Page 53 of 91
PERIODIC MAINTENANCE AND MINOR REPAIR
6-11
6
NOTE:@ l
If water is added, have a Yamaha
dealer check the antifreeze con-
tent of the coolant as soon as pos-
sible.
l
Have a Yamaha dealer change
the coolant every two years.
l
The radiator fan operation is com-
pletely automatic. It is switched on
or off according to the coolant tem-
perature in the radiator.
@
EAU00630
Carburetor adjustmentThe carburetors are important parts of
the engine and require very sophisti-
cated adjustment. Most adjustments
should be left to a Yamaha dealer who
has the professional knowledge and
experience to do so. However, the idle
speed may be adjusted by the owner
as part of routine maintenance.
EC000095
CAUTION:@ The carburetors were set at the
Yamaha factory after many tests. If
they are changed, poor engine per-
formance and damage may result. @
EAU01168
Idle speed adjustmentNOTE:@ A diagnostic tachometer must be used
for this procedure. @1. Attach the tachometer. 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 quick-
ly responds to the throttle.
1. Reservoir tank capE_4YP_Periodic.fm Page 11 Wednesday, October 6, 1999 10:05 AM
Page 72 of 91
PERIODIC MAINTENANCE AND MINOR REPAIR
6-30
6
5. Engine overheating
EW000070
WARNING
@ Do not remove the radiator cap when the engine and radiator are hot. Scalding hot fluid and steam may be blown
out under pressure, which could cause serious injury. Open the radiator cap as follows. Wait until the engine has
cooled. Remove the radiator cap stopper by removing the screw. Place a thick rag like a towel over the radiator cap
and slowly rotate the cap counterclockwise to the detent. This procedure allows any residual pressure to escape.
When the hissing sound has stopped, press down on the cap while turning counterclockwise and remove it. @NOTE:@ If it is difficult to get the recommended coolant, tap water can be temporarily used, provided that it is changed to the recom-
mended coolant as soon as possible. @
Wait until the
engine has cooled.
Check the coolant level in the
reservoir tank and/or radiator.
Level is OK.Level is low, check the
cooling system for leakage.
No
leakage.Leakage.
Ask a Yamaha dealer to inspect
and repair the cooling system.Add coolant. (See NOTE.)
Restart the engine. If the engine overheats again, ask a
Yamaha dealer to inspect and repair the cooling system.
E_4YP_Periodic.fm Page 30 Wednesday, October 6, 1999 10:05 AM
Page 82 of 91
SPECIFICATIONS
8-2
8
Final gear oil
Type SAE80API “GL-4” Hypoid Gear
Oil
Quantity 0.2 L
Radiator
capacity (including all routes) 2.9 L
Air filterDry type element
Fuel
Type Regular unleaded gasoline
Fuel tank capacity 18 L
Reserve amount 3.5 L
Carburetor
Type ´ quantity BDS28 ´ 4
Manufacturer MIKUNI
Spark plug
Manufacturer/Type NGK / DPR7EA-9 or
DENSO / X22EPR-U9
Gap 0.8 ~ 0.9 mm
Clutch typeWet, multiple-disc
Transmission
Primary reduction system Spur gear
Primary reduction ratio 1.667
Secondary reduction system Shaft drive
Secondary reduction ratio 2.567Transmission type Constant mesh 5-speed
Operation Left foot operation
Gear ratio
1st 2.438
2nd 1.579
3rd 1.160
4th 0.906
5th 0.750
Chassis
Frame type Double cradle
Caster angle 30°
Trail 126 mm
Tires
Front
Type Tubeless
Size 150/80-16 71H
Manufacturer /
modelDunlop / D404F
Rear
Type Tubeless
Size 150/90B15M/C 74H
Manufacturer /
modelDunlop / D404
E_4YP_Spec.fm Page 2 Wednesday, October 6, 1999 10:06 AM
