Front wheel YAMAHA TTR50 2006 Owners Manual

CHAPTER 4ENGINE
FRONT FENDER, SEAT ASSEMBLY
AND FUEL TANK .......................................4-1
MUFFLER ...................................................4-3
CARBURETOR ...........................................4-4
CYLINDER HEAD .....................................4-10
CAMSHAFT AND ROCKER ARMS .........4-15
VALVES AND VALVE SPRINGS .............4-18
CYLINDER AND PISTON .........................4-23
CLUTCH ....................................................4-29
SHIFT SHAFT ...........................................4-37
OIL PUMP .................................................4-39
AC MAGNETO AND
STARTER CLUTCH ..................................4-42
ENGINE REMOVAL ..................................4-47
CRANKCASE AND CRANKSHAFT .........4-51
SHIFT FORK, SHIFT CAM AND
TRANSMISSION .......................................4-54
CHAPTER 5
CHASSIS
FRONT WHEEL AND REAR WHEEL ........5-1
HANDLEBAR ............................................5-10
STEERING AND
FRONT SUSPENSION .............................5-13
SWINGARM ..............................................5-17
CHAPTER 6
ELECTRICAL
ELECTRICAL COMPONENTS AND
WIRING DIAGRAM .....................................6-1
IGNITION SYSTEM .....................................6-2
ELECTRIC STARTING SYSTEM ...............6-6
CHARGING SYSTEM ...............................6-14
CARBURETOR HEATING SYSTEM ........6-16
MAINTENANCE RECORD .......................6-20

GEN
INFO
1 - 13
CLEANING AND STORAGE
EC1B0000
CLEANING AND STORAGE
EC1B1000
CLEANING
Frequent cleaning of your machine will
enhance its appearance, maintain good overall
performance, and extend the life of many com-
ponents.
1. Before washing the machine, block off the
end of the exhaust pipe to prevent water
from entering.
2. If the engine is excessively greasy, apply some degreaser to it with a paint brush. Do
not apply degreaser to the chain, sprock-
ets, or wheel axles.
3. Rinse the dirt and degreaser off with a gar- den hose; use only enough pressure to do
the job.
CAUTION:
Excessive hose pressure may cause water
seepage and contamination of wheel bear-
ings, front forks, brakes and transmission
seals. Many expensive repair bills have
resulted from improper high pressure
detergent applications such as those avail-
able in coin-operated car washers.
4. After the majority of the dirt has been hosed off, wash all surfaces with warm
water and a mild detergent. Use an old
toothbrush to clean hard-to-reach places.
5. Rinse the machine off immediately with clean water, and dry all surfaces with a soft
towel or cloth.
6. Immediately after washing, remove excess water from the chain with a paper towel
and lubricate the chain to prevent rust.
7. Clean the seat with a vinyl upholstery cleaner to keep the cover pliable and
glossy.
8. Automotive wax may be applied to all
painted or chromed surfaces. Avoid combi-
nation cleaner-waxes, as they may contain
abrasives.
9. After completing the above, start the engine and allow it to idle for several min-
utes.
EC182001
STORAGE
If your machine is to be stored for 60 days or
more, some preventive measures must be
taken to avoid deterioration. After cleaning the
machine thoroughly, prepare it for storage as
follows:
1. Drain the fuel tank, fuel lines, and the car-
buretor float bowl.
2. Remove the spark plug, pour a tablespoon of SAE 10W-30 motor oil in the spark plug
hole, and reinstall the plug. Set the engine
stop switch to “”, turn the engine over
several times with starter. (This will coat
the cylinder walls with oil.)
3. Remove the drive chain, clean it thoroughly with solvent, and lubricate it. Reinstall the
chain or store it in a plastic bag tied to the
frame.
4. Lubricate all control cables.
5. Block the frame up to raise the wheels off the ground.
6. Tie a plastic bag over the exhaust pipe out-
let to prevent moisture from entering.
7. If the machine is to be stored in a humid or salt-air environment, coat all exposed
metal surfaces with a film of light oil. Do not
apply oil to rubber parts or the seat cover.
NOTE:
Make any necessary repairs before the
machine is stored.

