 52: Warning

    5-9 ebu00157 tires warning potential hazard operating this atv with improper tires, or with improper or uneven tire pressure. What can happen use of improper tires on this atv, or op- eration of this atv with improper or un- even tire pressure, may cause loss of control, increasing your risk of acci...

  • Page 53

    5-10 4. Use no more than the following pres- sures when seating the tire beads. Front 250 kpa (2.5 kgf/cm 2 , 36 psi) rear 250 kpa (2.5 kgf/cm 2 , 36 psi) higher pressures may cause the tire to burst. Inflate the tires very slowly and carefully. Fast inflation could cause the tire to burst. U5gw14.B...

  • 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 second reading. Dust or dirt in the gauge could cause the first reading to be incorrect. Set press...

  • 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. Tire wear limit u5gw14.Book page 12 thursday, april 10, 2003 3:49 pm.

  • Page 56: Operation

    6-1 ebu00161 operation warning indicates a potential hazard that could result in serious injury or death. Ebu00749 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 en- gine stop switch to “ ”. 4. Shift the transmission into neutr...

  • Page 57

    6-2 1 2 3 4 5 6 7 8 9 10 11 12 13 14 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. However, it is recommended to sh...

  • Page 58: Caution:

    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 battery en- ergy. Do not crank the engine more than 10 seconds on each attempt. ● if the batte...

  • Page 59: Caution:

    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: Caution:

    6-5 ebu12951 shifting this model has a 5-speed forward and 1-speed reverse transmission with centrifugal automatic clutch. The transmission allows you to control the amount of power you have avail- able at a given speed or for starting, acceler- ating, climbing hills, etc. To shift into neutral, ret...

  • Page 61: Caution:

    6-6 ebu00205 to start out and accelerate: 1. Release the throttle lever. Caution: always close the throttle while shifting gears. Otherwise, damage to the engine and drive train may result. 2. Shift into first gear and release the shift pedal. 3. Open the throttle gradually. 4. Once the machine has ...

  • Page 62: Warning

    6-7 ebu00207 to decelerate: 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 sufficiently slowed before engaging a lower gear. Improp- er use of the brakes or shifting can cause the tire...

  • Page 63

    6-8 each full throttle acceleration sequence should be followed with a substantial rest pe- riod for the engine by cruising at lower r/min so the engine can rid itself of the temporary build up of heat. If any abnormality is noticed during this peri- od, consult a yamaha dealer. 0–10 hours: avoid co...

  • Page 64: Warning

    6-9 ebu00211 parking when parking, stop the engine and shift into neutral. Turn the fuel cock to “off” and apply the parking brake. 1. Locked position ebu01296 parking on a slope warning potential hazard parking on a hill or other incline. What can happen the atv could roll out of control, in- creas...

  • Page 65

    6-10 1. Bring the atv to a stop by applying 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 brake pedal. U5gw14.Book page 10 thursday, april 10, 2003 3:49 pm.

  • Page 66

    6-11 ebu00221 accessories and loading ebu00222 accessories accessories can affect the handling and con- trol 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 vari...

  • Page 67

    6-12 ebu00588 loading cargo or a trailer can change the stability and handling of an atv. You must use common sense and good judg- ment 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 exce...

  • Page 68: Warning

    6-13 ● ride more slowly than you would without a load. The more weight you carry, the slow- er you should go. Although conditions vary, it is good practice not to exceed 2nd gear whenever you are carrying heavier loads or when towing a trailer. ● allow more braking distance. A heavier ve- hicle take...

  • Page 69: Riding

    7-1 7 riding your atv u5gw14.Book page 1 thursday, april 10, 2003 3:49 pm.

  • Page 70

    7-2 u5gw14.Book page 2 thursday, april 10, 2003 3:49 pm.

  • Page 71: Warning

    7-3 warning _ indicates a potential hazard that could result 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 in- structions for recreational riding. The skills and...

  • Page 72: Warning

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

  • Page 73: Warning

    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 74: Warning

    7-6 this atv 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 accident, resulting in harm to you and/ or your passenger. How to...

