Yamaha Rx 1 User Guide

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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
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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 performance. Common problems are hard starting,
bogging, and plug fouling. Follow the Main Jet Setting
chart which is available at a Yamaha dealer carefully.
Proper carburetion adjustments will correct the air/fuel
ratio.
Remember: less air at higher altitude means there is
less horsepower available, even with proper carburetion.
Expect acceleration and top speed to be reduced at
higher altitudes.
To overcome operating with less power at high altitudes,
your snowmobile may also require different settings for
the drive chain gears and V-belt clutch to avoid poor per-
formance and rapid wear. If you plan to operate your
snowmobile at an altitude different from the area where
you bought it, be sure to consult a Yamaha dealer. They
can tell you if there are any changes necessary for the
altitude where you plan to ride.
CAUTION:@ 
The drive chain gears and V-belt clutch should be
adjusted when operating over a high altitude of
900 m (3,000 ft). Consult a Yamaha dealer. 
@
ESU00348
Adjusting the valve clearance
The valve clearance changes with use, resulting in
improper air-fuel mixture and/or engine noise. To prevent
this from occurring, the valve clearance must be adjusted
by a Yamaha dealer at the intervals specified in the peri-
odic maintenance chart.
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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 3,200 km
(2,000 mi) thereafter or at the start of a new sea-
son, otherwise the engine will wear quickly. 

The oil filter cartridge should be replaced every
20,000 km (12,000 mi) of operation. Have a
Yamaha dealer replace the oil filter cartridge. 
@ 
To change the engine oil (without oil filter cartridge
replacement)
1. Place the snowmobile on a level surface and apply
the parking brake. 
2. Remove the bottom panel 
1 and right side cover 
2. 
3. Start the engine, warm it up for several minutes, and
then turn it off. 
4. Place oil pans under both the engine and the oil tank
to collect the used oil. 
5. Remove the oil level gauge coupler 
3. 
6. Remove the oil level gauge/dipstick 
4 and the cylin-
der head cap 
5, and then remove the crankcase
engine oil drain bolt 
6 and the oil tank engine oil
drain bolt 
7 to drain the oil from the crankcase and
the oil tank.
NOTE:@ Dispose of used oil according to local regulations. @
7. Install the engine oil drain bolts, and then tighten
them to the specified torques.
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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 gauge/
dipstick. 

Make sure that no foreign material enters the
engine oil tank. 
@
11. Start the engine, and then let it idle for several min-
utes while checking it for oil leakage. If oil is leaking,
immediately turn the engine off and make sure the
engine oil drain bolts and oil level gauge/dipstick are
installed correctly. 
12. Turn the engine off, and then install the bottom cover
and right side cover.
CAUTION:@ 
If oil is leaking or the oil level warning indicator comes
on when the engine is running, immediately turn the
engine off and have a Yamaha dealer check the snow-
mobile. Continuing to operate the engine under such
conditions could cause severe engine damage. 
@
Tightening torques: 
Crankcase engine oil drain bolt: 
30 Nm (3.0 m·kgf, 22 ft·lb)
Oil tank engine oil drain bolt: 
16 Nm (1.6 m·kgf, 11 ft·lb)
Recommended engine oil: 
See page 6-2. 
Oil quantity: 
With oil filter cartridge replacement: 
3.0 L (2.6 Imp qt, 3.2 US qt) 
Without oil filter cartridge replacement: 
2.8 L (2.5 Imp qt, 3.0 US qt) 
Total amount: 
3.8 L (3.3 Imp qt, 4.0 US qt)
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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 counterclockwise
and remove it. 

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 dealer. 
@
CAUTION:@ 
Operating the engine with an improperly bled cool-
ing system can cause overheating and severe
engine damage. 
@
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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 antifreeze containing corro-
sion inhibitors. 
Coolant and water mixed ratio: 60:40 
Total amount: 4.7 L (4.14 Imp qt, 4.97 US qt)
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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, adjustment may be necessary.
To ensure proper clutch performance, the V-belt
position should be adjusted by adding a spacer on
each adjusting bolt when the V-belt position reaches
1.5 mm (0.06 in) below the edge. 
Have a Yamaha dealer make this adjustment. 
@CD-05E
NOTE:@ Apply the parking brake before replacing the V-belt.@
1. Remove the drive guard.
2. Rotate the secondary sliding sheave clockwise 
1
and push 
2 it so that it separates from the secondary
fixed sheave. 
New belt width 34.5 mm (1.36 in)
Belt wear limit width 32.5 mm (1.28 in)
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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 bolt.
Standard V-belt position 
a:
From 1.5 mm (0.06 in) above the edge of the second-
ary sheave to 0.5 mm (0.02 in) below the edge.
V-belt position Adjustment
More than 1.5 mm (0.06 in) 
above the edgeRemove spacer
From 1.5 mm (0.06 in) 
above the edge to 0.5 mm 
(0.02 in) below the edgeNot necessary 
(It is correct.)
More than 0.5 mm (0.02 in) 
below the edgeAdd spacer
Adjusting bolt tightening torque: 
10 Nm (1.0 m·kgf, 7.2 ft·lb) 
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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 hot after the engine has been run. Avoid
contact while they are still hot with any part of your
body or clothing during inspection or repair. 
@
1. Place the snowmobile on a level surface. 
2. Remove the dipstick 
1 and wipe it off with a clean
rag. Then put the dipstick in the hole.
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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 adjustment
1. Loosen the chain adjuster locknut. 
2. Turn the adjuster bolt clockwise until it is finger tight. 
3. Hold the adjuster bolt in place while tightening the
chain adjuster locknut.
1Chain adjuster locknut 
2Adjuster bolt
AB
Drive chain oil:API GL-3 
SAE 75 or 80
U8FA11.book  Page 18  Thursday, April 3, 2003  4:09 PM