SPEC
2 - 3
Suspension:
Front suspension Telescopic fork
Rear suspension Swingarm (monocross suspension)
Shock absorber:
Front shock absorber Coil spring
Rear shock absorber Coil spring/oil damper
Wheel travel: Front wheel travel 96.0 mm (3.78 in)
Rear wheel travel 71.0 mm (2.80 in)
Electrical: Ignition system CDI
Charging system AC magneto
GENERAL SPECIFICATIONS

SPEC
2 - 11
CHASSIS
Item Standard Limit
Steering system: Steering bearing type Angular bearing ----
Front suspension: Front fork travel 96 mm (3.78 in) ----
Spring rate K1 7.95 N/mm (0.81 kgf/mm, 45.39 lb/in)----
K2 10.50 N/mm (1.07 kgf/mm, 59.96 lb/in) ----
Optional spring/spacer No ----
Inner tube outer diameter 21.7 mm (0.85 in) ----
Rear suspension: Shock absorber travel 47 mm (1.85 in) ----
Spring free length 114 mm (4.49 in) ----
Fitting length 110 mm (4.33 in) ----
Spring rate, STD K = 29.0 N/mm (2.96 kg/mm, 166 lb/in)----
Optional spring No ----
Swingarm: Swingarm free play limit End ---- 1.0 mm (0.0394 in)
Side clearance ---- 0.3 mm (0.0118 in)
Wheel: Front wheel type Spoke wheel ----
Rear wheel type Spoke wheel ----
Front rim size/material 10 × 1.40/steel ----
Rear rim size/material 10 × 1.40/steel ----
Rim runout limit: Radial ---- 2.0 mm (0.08 in)
Lateral ---- 2.0 mm (0.08 in)
Drive chain: Type/manufacturer 420/KMC ----
Number of links 79 links + joint ----
Chain slack 35 ~ 45 mm (1.38 ~ 1.77 in) ----
Chain length (15 links) ---- 194.3 mm (7.65 in)
MAINTENANCE SPECIFICATIONS

SPEC
2 - 13
NOTE:
1.First, tighten the ring nut approximately 38 Nm (3.8 m · kg, 27 ft · lb) by using the lower ring nut
wrench and turn the steering right and left a few times; then loosen the lower ring nut completely.
2.Retighten the lower ring nut 4 Nm (0.4 m · kg, 2.9 ft · lb).
Part to be tightened Thread size Q
’ty Tightening torque
Nm m ·kg ft ·lb
Engine mounting: Engine and frame (front upper side) M8 × 1.25 1 30 3.0 22
Engine and frame (rear upper side) M8 × 1.25 1 30 3.0 22
Engine and frame (rear lower side) M10 × 1.25 1 48 4.8 35
Engine bracket and frame M8 × 1.25 2 30 3.0 22
Front wheel axle and front wheel axle nut M12 × 1.25 1 35 3.5 25
Front brake camshaft lever and front brake
camshaft M6
× 1.0 1 7 0.7 5.1
Front brake cable locknut M8 × 1.25 1 16 1.6 11
Front wheel nipple (spoke) —28 2 0.2 1.4
Rear wheel nipple (spoke) —28 2 0.2 1.4
Rear wheel axle and rear wheel axle nut M12 × 1.25 1 60 6.0 43
Rear brake camshaft lever and rear brake
camshaft M6
× 1.0 1 7 0.7 5.1
Rear wheel drive hub and rear wheel sprocket M8 × 1.25 4 25 2.5 18
Drive chain puller locknut M6 × 1.0 2 7 0.7 5.1
Upper bracket and handlebar M10 × 1.25 2 32 3.2 23
Steering stem nut M22 × 1.0 1 110 11.0 80
Lower ring nut M25 1 Refer to NOTE.
Upper bracket and lower bracket M10 × 1.25 2 32 3.2 23
Inner tube assembly and front fork guard M6 × 1.0 4 7 0.7 5.1
Pivot shaft and nut M10 × 1.25 1 35 3.5 25
Rear shock absorber and frame M10 × 1.25 1 30 3.0 22
Rear shock absorber and swingarm M10 × 1.25 1 30 3.0 22
Drive chain guide and swingarm M6 × 1.0 2 7 0.7 5.1
Drive chain support and swingarm M6 × 1.0 3 7 0.7 5.1
Drive chain guard and swingarm M6 × 1.0 2 7 0.7 5.1
Upper bracket and front fender M6 × 1.0 2 7 0.7 5.1
Fuel tank and fuel cock M6 × 1.0 2 7 0.7 5.1
Fuel tank and frame M6 × 1.0 2 7 0.7 5.1
Air scoop and fuel tank M6 × 1.0 2 7 0.7 5.1
Seat assembly and frame M6 × 1.0 2 7 0.7 5.1
Seat and rear fender M6 × 1.0 3 7 0.7 5.1
Seat and side covers M6 × 1.0 4 7 0.7 5.1
Footrest, under cover and engine M8 × 1.25 4 30 3.0 22
Sidestand and sidestand bracket M10 × 1.25 1 40 4.0 29
MAINTENANCE SPECIFICATIONS

