Engine Idle Speed; Radiator Coolant; Cooling System - Honda CRF450R 2017 Manual

ENGINE IDLE SPEED
NOTE:
• The engine must be warm for accurate idle speed
inspection.
• When inspecting the engine idle speed, make sure
that the fast idle knob is pushed fully in.
• Use a tachometer with graduations of 50 rpm or
smaller that w ill accurately indicate a 50 rpm
change.
Start the engine and warm it up to coolant temperature
80°C (176°F).
Stop the engine and connect a tachometer according to
the tachometer manufacturer's operating instructions.
Start the engine and let it idle. Turn the fast idle knob [1]
to obtain the specified idle speed.
Turning the fast idle knob counterclockwise results in a
faster/higher idle speed.
Turning the fast idle knob clockwise results in a slower/
lower idle speed.
IDLE SPEED:2,000 ± 100 rpm
If engine idle speed can not adjust. check the fast idle
knob (page 7 -29).
RADIATOR COOLANT
Remove the radiator cap [1] (page 9-5).
Check the coolant level with the engine cold, it should
be up to the filler neck [2].
If the coolant level is low, add the coolant as required
(page 9-5).
NOTE:
• A coolant loss of 20 - 60 cm
3
(0.7 - 2.0 US oz)
through the overflow hose [3] is normal. If coolant
loss is more than this, inspect the cooling system.
Install the radiator cap.
COOLING SYSTEM
Remove the radiator grills (page 9-6).
Check the radiator air passages for clogging or
damage.
Straighten bent fins and remove insects, mud or other
obstructions with compressed air or low water pressure.
Replace the radiator if the air flow is restricted over
more than 20% of the radiating surface.
MAINTENANCE
3-17