  • Page 75: Warning

    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 in- creases your chances of a severe head injury or death in the event of an accident. Op...

  • Page 76: Warning

    7-8 do not operate after consuming alcohol or drugs. Operator’s performance capability is reduced 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 more ...

  • Page 77: Warning

    7-9 pre-operation checks always perform the pre-operation checks list- ed on page 5-1 before riding for safety and proper care of the atv. 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 acc...

  • Page 78: Warning

    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 less experienced with this model, this model is equipped with a speed limiter in the throttle lever housing. The spe...

  • Page 79: Warning

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

  • Page 80: Warning

    7-12 during operation always keep your feet on the footboards dur- ing operation. Otherwise your feet may con- tact 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 abil...

  • Page 81: Warning

    7-13 avoid wheelies and jumping. You may lose control of the atv 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. ...

  • Page 82: Warning

    7-14 modifications warning potential hazard operating this atv with improper modi- fications. 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 83: Warning

    7-15 exhaust system the exhaust system on the atv is very hot during and following operation. To prevent burns, avoid touching the exhaust system. Park the atv in a place where pedestrians or children are not likely to touch it. Warning potential hazard hot exhaust system. What can happen dry grass ...

  • Page 84: Warning

    7-16 be careful where you ride this atv 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 cont...

  • Page 85: Warning

    7-17 do not ride on any public road, street, or high- way. Riding on public roads can result in collisions 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 86: Warning

    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 oth- er hidden hazards which may cause the atv to upset. Warning potential hazard failure to use extra care when operating this atv on unfamiliar terrain. What can h...

  • Page 87: Warning

    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 88: Warning

    7-20 when riding in an area where you might not easily be seen, such as desert terrain, mount a caution flag on the atv. Do not use the flag pole bracket as a trailer hitch. Do not ride in areas posted “no trespassing”. Do not ride on private property without getting permission. Warning potential ha...

  • Page 89

    7-21 select a large, flat area off-road to become fa- miliar 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. Al- ways avo...

  • Page 90: Caution:

    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 sufficiently slowed b...

  • Page 91: Warning

    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 in- side of the turn is allowed to slip or lose some traction, the atv will resist turning. A special ...

  • Page 92

    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 sur- face is slippery or ...

  • Page 93: Warning

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

  • Page 94: Warning

    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 95: Warning

    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 96: Warning

    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, dis- mount the atv on the uphill side. Physically turn the atv aroun...

  • Page 97

    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. U5gw14.Book page 29 thursday, april 10, 2003 3:49 pm.

  • Page 98: Warning

    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 compression to do most of the braking for you. Improper braking may ca...

  • Page 99

    7-31 u5gw14.Book page 31 thursday, april 10, 2003 3:49 pm.

  • Page 100: Warning

    7-32 crossing a slope traversing a sloping surface on your atv re- quires 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 t...

  • Page 101

    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. U5gw14.Book page 33 thursday, april 10, 2003 3:49 pm.

  • Page 102: Warning

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

  • Page 103: Caution:

    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...

  • Page 104: Warning

    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 footboards at all times. Avoid jumping the atv as loss of control an...

  • Page 105

    7-37 u5gw14.Book page 37 thursday, april 10, 2003 3:49 pm.

  • Page 106

    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, sliding could lead to an accident. To reduce the tendency for the front wheels to slide in loose or slippery conditions, position- ing your weight over the ...

  • Page 107: Warning

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

  • Page 108

    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 109: Warning

    7-41 ● if your atv is traversing a sloping surface: be sure to ride with your weight positioned towards the uphill side of the atv to main- tain 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 dis- cover that the atv is ...

  • Page 110: Periodic Maintenance and

    8-1 ebu00515 periodic maintenance and adjustment periodic inspection, adjustment and lubrica- tion 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 machine inspection, ad- justment and lubrication a...

  • Page 111: Warning

    8-2 1 2 3 4 5 6 7 8 9 10 11 12 13 14 1. Owner’s tool kit 2. Low-pressure tire gauge the service information included in this man- ual is intended to provide you, the owner, with the necessary information for completing your own preventive maintenance and minor re- pairs. The tools provided in the ow...

