engine YAMAHA YFM350R-W 2012 Workshop Manual

9-1
9
EBU25860
CLEANING AND STORAGE
EBU28191Cleaning Frequent, thorough cleaning of your ATV will not
only enhance its appearance but will improve its
general performance and extend the useful life of
many components.
1. Before cleaning the ATV:
a. Block off the end of the exhaust pipe to
prevent water entry. A plastic bag and
strong rubber band may be used.
b. Make sure the spark plug and all filler caps
are properly installed.
c. Make sure the steering lock cap is properly
installed.
2. If the engine case is excessively greasy, apply
degreaser with a paint brush. Do not apply de-
greaser to the chain, sprockets or wheel ax-
les.
3. Rinse the dirt and degreaser off with a garden
hose. Use only enough pressure to do the job.
WARNING! Wet brakes may have reduced
stopping ability, increasing the chance of
an accident. Test the brakes after washing.
Apply the brakes several times at slowspeeds to let friction dry out the linings.
[EWB02311]
NOTICE: Excessive water pressure
may cause water seepage and deteriora-
tion of wheel bearings, brakes, transmis-
sion seals and electrical devices. Many
expensive repair bills have resulted from
improper high-pressure detergent applica-
tions such as those available in coin-oper-
ated car washers.
[ECB00711]
4. Once most of the dirt has been hosed off,
wash all surfaces with warm water and mild,
detergent-type soap. An old toothbrush or bot-
tle brush is handy for hard-to-reach places.
5. Rinse the ATV off immediately with clean wa-
ter and dry all surfaces with a chamois, clean
towel or soft absorbing cloth.
6. Dry the chain and lubricate it to prevent it from
rusting.
7. Clean the seat with a vinyl upholstery cleaner
to keep the cover pliable and glossy.
8. Automotive type wax may be applied to all
painted and chrome plated surfaces. Avoid
combination cleaner-waxes. Many contain
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9-2
9 abrasives which may mar the paint or protec-
tive finish. When finished cleaning, start the
engine and let it idle for several minutes.
EBU25933Storage Short-term
Always store your ATV in a cool, dry place and, if
necessary, protect it against dust with a porous
cover. NOTICE: Storing the ATV in a poorly ven-
tilated room or covering it with a tarp while it is
still wet, will allow water and humidity to seep
in and cause rust. To prevent corrosion, avoid
damp cellars, stables (because of the presence
of ammonia) and areas where strong chemi-
cals are stored.
[ECB00721]
Long-term
Before storing your ATV for several months:
1. Follow all the instructions in the “Cleaning”
section of this chapter.
2. Turn the fuel cock lever to “OFF”.
3. Drain the carburetor float chamber by loosen-
ing the drain bolt; this will prevent fuel deposits
from building up. Pour the drained fuel into the
fuel tank.4. Fill up the fuel tank and add fuel stabilizer (if
available) to prevent the fuel from deteriorat-
ing.
5. Perform the following steps to protect the cyl-
inder, piston rings, etc. from corrosion.
a. Remove the spark plug cap and spark
plug.
b. Pour a teaspoonful of engine oil into the
spark plug bore.
c. Install the spark plug cap onto the spark
plug, and then place the spark plug on the
cylinder head so that the electrodes are
grounded. (This will limit sparking during
the next step.)
d. Turn the engine over several times with the
starter. (This will coat the cylinder wall with
oil.)
e. Remove the spark plug cap from the spark
plug, and then install the spark plug and
the spark plug cap.
6. Lubricate all control cables and the pivoting
points of all levers and pedals. Specified amount:
7.5 ml of stabilizer to each liter of fuel (or 1
oz of stabilizer to each gallon of fuel)U10P70E0.book Page 2 Thursday, July 21, 2011 8:51 AM

10-1
10
EBU25961
SPECIFICATIONS
Dimensions:Overall length:
1780 mm (70.1 in)
Overall width:
1095 mm (43.1 in)
Overall height:
1095 mm (43.1 in)
Seat height:
820 mm (32.3 in)
Wheelbase:
1210 mm (47.6 in)
Ground clearance:
115 mm (4.5 in)
Minimum turning radius:
3100 mm (122 in)Weight:With oil and fuel:
184.0 kg (406 lb)Engine:Engine type:
Air cooled 4-stroke, SOHC
Cylinder arrangement:
Forward-inclined single cylinder
Displacement:
349 cm³
Bore × stroke:
83.0 × 64.5 mm (3.27 × 2.54 in)Compression ratio:
9.20 : 1
Starting system:
Electric starter
Lubrication system:
Wet sump
Engine oil:Recommended brand:
YAMALUBE
Type:
SAE 5W-30, 10W-30, 10W-40, 15W-40, 20W-40 or 20W-
50
Recommended engine oil grade:
API service SG type or higher, JASO standard MA0 10 30 50 70 90 110 130 ˚F
–20 –10 0 10 20 30 40 50 ˚CSAE 5W-30
SAE 10W-30
SAE 10W-40
SAE 15W-40
SAE 20W-40SAE 20W-50
U10P70E0.book Page 1 Thursday, July 21, 2011 8:51 AM

