Select Your Model Yamaha To Download A Manual

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YFM50       YFM80       YFM90       YFM125       YFM250       YFM350        YFM400

YFM450      YFM550     YFM600     YFM660       YFM700       YSF200  


The Yamaha YFM & YSF service manual downloads for the above listed models describes the service procedures for the complete vehicle. Follow the Maintenance Schedule recommendations to ensure that the all-terrain vehicle (ATV) is in peak operating condition and the emission levels are within the standards set by the your states/county Resources Board. Performing the scheduled maintenance is very important. It compensates for the initial wear that occurs during the life of the ATV or utility vehicle.
 
All chapters in the Yamaha YFM & YSF service manuals apply to the whole vehicle and illustrates procedures for removal/installation of components that are in detailed step-by-step fashion.
 
Most all service manual chapters start with an assembly or system illustration, diagrams, exploded parts view, quality pictures, service information and troubleshooting for the section. The subsequent pages give detailed procedures. If you don’t know the source of the trouble, go to the troubleshooting page for a list of causes and effects to determine the problem.


Related Yamaha YFM Searches:

AUXILIARY BRAKE REMOVAL / INSTALL

Brake Pedal Removal / Install

1. To remove the brake pedal:

  • Remove the footwell
  • Remove the cotter key that secures the brake pedal
  • Remove the washers, bushings, and tension spring

2. Reverse the steps for installation, use a new cotter key during installation.

Rear Brake Master Cylinder Removal / Install

1. If necessary, remove the rear brake line from the master cylinder. Use a suitable container to catch the brake fluid. Dispose of brake fluid properly.
2. Remove the two bolts that secure the rearmaster cylinder to the brake mount plate. Replace parts as needed.
3. To install the rear brake master cylinder, mount themaster cylinder to themount plate and torque bolts to 8 ft.lbs. (11 Nm).
4. Reinstall the brake line and torque the banjo bolt to 15 ft.lbs. (21 Nm).

REAR CALIPER ASSEMBLY

1. Install newO-rings in the slide bolt bushing holes. Be sure O-ring and seal grooves are thoroughly cleaned of all residue, or piston may bind in bore. Apply brake fluid to piston seals and install
carefully with a twisting motion to ease assembly until fully seated.
2. Carefully assemble caliper body, making sure O-rings are properly positioned in groove. Tighten the caliper anvil bolts and then torque the anvil bolts evenly to 16--18 ft. lbs. (22--25 Nm).
3. Install brake pads in caliper body with friction material facing each other. Install the slide pins and the slide pin retaining ring. Torque the slide pins to 30--35 ft.lbs. (41--48 Nm). NOTE: Torquing the slide pins while the caliper is mounted on the ATV simplifies the torque procedure.

REAR BRAKE PAD INSTALLATION

1. Insert new brake pads into the caliper. NOTE: If pads are greasy, dirty, oily, or fluid soaked DO NOT use the pads, use only new clean pads.
2. Install slide pin (B) finger tight.
3. Install the caliper onto the caliper mount. Install two bolts and tighten, then torque to 18 ft.lbs. (25 Nm).
4. Torque the slide pin to 30--35 ft.lbs. (41--48 Nm).
5. Install the snap ring.
6. Slowly pump the brake lever until pressure has been built up. Maintain at least 1/2″ (12.7 mm) of brake fluid in the reservoir to prevent air from entering the master cylinder.
7. It is recommended that a burnishing procedure be performed after installation of new brake pads to extend service life and reduce noise. Start machine and slowly increase speed to 30 mph.
Gradually apply brakes to stop machine. Repeat procedure 10 times.

TRANSMISSION DISASSEMBLY

1. Remove gear position switch.
2. Place bellcrank in neutral position.
3. Remove sprocket retaining clip and sprocket.
4. Remove the transmission cover bolts.
5. With a soft face hammer tap on the cover bosses and carefully remove the cover.
6. Remove snap ring from front drive input shaft.
7. Remove output shaft and gear assembly along with sprocket and chain, by tapping on shaft with a soft faced hammer, from the back side of the gear case.
8. Remove roller chain. Note position of sprockets and gear. Stretch chain tight on a flat surface and measure the length of 8 pitches in a minimum of three places on chain. Replace chain if measurement is longer than 5.05I (128.27 mm).
9. Use a 1/2″ wrench to rotate bell crank and remove shift fork, upper shaft assembly, reverse chain and shaft.
10. Inspect shift fork surface for wear or damage. Replace if necessay.
11. Remove reverse shaft bearing.

