Yamaha RS Venture RST90Y Owner's Manual page 54

Periodic maintenance and adjustment
When the engine has cooled, place a thick
rag or towel over the coolant reservoir
cap, and slowly rotate the cap counter-
clockwise to the detent. This procedure al-
lows any residual pressure to escape.
When the hissing sound has stopped,
press down on the cap while turning coun-
terclockwise and remove it.
To check the coolant level
1. Place the snowmobile on a level surface
and apply the parking brake.
2. Open the shroud.
3. Check the coolant level in the coolant
reservoir when the engine is cold. If the
coolant level is below the "COLD LEVEL"
mark, add soft water until it reaches the
"COLD LEVEL" mark. (See the following
section "Replenishing the coolant" for
more details.) NOTICE: Hard water or
salt water is harmful to the engine
parts. You may use boiled or distilled
water, if soft water is not available.
Tap water can be used temporarily in
an emergency.
1. "COLD LEVEL" mark
Bleeding the cooling system
The cooling system must be bled of air if the
coolant reservoir becomes empty, if air can be
seen in the cooling system, or if there is a
cooling system leak. Consult a Yamaha deal-
er.
48
[ECS00491]
ECS00500
NOTICE
Operating the engine with an improperly
bled cooling system can cause overheat-
ing and severe engine damage.
Replenishing the coolant
1. Remove the coolant reservoir cap and
add coolant until it reaches the "COLD
LEVEL" mark.
1. "COLD LEVEL" mark
2. Coolant reservoir cap
Recommended antifreeze:
High-quality ethylene glycol antifreeze
containing corrosion inhibitors
Antifreeze and water mixing ratio:
3:2
Total amount:
5.40 L (5.71 US qt, 4.75 Imp.qt)
2. Start the engine and add coolant until the
coolant level does not go down, and then
stop the engine.
3. Fill the coolant reservoir with coolant until
it reaches the "COLD LEVEL" mark.