3 - 1
INSPADJ
MAINTENANCE INTERVALS
EC300000
REGULAR INSPECTION AND ADJUSTMENTS
MAINTENANCE INTERVALS
The following schedule is intended as a general guide to maintenance and lubrication. Bear in mind
that such factors as weather, terrain, geographical location, and individual usage will alter the
required maintenance and lubrication intervals. If you are a doubt as to what intervals to follow in
maintaining and lubricating your machine, consult your Yamaha dealer.
No. ITEM CHECKS AND
MAINTENANCE JOBS WHICH-
EVER
COMES
FIRST INITIAL EVERY
month 1 6 12
hours 30 60 120
1 * Fuel line Check fuel hoses for cracks or damage.
Replace if necessary.
√

√
2 Spark plug Check condition.
Adjust gap and clean.
√

√
3 * Valve clearance Check and adjust valve clearance when engine is
cold.
√

4 * Air filter element Clean with solvent.
Replace if necessary.
√

√
5 * Breather system Check ventilation hose for cracks or damage.
Replace if necessary.
√

√
√
6 * Carburetor Check engine idling speed and starter operation.
Adjust if necessary.
√

√
√
7 Exhaust system Check for leakage.
Tighten if necessary.
Replace gasket if necessary.
√

√
8 Engine oil Change (warm engine before draining). √
√
√
9 * Clutch Check operation.
Adjust if necessary.
√

√
√
10 * Front brake Check operation.
Adjust brake lever free play and replace brake shoes
if necessary.
√

√
√
11 * Rear brake Check operation.
Adjust brake pedal free play and replace brake shoes
if necessary. √

√
√
12 * Wheels Check runout, spoke tightness and for damage.
Tighten spokes if necessary.
√

√
√
13 * Tires Check tread depth and for damage.
Replace if necessary.
Check air pressure.
Correct if necessary.
√

√
14 * Wheel bearings Check bearings for smooth operation.
Replace if necessary.
√

√
15 * Swingarm Check swingarm pivoting point for play.
Correct if necessary.
Lubricate with lithium soap based grease. √

√
√
16 Drive chain Check chain slack/alignment and condition.
Adjust and lubricate chain. Every ride
17 * Steering bearings Check bearing assemblies for looseness.
Lubricate with lithium soap based grease every
120 hours or 12 months (whichever comes first).
√

√
18 Brake lever pivot
shaft Apply lithium soap based grease lightly.
√
√
√
19 Brake pedal pivot
shaft Apply lithium soap based grease lightly.
√
√
√
3