CONCENTRIC SWINGARM REAR HOUSING REMOVAL

1. Remove rear axle.
2. Remove the caliper mounting bracket (A) from the side of the axle housing.
3. Remove the rear housing from the swingarm.
4. Inspect housing for cracks or wear. Replace if damaged.

FRONT DRIVE AXLE INSTALLATION

1. Install spring washer and drive shaft. Align hole in U-joint yoke with hole in eccentric shaft, and install new roll pin.
2. Install new seal in strut casting.
3. Install drive shaft in strut.
4. Install lower ball joint, torque nut to 25 ft. lbs. (34.5 Nm) and install new cotter pin.
5. Follow procedure to install hilliard clutch components and hub as outlined in this chapter.
6. Tighten hub nut following procedures as outlined in this chapter.

DRIVESHAFT AND CV JOINT HANDLING TIPS

Care should be exercised during driveshaft removal or when servicing CV joints. Driveshaft components are precision parts.
Cleanliness and following these instructions is very important to ensure proper shaft function and a normal service life.
The complete driveshaft and joint should be handled by getting hold of the interconnecting shaft to avoid

DRIVE CLUTCH COVER - BUSHING INSTALLATION

1. Apply Loctitet 680 (PN 2870584) to the back side of new bushing. Working from inside of cover, insert bushing and bushing installation tool into center of clutch cover.
2. With the Main Puller Adapter (#8) (PN 5020632) on the puller, insert cover onto puller rod, placing outside of cover toward vise.
3. Install nut on rod and hand tighten. Turn puller barrel to apply more tension if needed.
4. Turn clutch cover and barrel together counterclockwise on puller rod until bushing is seated.
5. Remove nut from puller rod and take installation tool and clutch cover off rod.

DRIVEN CLUTCH DISASSEMBLY/INSPECTION

1. Apply and hold downward pressure on the helix, or place driven clutch in the Clutch Compression Tool (PN 8700220).
2. Remove snap ring retainer.
3. Note the location of the spring and remove helix.
4. Note the location of the spring in the moveable sheave, and remove the spring.
5. Check alignment of tabs on spring. Replace the spring if tabs aremisaligned or the spring coils are distorted.
6. Inspect ramp buttons in themoveable sheaveand replace if worn. NOTE: The ramp buttons are secured by Torxt screws (T20).
7. Remove moveable sheave and note the number of spacer washers. One spacer must remain between the sheaves when adjusting belt deflection.
8. Inspect the Teflont coating on the moveable sheave bushing.
9. Inspect driven clutch faces for wear or damage.
10. Clean and inspect splines on helix and transmission input shaft.
11. Lube splines with a light film of grease. Do not lubricate the bushings!

PILOT SCREW

The pilot systemsupplies fuel during engine operation with the throttle valve closed or slightly opened. The fuel/air mixture is metered by pilot screw and discharged into themain bore through the pilot outlet.The pilot screw is calibrated at the factory to meet EPA / CARB regulations for air quality standards and is sealed with a brass plug to prevent tampering. Removal of the tamper proof plug is not permitted. For service purposes, cleaning of the pilot circuit can be done only by a certified repair shop to ensure air quality standards are not exceeded.

FUEL LEVEL

A fuel level test can be performed on some models if the drain hose fitting is accessible. Be sure to re-attach the bowl drain hose after performing the test. A fuel level test allows you to observe the height of the fuel in the float bowl without removing the carburetor. The fuel level can be observed with the engine either running or shut off, however, engine must run briefly to allow fuel level to stabilize..

1. Attach a clear line to drain fitting. Be sure line fits tightly on fitting. Position hose along side of carburetor as shown in your service manual.

FUEL PUMP

This ATV is equipped with a pressure regulated fuel pump (1-3 PSI). The pump is located under the left front fender of the machine.

To test the fuel pump:

1. Turn fuel off.
2. Disconnect impulse line from pump.
3. Connect Mity-Vact(PN 2870975) to the impulse line fitting on the pump.
4. Apply 5 inches (Hg) vacuum to the pump fitting. The diaphragm should hold vacuum indefinitely. If fuel is present in the impulse line or vacuum chamber of the pump, the diaphragm is ruptured. The pump diaphragms must be replaced.