  • Page 112

    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 element • clean. • replace if necessary....

  • Page 113: Warning

    8-4 * items marked with an asterisk should be performed by a yamaha dealer as they require special tools, data and technical skills. Wheels* • check balance/damage/run out. • replace if necessary. Wheel bearings* • check bearing assemblies for looseness/damage. • replace if damaged. Steering system*...

  • Page 114: Caution:

    8-5 ebu11812 engine oil and oil filter element the engine oil level should be checked before each ride. In addition, the oil must be changed and the oil filter element cleaned at the inter- vals specified in the periodic maintenance and lubrication chart. To check the engine oil level 1. Place the a...

  • Page 115: Caution:

    8-6 6. Insert the dipstick into the oil filler hole, and then tighten the engine oil filler cap. 1. Dipstick 2. Maximum level mark 3. Minimum level mark to change the engine oil (with or without oil filter element cleaning) 1. Place the atv on a level surface. 2. Warm up the engine for several minut...

  • Page 116

    8-7 1. Engine oil drain bolt 2. O-ring 3. Compression spring 4. Engine oil strainer 5. Remove the oil filter cover by removing the bolts, and then remove the oil filter el- ement. 1. Engine oil filter cover 2. Engine oil filter cover bolt ( × 3) 6. Clean the oil strainer and oil filter element with ...

  • Page 117: Caution:

    8-8 9. Install the oil filter cover by installing the bolts, and then tighten them to the speci- fied torque. 10. Install the oil strainer, compression spring, o-ring and engine oil drain bolt. Tighten the engine oil drain bolt to the specified torque. Caution: _ before installing the engine oil dra...

  • Page 118: Caution:

    8-9 caution: _ ● in order to prevent clutch slippage (since the engine oil also lubricates the clutch), do not mix any chemical additives. Do not use oils with a diesel specification of “cd” or oils of a high- er quality than specified. In addition, do not use oils labeled “energy conserving ii” or ...

  • Page 119: Caution:

    8-10 ebu01145 final gear oil final gear oil measurement 1. Place the machine on a level surface. 2. Remove the oil filler bolt, and then check the oil level in the final gear case. Note: _ the oil level should be at the brim of the filler hole. _ 3. If the oil is below the brim of the filler hole, a...

  • Page 120

    8-11 final gear oil replacement 1. Remove the final gear case cover by re- moving the bolts. 1. Final gear case cover 2. Bolt ( × 2) 2. Place the machine on a level surface. 3. Place a container under the final gear case to collect the used oil. 4. Remove the oil filler bolt and the drain bolt to dr...

  • Page 121: Caution:

    8-12 6. Add the recommended final gear oil to the brim of the filler hole. Caution: _ be sure no foreign material enters the final gear case. _ 7. Install the oil filler bolt. 8. Check for oil leakage. If oil leakage is found, check for the cause. 9. Install the final gear case cover bolts, and then...

  • Page 122

    8-13 before installing the spark plug, measure the electrode gap with a wire thickness gauge and adjust it to specification. A. Spark plug gap when installing the spark plug, always clean the gasket surface and its mating surface. Wipe off any grime from the threads and tight- en it to the specified...

  • Page 123

    8-14 1. Air filter case cover 2. Holder ( × 3) 3. Pull the air filter element out. 1. Air filter element 4. Remove the foam cover from the air filter element. 1. Air filter element 2. Foam cover u5gw14.Book page 14 thursday, april 10, 2003 3:49 pm.

  • Page 124: Caution:

    8-15 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 air filter element is damaged, replace it. 6. Wash the foam cover gently but thor- oughly in water or solvent. 7. Squeeze the excess water or solvent out of the foam ...

  • Page 125: Caution:

    8-16 10. Install the air filter element. 11. Install the air filter case cover by fasten- ing the holders. 12. Install the seat. Note: _ the air filter element should be cleaned every 20–40 hours. It should be cleaned more often if the atv is operated in extremely dusty ar- eas. Each time air filter...