10-2
10
Engine oil quantity:
Without oil filter element replacement:
2.50 L (2.64 US qt, 2.20 Imp.qt)
With oil filter element replacement:
2.60 L (2.75 US qt, 2.29 Imp.qt)Air filter:Air filter element:
Wet elementFuel:Recommended fuel:
Regular unleaded gasoline only
Fuel tank capacity:
9.0 L (2.38 US gal, 1.98 Imp.gal)
Fuel reserve amount:
2.7 L (0.71 US gal, 0.59 Imp.gal)Carburetor:Type × quantity:
BSR36 x 1Spark plug (s):Manufacturer/model:
NGK/DR8EA
Spark plug gap:
0.6–0.7 mm (0.024–0.028 in)Clutch:Clutch type:
Wet, multiple-disc
Operation:
Left hand operationTransmission:Primary reduction system:
Spur gearPrimary reduction ratio:
76/24 (3.166)
Secondary reduction system:
Chain drive
Secondary reduction ratio:
38/13 (2.923)
Transmission type:
Constant mesh 6-speed.forward, 1-speed.reverse
Operation:
Left foot operation
Gear ratio:
1st:
36/16 (2.685)
2nd:
33/20 (1.969)
3rd:
29/23 (1.504)
4th:
27/26 (1.239)
5th:
25/28 (1.065)
6th:
23/29 (0.946)
Forward gear:
20/27 × 29/18
Reverse gear:
33/16 × 33/10 (6.806)
Chassis:Frame type:
Steel tube frame
Caster angle:
6.0 °
U10P70E0.book Page 2 Thursday, July 21, 2011 8:51 AM

INDEX
AAccessories and loading ................................................ 6-8
Air filter element, cleaning ............................................ 8-15
Auxiliary light bulb ........................................................ 8-44BBattery .......................................................................... 8-38
Brake and clutch levers, checking and lubricating ....... 8-33
Brake and shift pedals, checking and lubricating ......... 8-34
Brake fluid, changing ................................................... 8-25
Brake fluid level, checking ........................................... 8-23
Brake lever ..................................................................... 4-6
Brake lever free play, checking the front ...................... 8-25
Brake light switches ..................................................... 8-27
Brake pads, checking the front and rear ...................... 8-22
Brake pedal .................................................................... 4-6
Brake pedal height, checking ....................................... 8-25
Brakes .......................................................................... 8-22
Brakes, front and rear .................................................... 5-3CCables, checking and lubricating ................................. 8-32
Carburetor, adjusting ................................................... 8-20
Chassis fasteners .......................................................... 5-6
Cleaning ......................................................................... 9-1
Clutch lever .................................................................... 4-6
Clutch lever free play, adjusting ................................... 8-28DDrive chain ..................................................................... 5-4
Drive chain, lubricating ................................................. 8-32Drive chain slack .......................................................... 8-29
Drive select lever ........................................................... 4-8
Drive select lever and driving in reverse ........................ 6-3
EEngine break-in .............................................................. 6-6
Engine, cold start ........................................................... 6-1
Engine idling speed ..................................................... 8-20
Engine oil ....................................................................... 5-3
Engine oil and oil filter element .................................... 8-11
Engine, starting a warm ................................................. 6-3
Engine stop switch ......................................................... 4-3FFuel ......................................................................... 4-9, 5-3
Fuel cock ..................................................................... 4-11
Fuel tank cap ................................................................. 4-9
Fuses, replacing .......................................................... 8-40HHandlebar switches ....................................................... 4-3
Hazard switch ................................................................ 4-4
Headlight beam ............................................................ 8-41
Headlight bulb .............................................................. 8-41
High beam indicator light ............................................... 4-2
Horn switch .................................................................... 4-4IIdentification numbers .................................................. 11-1
Indicator lights ................................................................ 4-2
Instruments, lights and switches .................................... 5-6
U10P70E0.book Page 1 Thursday, July 21, 2011 8:51 AM