FUEL PUMP DISASSEMBLY

1. Remove the screws from the pump diaphragm cover. Note the location of the two longer screws.
2. Remove the diaphragm cover gasket, diaphragm, and valve body gasket.
3. Remove the outlet check valve cover, diaphragm, and gasket.

FUEL PUMP INSPECTION/ASSEMBLY

1. Inspect inlet and outlet check valves for cracks, warpage or damage. Inspect the diaphragms for cracks, holes or swelling.
2. To clean the valves or pump body, remove the set screw and washer. Remove the valve and wash with soap and water. Carburetor cleaner may be used to clean the pump body when the check
valves are removed. CAUTION: Some carburetor cleaners are very caustic and should not be used to clean the non-metal parts of the fuel pump.
3. Check the sealing surfaces of the pump body and covers. Carefully remove all traces of old gasket and check the surfaces for damage. Replace diaphragms and gaskets as a set.
4. Reassemble the pump in the reverse order of disassembly. Tighten all screws evenly.

FUEL LEVEL

A fuel level test can be performed on some models if the drain hose fitting is accessible. Be sure to re-attach the bowl drain hose after performing the test. A fuel level test allows you to observe the height of the fuel in the float bowl without removing the carburetor. The fuel level can be observed with the engine either running or shut off, however, engine must run briefly to allow fuel level to stabilize..

1. Attach a clear line to drain fitting. Be sure line fits tightly on fitting. Position hose along side of carburetor as shown.

CARBURETOR INSPECTION

1. Inspect jet needle and needle jet for wear. Look for discoloration, shiny spots, or an area that looks different than the rest of the needle. The middle to upper portion of the needle contacts the needle jet and is the most likely wear point. If jet needle shows signs of wear replace both the needle and needle jet to prevent a rich condition. TIP: Aworn needle jet is difficult to spot. To check,
slide a slightly larger new jet needle into the needle jet and hold it to a light source. Light will be visible between the needle and needle jet if it is worn.

CARBURETOR ASSEMBLY

Inspect the diaphragm (A) for holes, deterioration, or damage. Make sure the diaphragm is pliable but not swollen. The diaphragm should fit properly in the carburetor body. Replace diaphragm assembly if diaphragm is damaged.

2. Inspect the inlet needle tapered surface for any sign of wear or damage. Be sure the spring loaded pin is freemoving and returns freely when pushed. The inlet needle and seat should be
pressure tested after assembly.
3. Replace parts in proper order. The spring seat washer (B) is stepped and must be placed on TOP of “E” Clip (C). Spacer washer (D) must be installed below the E-Clip. Refer to parts manual
for more information.
4. Be sure the tab (E) on outer edge of diaphragm is positioned properly in the carburetor body.

STATOR, FLYWHEEL AND STARTER DRIVE INSTALLATION

NOTE: The stator, flywheel, starter drive, and recoil can be assembled with the engine in the frame.

Stator

1. Apply a light film of grease to the crankshaft seal. Apply molybdenum disulfide grease or assembly lubricant to the crankshaft bushing.
2. Install a new O-Ring in the oil passage recess in the crankcase.
3. Apply 3 Bond 1215 (PN 2871557) or an equivalent sealer to the stator plate outer surface and install a new O-Ring.
4. Install the stator plate being careful not todamage the seal. Align timing reference marks on the plate and crankcase. Be sure the plate is fully seated. NOTE: This is a static timingmark. Strobe timing should be performed after start up.
5. Torque bolts evenly to specification.
6. Seal stator wire grommet with CrankcaseSealant (PN 2871557) or equivalent sealer.

Flywheel

1. Install flywheel, washer, and nut. Torque flywheel to specification.

Starter

1. Be sure the washer is positioned on the back of the drive gear.
2. Apply starter drive grease to the drive bushing in the crankcase and all moving surfaces of the starter drive mechanism. Install the starter drive.
3. Install recoil housing gasket and recoil housing.

DRIVE CHAIN ADJUSTMENT, CONCENTRIC SWINGARM

CAUTION: Never adjust or operate the vehicle with the rear drive chain too loose or too tight as severe damage to the transmission and drive components can result.