  • Page 126

    8-17 ebu00754 spark arrester cleaning select a well-ventilated area free of combusti- ble materials and make sure the exhaust pipe and muffler are cool. 1. Remove the purging bolt. 1. Purging bolt 2. Start the engine and rev it up approxi- mately twenty times while momentarily creating exhaust syste...

  • Page 127: Caution:

    8-18 ebu00296 carburetor adjustment the carburetor is a vital part of the engine and requires very sophisticated adjustment. Most adjusting should be left to a yamaha dealer who has the professional knowledge and ex- perience to do so. However, the idling speed may be performed by the owner as a par...

  • Page 128

    8-19 ebu01302 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 engine to 4,000 to 5,000 r/min. The engine is warm when it quickly responds to the t...

  • Page 129

    8-20 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 clear- ance must be adjusted regularly. This adjust- ment however, should be left to a professional yamaha service technician. Ebu0...

  • Page 130

    8-21 ebu13031 front brake pad check inspect the brake pads for damage and wear. If the brake pad thickness is less than 1 mm (0.04 in), have a yamaha dealer replace the pads as a set. A. Brake pad thickness ebu00313 rear brake shoe inspection a wear indicator is provided on the rear brake. This indi...

  • Page 131

    8-22 ebu01304 brake fluid level check 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 minimum level mark and replenish if necessary. A low brake fluid level may indi- cate worn brak...

  • Page 132

    8-23 ● brake fluid may deteriorate painted surfac- es or plastic parts. Always clean up spilled fluid immediately. ● have a yamaha dealer check the cause if the brake fluid level goes down. Ebu01186 brake fluid replacement complete fluid replacement should be done only by trained yamaha service pers...

  • Page 133: Warning

    8-24 ebu11870 front brake lever free play the front brake lever should have a free play of zero mm (zero in) at the lever end. If not, have a yamaha dealer check the brake sys- tem. A. Front brake lever free play warning potential hazard operating with improperly serviced or adjusted brakes. What ca...

  • Page 134

    8-25 ebu13052 brake pedal and rear brake lever adjustment brake pedal free play adjustment 1. Fully loosen the adjusting nut on the brake cable. 1. Adjusting nut (brake cable) 2. Adjusting nut (brake rod) 2. Turn the adjusting nut on the brake rod until the free play is 20–30 mm (0.79– 1.2 in). A. B...

  • Page 135

    8-26 brake lever free play adjustment 1. Loosen the locknut and fully turn in the adjusting bolt at the brake lever. 1. Locknut 2. Adjusting bolt 2. Turn in the adjusting nut on brake cable to provide a gap of 0–1 mm (0–0.04 in) between the camshaft lever and the pin. 1. Adjusting nut (brake cable) ...

  • Page 136: Warning

    8-27 3. Turn the adjusting bolt until the free play at the brake lever pivot is 5–8 mm (0.20– 0.31 in). 1. Locknut 2. Adjusting bolt a. Rear brake lever free play 4. Tighten the locknut. Warning potential hazard operating with improperly serviced or adjusted brakes. What can happen you could lose br...

  • Page 137

    8-28 ebu00834 adjusting the rear brake light switch the rear brake light switch, which is activated by the brake pedal and brake levers, is prop- erly adjusted when the brake light comes on just before braking takes effect. If necessary, adjust the brake light switch as follows. Turn the adjusting n...

  • Page 138: Warning

    8-29 3. Tighten the locknut to specification. Note: turn the adjusting bolt counterclockwise to decrease the clutch free play and turn it clock- wise to increase the free play. Ebu00356 cable inspection and lubrication tightening torque: 20 nm (2.0 m·kgf, 15 ft·lbf) warning potential hazard damaged ...

  • Page 139

    8-30 lubricate the inner cables and the cable ends. If the cables do not operate smoothly, ask a yamaha dealer to replace them. Ebu00727 brake and shift pedal/brake lever lubrication lubricate the pivoting parts of each lever and pedal. Ebu01112 wheel removal 1. Loosen the wheel nuts. 2. Elevate the...

