Yamaha Rx 1 User Guide

8-9
CD-04E
1. Loosen the carburetor clamps and remove all hoses
and cables, and then remove the carburetor. 
2. Pinch the fuel hose to prevent fuel flowing. 
3. Remove the float chamber and install the proper
main jet. 
4. Assemble by reversing the removal steps.
WARNING@ 
Make sure that all hoses and clamps are properly
installed. 
@ 
Standard main jet: 
# 135
Main jet 
1Mixture Condition
Small No. LeanWarm weather
High altitude
Large No. RichCold weather
Low altitude
U8FA11.book  Page 9  Thursday,...

8-10
ESU00157 
High altitude adjustments
Operating at high altitude reduces the performance of a
gasoline engine to about 3% for every 305 m (1,000 ft) of
elevation. This is because there is less air as altitude
increases. Less air means less oxygen available for com-
bustion.
Your snowmobile can be adjusted to overcome most of
the problems found in high altitude riding. Carburetor
adjustments are the most important. Less air at high alti-
tude makes the air/fuel ratio too rich, which can cause
poor...

8-11
ESU00349
Changing the engine oil
It is recommended to have a Yamaha dealer change the
engine oil.
WARNING@ 
Engine oil is extremely hot immediately after the
engine is turned off. Coming into contact with or get-
ting any engine oil on your clothes could result in
burns. 
@
CAUTION:@ 

Do not run the engine with too much or not
enough oil in the oil tank. Oil could spray out or
the engine could be damaged. 

Be sure to change the engine oil after the first
800 km (500 mi) of operation, and every...

8-12
8. Add 2.0 L (1.8 Imp qt, 2.1 US qt) of the recommended
engine oil to the oil tank, and then install and tighten
the oil level gauge/dipstick and the cylinder head cap.
9. Start the engine, warm it up for several minutes, and
then turn it off.
10. Add sufficient oil of the recommended type to raise it
to the “F” level mark on the oil level gauge/dipstick.
(See page 6-3 for checking procedure.)
CAUTION:@ 

When adding the engine oil, be careful not to fill
above the “F” level mark on the oil level...

8-13
ESU00161 
Cooling system
Air bleeding the cooling system
WARNING@ 

Do not remove the coolant reservoir cap when
the engine is hot. Scalding hot fluid and steam
may be blown out under pressure, which could
cause serious injury. 
When the engine has cooled, place a thick rag or
towel over the coolant reservoir cap, slowly rotate
the cap counterclockwise to the detent. This pro-
cedure allows any residual pressure to escape.
When the hissing sound has stopped, press
down on the cap while turning...

8-14
Coolant replenishment
1. Remove the coolant reservoir cap and pour the cool-
ant to the “COLD LEVEL” mark.
1“COLD LEVEL” mark 
2Coolant reservoir cap
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 to the “COLD
LEVEL” mark.
4. Install the coolant reservoir cap. Check for any cool-
ant leakage.
NOTE:@ If you find any leaks, consult a Yamaha dealer. @ 
Recommended coolant: 
High quality ethylene glycol...

8-15
ESU00166 
V-belt replacement
WARNING@ 
When installing the new V-belt, make sure it is posi-
tioned from 1.5 mm (0.06 in) above the edge of the
secondary sheave assembly to 0.5 mm (0.02 in)
below the edge a
. 
If not, the V-belt clutch engagement speed will be
changed. The snowmobile may move unexpectedly
when the engine is started. 
Adjust the V-belt position by removing or adding a
spacer 1
 on each adjusting bolt. 
Have a Yamaha dealer make this adjustment. 
@
CAUTION:@ 
As the V-belt wears,...

8-16
3. Pull 
3 the V-belt up over the secondary fixed sheave.
4. Remove the V-belt from the secondary sheave
assembly and primary sheave assembly. 
5. Put the new V-belt back on the secondary sheave
assembly only. Do not force the V-belt between the
sheaves; the secondary sliding and fixed sheave
must touch each other. Measure the V-belt position.
6. If the position is incorrect, adjust the V-belt position
by removing or adding a spacer 
4 on each adjusting
bolt 
5.
CD-06E
7. Tighten each adjusting...

8-17
8. Install the V-belt over the primary sheave assembly.
9. Rotate the secondary sliding sheave clockwise 
6
and push 
7 it so that it separates from the secondary
fixed sheave. 
10. Install the V-belt 
8 between the secondary sliding
and secondary fixed sheaves.
11. Install the drive guard.
WARNING@ 
Never run the engine with the V-belt or drive guard
removed. 
@
ESU00351
Checking the oil level of the drive chain hous-
ing
WARNING@ 
The engine, oil tank, brake disc, and coolant hoses
will be very...

8-18
3. Remove the dipstick and check that the oil is between
the upper and lower levels. If not, add oil to the upper
level.
2Upper level 
3Lower level
ÈFor models without reverse transmissions 
(RX10/RX10S/RX10M/RX10MS)
ÉFor models with reverse transmissions 
(RX10R/RX10RS/RXW10/RXW10S)
CAUTION:@ 
Make sure that no foreign material enters the drive
chain housing. 
@
4. Install the dipstick and align the notch 
4 of the dip-
stick handle with the projection 
5 of the drive chain
housing.
Chain tension...