Break-In: It is extremely important tomaintain proper chain tension to ensure the best possible chain life. There is a chain break-in period of approximately 100miles or two (2) tanks of fuel. During this time chain tension should be watched very closely and loads to the chain should be kept light.

Checking Deflection: Inspect chain deflection by slowly moving the ATV forward so any slack that may have previously been on the under part of the chain is now on the top side of the chain. The bottom part of the chain should be taught during inspection. Measure the chain deflection as shown in the diagram. Deflection should be approximately 3/8 in. (10 mm). After inspection, again slowly move the ATV forward until all the chain slack is on the top side of the chain and inspect the deflection. Repeat this procedure several times to check different spots on the chain.

The chain is correctly adjusted when the tightest portion of the chain itself has approximately 3/8in., (10 mm) of deflection. It’s a common characteristic of any chain to have one or more tight spots in the chain. Therefore, it is extremely important to check chain deflection in several areas of the chain to ensure deflection is correct at the tightest point.

MAIN AIR FILTER CLEANING

It is advisable to replace the filter when it is dirty. However, in an emergency it is permissible to clean the main filter if you observe the following practices.

Never immerse the filter in water since dirt can be transferred to the clean air side of the filter.
If compressed air is used never exceed a pressure of 40PSI. Always use a dispersion type nozzle to prevent filter damage and clean from the inside to the outside.
Replace the air filter every 50 hours, and possibly more often in very dirty conditions.

AIR FILTER/PRE-FILTER SERVICE

It is recommended that the air filter and pre filter be replaced annually. When riding in extremely dusty conditions, replacement is required more often. The pre filter should be cleaned before each ride using the following procedure:

1. Lift up on the rear of the seat.
2. Pull the seat back and free of the tabs. NOTE: When reinstalling seat, make sure the slots in the seat engage the tabs in the fuel tank.
3. Remove clips (A) from air box cover and remove cover. Inspect the gasket. It should adhere tightly to the cover and seal all the way around.

SPARK PLUG FOULING

Spark plug cap loose or faulty
Choke cable adjustment or plunger/cable sticking
Foreign material on choke plunger seat or plunger
Incorrect spark plug heat range or gap
Carburetor inlet needle and seat worn
Jet needle and/or needle jet worn or improperly adjusted
Excessive carburetor vibration (loose or missing needle jet locating pins)
Loose jets in carburetor or calibration incorrect for altitude/temperature
Incorrect float level setting
PVT system calibrated incorrectly or components worn or mis-adjusted
Fuel quality poor (old) or octane too high
Low compression
Restricted exhaust
Weak ignition (loose coil ground, faulty coil, stator, or ETC switch)
ETC switch mis-adjusted
Restricted air filter (main or pre-cleaner) or breather system
Improperly assembled air intake system
Restricted engine breather system
Oil contaminated with fuel
Restricted oil tank vent

TROUBLESHOOTING

Engine Turns Over But Fails to Start

No fuel
Dirt in fuel line or filter
Fuel will not pass through fuel valve
Fuel pump inoperative/restricted
Tank vent plugged
Carb starter circuit
Engine flooded
Low compression (high cylinderleakage)
No spark (Spark plug fouled)

Engine Does Not Turn Over

Dead battery
Starter motor does not turn
Engine seized, rusted, or mechanical failure

Engine Runs But Will Not Idle

Restricted carburetor pilot system
Carburetor misadjusted
Choke not adjusted properly
Low compression
Crankcase breather restricted

Engine Idles But Will Not Rev Up

Spark plug fouled/weak spark
Broken throttle cable
Obstruction in air intake
Air box removed (reinstall all intake components)
Incorrect or restricted carburetor jetting
ETC switch limiting speed
Reverse speed limiter limiting speed
Carburetor vacuum slide sticking/diaphragm damaged
Incorrect ignition timing
Restricted exhaust system

Engine Has Low Power

Spark plug fouled
Cylinder, piston, ring, or valve wear or damage (check compression)
PVT not operating properly
Restricted exhaust muffler
Carburetor vacuum slide sticking/diaphragm damaged
Dirty carburetor

Piston Failure - Scoring

Lack of lubrication
Dirt entering engine through cracks in air filter or ducts
Engine oil dirty or contaminated