  • Page 140

    8-31 ebu01121 wheel installation 1. Install the wheel and the nuts. Note: _ ● tapered nuts are used for both the front and rear wheels. Install the nut with its ta- pered side towards the wheel. ● the arrow mark on the tire must point toward the rotating direction of the wheel. _ 1. Arrow mark 2. Lo...

  • Page 141: Caution:

    8-32 ebu00380 battery this machine is equipped with a sealed-type battery. Therefore it is not necessary to check the electrolyte or add distilled water in the bat- tery. If the battery seems to have discharged, consult a yamaha dealer. Caution: do not try to remove the sealing caps of the battery c...

  • Page 142: Caution:

    8-33 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. Completely recharge the battery before reinstallation. Caution: a special battery charger (constant volt- age/ampere or constant voltage) is re- quired for ...

  • Page 143: Caution:

    8-34 1. Main fuse 2. Spare main fuse 1. Headlight fuse 2. Ignition fuse 3. Auxiliary dc jack fuse 4. Carburetor warmer fuse 5. Spare fuse ( × 2) caution: _ to prevent accidental short-circuiting, turn off the main switch when checking or replacing a fuse. _ warning potential hazard using an improper...

  • Page 144

    8-35 ebu13061 replacing a headlight bulb if a headlight bulb burns out, replace the bulb as follows. 1. Remove the headlight assembly by re- moving the screws. 2. Disconnect the headlight coupler. 1. Screw ( × 2) 2. Headlight coupler 3. Remove the headlight unit from the headlight assembly by removi...

  • Page 145: Warning

    8-36 4. Remove the headlight bulb holder cover. 5. Push the headlight bulb holder inward, turn it counterclockwise, and then re- move the defective bulb. 1. Headlight bulb holder cover 2. Headlight bulb holder 6. Put a new headlight bulb into position, and then secure it in place with the bulb holde...

  • Page 146: Caution:

    8-37 1. Do not touch the glass part of the bulb. Caution: _ do not touch the glass part of the head- light bulb to keep it free from oil, otherwise the transparency of the glass, the luminos- ity of the bulb, and the bulb life will be ad- versely affected. Thoroughly clean off any dirt and fingerpri...

  • Page 147: Caution:

    8-38 ebu01089 headlight beam adjustment caution: _ it is advisable to have a yamaha dealer make this adjustment. _ to raise the beam, turn the adjusting screw in direction a. To lower the beam, turn the adjusting screw in direction b. 1. Adjusting screw ebu09451 tail/brake light bulb replacement 1. ...

  • Page 148

    8-39 1. Tail/brake light bulb holder 4. Remove the defective bulb from the bulb holder by pushing it inward and turning it counterclockwise. 1. Tail/brake light bulb holder 2. Bulb 5. Install a new bulb in the bulb holder by pushing it inward and turning it clockwise. 6. Install the bulb holder (tog...

  • Page 149: Warning

    8-40 ebu00412 troubleshooting although yamaha machines receive a rigid in- spection before shipment from the factory, trouble may occur during operation. Any prob- lem in the fuel, compression, or ignition sys- tems can cause poor starting and loss of power. The troubleshooting chart describes a qui...

  • Page 150

    8-41 ebu00440 troubleshooting chart 1. Fuel check if there is fuel in the fuel tank. There is fuel. Turn the fuel cock lever to “off”. No fuel. Fuel cock is clogged. Clean the fuel cock. Some fuel. Turn the fuel cock lever to “res”. Restart the engine. No fuel. Supply fuel. 2. Compression use the el...

  • Page 151: Cleaning and Storage

    9-1 1 2 3 4 5 6 7 8 9 10 11 12 13 14 ebu00419 cleaning and storage a. Cleaning frequent, thorough cleaning of your machine will not only enhance its appearance but will improve its general performance and extend the useful life of many components. 1. Before cleaning the machine: a. Block off the end...

  • Page 152: Warning

    9-2 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 surfaces. Avoid combination cleaner-waxes. Many contain abrasives which may mar the paint or protective finish. When finished, start the ...