3 - 3
INSPADJ
PRE-OPERATION INSPECTION AND MAINTENANCE
PRE-OPERATION INSPECTION AND MAINTENANCE
Before riding for break-in operation, practice or a race, make sure the machine is in good operating
condition.
Before using this machine, check the following points.
GENERAL INSPECTION AND MAINTENANCE
Item Routine Page
Fuel Check that a fresh gasoline is filled in the fuel tank. Check the fuel line
for leakage. P.1-11
Engine oil Check that the oil level is correct. Check the crankcase for leakage. P.3-7 ~ 9
Throttle Check for proper throttle cable operation. P.3-4 ~ 5
Brakes Check the play of front and rear brake and effect of front and rear
brake. P.3-14 ~ 15
Drive chain Check chain slack and alignment. Check that the chain is lubricated
properly. P.3-16 ~ 18
Wheels and tires Check pressure/runout/spoke tightness/bead stopper/axle nuts. P.3-19 ~ 20
Steering Check that the handlebar can be turned smoothly and have no exces-
sive play. P.3-20 ~ 21
Front forks and rear
shock absorber assembly Check that they operate smoothly and there is no oil leakage. P.3-18
Cables (wires) Check that the throttle cable move smoothly. Check that they are not
caught when the handlebars are turned. —
Muffler Check that the muffler is tightly mounted and has no cracks. P.4-3
Sprocket Check that the driven sprocket tightening nut is not loose. P.3-15
Lubrication Check for smooth operation. Lubricate if necessary. P.3-22
Spark plug Check color/condition. P.3-23
Fittings/fasteners Check all – tighten as necessary. P.2-13
Lead connectors Check that the AC magneto, CDI unit, and ignition coil are connected
tightly. P.1-5

3 - 15
INSPADJ
FRONT BRAKE SHOE INSPECTION
1. Inspect:
Brake shoe lining wear limit
Brake shoe lining wear limit checking
steps:
 Fully pull in the brake lever and hold it in
position.
 Then check the brake shoe wear indicator
1 is within the wear limit a.
Outside the limit → Replace the brake
shoes.
Refer to “FRONT WHEEL AND REAR
WHEEL ” section in the CHAPTER 5.
a
1
REAR BRAKE SHOE INSPECTION
1. Inspect:
Brake shoe lining wear limit
Brake shoe lining wear limit checking
steps:
 Fully push down the brake pedal and hold
it in position.
 Then check the brake shoe wear indicator
1 is within the wear limit a.
Outside the limit → Replace the brake
shoes.
Refer to “FRONT WHEEL AND REAR
WHEEL ” section in the CHAPTER 5.
a 1
SPROCKETS INSPECTION
1. Inspect:
Sprocket teeth a
Excessive wear → Replace.
NOTE:
Replace the drive, driven sprockets and drive
chain as a set.
FRONT BRAKE SHOE INSPECTION/
REAR BRAKE SHOE INSPECTION/SPROCKETS INSPECTION

3 - 18
INSPADJDRIVE CHAIN SLACK ADJUSTMENT/
FRONT FORK INSPECTION/REAR SHOCK ABSORBER INSPECTION
NOTE:
Turn the adjuster so that the chain is in line
with the sprocket, as viewed from the rear.
CAUTION:
Too small chain slack will overload the
engine and other vital parts; keep the
slack within the specified limits.
 Tighten the wheel axle nut while pushing
down the drive chain.
T R..
Axle nut:
60 Nm (6.0 m  kg, 43 ft  lb)
 Tighten the locknuts.
T R..
Locknut:
7 Nm (0.7 m  kg, 5.1 ft  lb)
EC36C000
FRONT FORK INSPECTION
1. Inspect:
Front fork smooth action
Operate the front brake and stroke the
front fork.
Unsmooth action → Repair or replace.
EC36K000
REAR SHOCK ABSORBER INSPECTION
1. Inspect:
Swingarm smooth action
Abnormal noise/unsmooth action →
Grease the pivoting points or repair the
pivoting points.
Damage/oil leakage → Replace.

3 - 20
INSPADJWHEEL INSPECTION/
STEERING HEAD INSPECTION AND ADJUSTMENT
2. Inspect:
Bearing free play
Exist play → Replace.
STEERING HEAD INSPECTION AND
ADJUSTMENT
1. Elevate the front wheel by placing a suit-
able stand under the engine.
2. Check:
Steering head
Grasp the bottom of the forks and gently
rock the fork assembly back and forth.
Free play → Adjust the steering head.
3. Check: Steering smooth action
Turn the handlebar lock to lock.
Unsmooth action → Adjust the steering
head.
4. Adjust:
Steering head
Steering ring nut adjustment steps:
 Remove the front fender 1.
 Remove the handlebar 2, upper bracket
bolts 3, steering stem nut 4 and upper
bracket 5.
1
4
3
52