Excessive Smoke and Carbon Buildup

Excessive piston-to-cylinder clearance
Wet sumping
Worn rings, piston, or cylinder
Worn valve guides or seals
Restricted breather
Air filter dirty or contaminated

Low Compression

Decompressor stuck

Cylinder head gasket leak
No valve clearance or incorrectly adjusted
Cylinder or piston worn
Piston rings worn, leaking, broken, or sticking
Bent valve or stuck valve
Valve spring broken or weak
Valve not seating properly (bent or carbon accumulated on sealing surface)
Rocker arm sticking

Backfiring

ETC or speed limiter system malfunction
Fouled spark plug or incorrect plug or plug gap
Carburetion faulty - lean condition
Exhaust system air leaks
Ignition system faulty:

Spark plug cap cracked/broken Ignition coil faulty Ignition or kill switch circuit faulty, Ignition timing incorrect, Sheared flywheel key

Poor connections in ignition system
System wiring wet
Valve sticking
Air leaks in intake
Lean condition

COOLING SYSTEM TROUBLESHOOTING

Overheating

Low coolant level
Air in cooling system
Wrong type of coolant
Faulty pressure cap or system leaks
Restricted system (mud or debris in radiator fins or restriction to air flow, passages blocked in radiator, lines, pump, or water jacket)
Lean mixture (restricted jets, vents, fuel pump or fuel valve)
Fuel pump output weak
Restricted radiator (internally or cooling fins)
Water pump failure
Cooling system restriction
Cooling fan inoperative or turning too slowly (perform current draw test)


Complete list of Yamaha YFM & YSF service manuals available:

Yamaha Badger 80 Service Manual Repair 1992-2001 Yfm80
Yamaha Badger 80 Service Manual Repair 1985-1988 Yfm80
Yamaha Raptor 80 Service Manual Repair 2002-2008 Yfm80
2009-2010 Yamaha Raptor 90 YFM90RY YFM 90R RY 90RY Service Manual
2003-2005 Yamaha Yfm450 (yfm 450) Kodiak Service Manual
2006-2009 Yamaha Raptor Yfm700rv Service Manual (yfm700, Yfm 700 Rv)
2004-2006 Bruin 350, 400 Service Manual (yfm350Fa, Yfm 350 A, Yfm400Fa, Yfm 400)
1995-1999 Yamaha Yfm350 Service Repair Manual Big Bear (yfm 350)
1998-2001 Yamaha Yfm600 Grizzly Service Manual Yfm600 Grizzly
2002-2006 Yamaha Yfm660 (yfm 660) Grizzly Service Repair Manual
2000-2005 Yamaha Yfm400 (yfm 400) Kodiak Service Repair Manual
1999-2004 Yamaha Yfm250 (yfm 250) Xl Bear Tracker Service Manual Beartracker
2001-2005 Yamaha Yfm660 (yfm 660 R) Raptor Service Manual
2003-2005 Yamaha Yfm400 (yfm 400) Yfm4 Kodiak Service Manual
Yamaha Wolverine 350 Service Manual Repair 1995-2009 Yfm350
Yamaha Warrior Service Manual Repair 1987-2004 Yfm350
Yamaha Grizzly 125 Service Manual Repair Yfm125
Yamaha Raptor 50 Service Manual Repair 2004-2008 Yfm50
Yamaha Big Bear 400 Service Manual Repair 2007-2010 Yfm40fb
Yamaha Big Bear 400 Service Manual Repair 2000-2003 Yfm400
Yamaha Grizzly 450 Service Manual Repair 2007-2009 Yfm45fg
Yamaha Raptor 350 Service Manual Repair Yfm350
Yamaha Raptor 250 Service Manual Repair 2008 Yfm250
Yamaha Wolverine 450 Service Manual Repair 2006-2010 Yfm450
Yamaha Grizzly 550 700 Service Manual Repair 2009-2010
Yamaha Breeze 125 Service Manual Repair 1989-2004 Yfa1
Yamaha Grizzly 700 Service Manual Repair 2007-2008 Yfm7fg
Yamaha Blaster YSF200 YSF-200 Service Manual 1988 2005


1985-2010 Yamaha YFM & YSF Service Manuals, Owner's Service Manual, Repair Manual, 1985, 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, Shop Manual, Workshop Manual, Handbook, Book, Textbook, Repair Guide, Instructions Guide