  • Page 153

    9-3 ebu00530 b. Storage long term storage (60 days or more) of your machine will require some preventive proce- dures 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 fu...

  • Page 154

    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 ex- cessively 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. U5gw14.Book page 4 thursday...

  • Page 155: Specifications

    10-1 1 2 3 4 5 6 7 8 9 10 11 12 13 14 ebu00428 specifications model yfm400 dimension: overall length overall width overall height seat height wheel base 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 ( ...

  • Page 156

    10-2 engine oil: type recommended engine oil classification api service se, sf, sg or higher quantity: without oil filter element replacement with oil filter element replacement 2.9 l (2.6 imp qt, 3.1 us qt) 3.0 l (2.6 imp qt, 3.2 us qt) model yfm400 0˚ 10˚ 30˚ 50˚ 70˚ 90˚ 110˚ 130˚f yamalube 4 (10w...

  • Page 157

    10-3 final gear oil: type quantity periodic oil change sae 80 api “gl-4” hypoid gear oil 0.23 l (0.20 lmp qt, 0.24 us qt) air filter: dry type element fuel: type tank capacity reserve amount unleaded gasoline only 15 l (3.3 imp gal, 4.0 us gal) 4.0 l (0.9 imp gal, 1.1 us gal) carburetor: type/manufa...

  • Page 158

    10-4 transmission: primary reduction system primary reduction ratio secondary reduction system secondary reduction ratio transmission type operation gear raito: 1st 2nd 3rd 4th 5th reverse spur gear 76/24 (3.166) shaft drive 28/24 × 24/18 × 33/09 (5.703) constant mesh, 5-speed forward, 1-speed rever...

  • Page 159

    10-5 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 dc...

  • Page 160

    10-6 fuses: main fuse headlight fuse ignition fuse auxiliary dc jack fuse carburetor warmer fuse 30 a 15 a 10 a 10 a 10 a model yfm400 u5gw14.Book page 6 thursday, april 10, 2003 3:49 pm.

  • Page 161: Noise Regulation

    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 rendering inop- erative by any person other than for purposes of maintenance, repair, or replacement of any de- vice or element of design...

  • Page 162: Maintenance Record

    12-1 1 2 3 4 5 6 7 8 9 10 11 12 13 14 ebu00431 maintenance record copies of work orders and/or receipts for parts you purchase and install will be required to docu- ment maintenance done in accordance with the warranty. The chart below is printed only as a re- minder to you that the maintenance work...

  • Page 163

    13-1 ebu00432 yamaha motor corporation, u.S.A. Atv limited warranty u5gw14.Book page 1 thursday, april 10, 2003 3:49 pm.

  • Page 164

    13-2 1 2 3 4 5 6 7 8 9 10 11 12 13 14 u5gw14.Book page 2 thursday, april 10, 2003 3:49 pm.

  • Page 165

    14-1 ebu00435 yamaha extended service (y.E.S.) u5gw14.Book page 1 thursday, april 10, 2003 3:49 pm.

  • Page 166

    14-2 1 2 3 4 5 6 7 8 9 10 11 12 13 14 u5gw14.Book page 2 thursday, april 10, 2003 3:49 pm.

  • Page 167: Warning

    Ebu00436 warning indicates a potential hazard that could result in serious injury or death. U5gw14.Book page 3 thursday, april 10, 2003 3:49 pm.

  • Page 168

    Ebu00437 u5gw14.Book page 5 thursday, april 10, 2003 3:49 pm.

  • Page 169: 5Gw-F8199-14

    5gw-f8199-14 lit-11626-17-08 read this manual carefully! It contains important safety information. This atv should not be ridden by anyone under 16 years of age. Warning yfm400s owner’s manual printed in usa 2003.04-1.3 ×1 cr (e) printed on recycled paper yamaha motor co., ltd. Ebu00438 locate and r...

  • Page 170

    Card.Fm page 1 wednesday, june 13, 2001 9:35 am.

  • Page 171

    Card.Fm page 2 wednesday, june 13, 2001 9:35 am.