Cooling System; Checking The Cooling Liquid Level - KTM 1998 400 R Owner's Handbook Manual

7
8
10 mm
when engine is cold

Cooling system

Coolant is circulated by a water pump located in the engine. When the
engine is cold the cooling liquid circulates only through the cylinder and
the cylinder head. After the engine has reached its operating temperature
(about 70°C, 158°F), the thermostat opens and the cooling liquid is also
pumped through both aluminum radiators.
Air blowing in through the radiators cools the cooling liquid. The slower
the speed of the motorcycle, the less the cooling liquid is cooled down.
Dirty radiator fins also reduce the cooling efficiency.
If little or no air blows through the radiators, for example when riding
6
through slow traffic or waiting at traffic lights, the coolant temperature will
rise. If the coolant temperature rises to 85° C (185° F), the fan
left radiator will switch on. This fan will provide additional air circulation
through the radiator thereby preventing the cooling system from overheating.
!
I
F THE RED COOLING LIQUID TEMPERATURE WARNING LAMP
MOST LIKELY BE DUE TO A DEFECT IN THE COOLING SYSTEM
DIATELY AND TURN OFF THE ENGINE
COOLING SYSTEM FOR LEAKS
CAUTION - SCALDING HAZARD! D
LIQUID IN THE COOLING SYSTEM
I ,
F POSSIBLE ALWAYS CHECK LEVEL OF COOLING LIQUID WHEN ENGINE IS COLD
HAVE TO OPEN THE RADIATOR CAP WHEN ENGINE IS HOT
CAP AND OPEN SLOWLY TO RELEASE PRESSURE
A mixture of 40% antifreezer and 60% water is used as cooling liquid.
How-ever, the anti-freeze protection must be at least -25° C (-13° F).
Aside from antifreezing protection, this mixture also provides great corro-
sion protection which is why it must not be replaced by pure water.
!
F
OR THE COOLING SYSTEM
C ). U
OOLANT SING LOWERGRADE ANTIFREEZE AGENTS
COOLANT FOAMING
Pressure induced by heating of the cooling liquid in the cooling system is
controlled by a valve in the radiator cap
to 120° C (248° F) is admissible, without fear of problems.

Checking the cooling liquid level

The cooling liquid should be 10 mm (0.4 in) above the cooling elements
when the engine is cold (cf. diagram). In the event of the cooling liquid
being drained, always fill the system before hand, then top off while the
engine is running.
I ,
F POSSIBLE ALWAYS CHECK LEVEL OF COOLING LIQUID WHEN ENGINE IS COLD
HAVE TO OPEN THE RADIATOR CAP WHEN ENGINE IS HOT
CAP AND OPEN SLOWLY TO RELEASE PRESSURE
CAUTION
. L
ET THE ENGINE COOL DOWN AND CHECK THE
. A
LSO CHECK IF THERE IS ENOUGH COOLING LIQUID
O NOT DRIVE ON
.
WARNING
.
CAUTION
, -
USE ONLY HIGH GRADE ANTIFREEZER
.
8
; a water temperature rising up
WARNING
.
7
on the
!
6
,
LIGHTS UP THIS WILL
. I , -
N THIS CASE STOP IMME
.
,
UNTIL THERE IS SUFFICIENT
. I
F YOU
,
USE A RAG TO COVER THE
!
(S A
HELL DVANCE
,
CAN CAUSE CORROSION AND
. I
F YOU
,
USE A RAG TO COVER THE
25