Snowmobile Polaris 550 IQ Shift / 550 IQ 136 / 550 IQ LXT (2013 year). Manual - part 17

70

MAINTENANCE

Spark Plugs

It’s very important to use the correct spark plug for your machine. A 
spark plug with a heat range too high will cause engine damage. A spark 
plug with a heat range too low will cause excessive fouling and engine 
malfunctioning. Change the spark plugs every 2000-2500 miles (3200-
4000 km).

NOTICE: A spark plug with a heat range too high will always cause engine dam-

age if the engine is operated in conditions more severe than intended 
for that plug. Always use the spark plugs recommended for your 
snowmobile. See the specifications section beginning on page 98.

A new engine can cause temporary spark plug fouling due to the preser-
vative added during the assembly process. Avoid prolonged idle speeds, 
which cause plug fouling and carbonization.
• Use recommended spark plugs with the proper gap.
• Use only resistor-type spark plugs.
• Torque spark plugs to 18-22 ft. lbs. (24-30 Nm).
• Always carry spare spark plugs.

Spark plug condition is indicative of engine operation. The spark plug 
firing end condition should be read after the engine has been warmed up 
and the vehicle has been driven at higher speeds. Immediately check the 
spark plug for correct color.

CAUTION! A hot exhaust system and engine can cause burns. Wear 
protective gloves when removing a spark plug for inspection.

Tip: Incorrect fuel mixture can often cause a spark plug to appear too dark or too 

light in color. Before changing spark plug heat ranges, be sure the correct 
main jet is installed in the carburetor(s). Refer to the Owner's Manual Sup-
plement or see your dealer.

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MAINTENANCE

Spark Plugs

Spark Plug Condition

Normal Plug

The normal insulator tip is gray, tan or light brown.  There will be few 
combustion deposits.  The electrodes are not burned or eroded.  This 
indicates the proper type and heat range for the engine and the service.

The tip should not be white.  A white insulator tip indicates overheating, 
caused by use of an improper spark plug or incorrect carburetor/throttle 
body adjustments.

Wet Fouled Plug

The wet fouled insulator tip is black. A damp oil film covers the firing 
end. There may be a carbon layer over the entire nose. Generally, the 
electrodes are not worn. General causes of fouling are excessive oil, use 
of non-recommended injection oil, improper use of the choke, or incor-
rect carburetion adjustments.

Spark Plug Removal and Replacement

1. Remove the spark plug cap.

2. Rotate the spark plug counter-clockwise to remove it.

3. Reverse the procedure for spark plug installation. 

4. Torque to 18-22 ft. lbs. (24-30 Nm).

5. Reinstall the spark plug cap.

72

MAINTENANCE

Intake Filters

The intake foam filters limit snow 
ingestion into the intake system. 
When operating in loose powder 
snow, check the foam filters period-
ically to remove any accumulation 
of snow.

NOTICE: Operating the snowmobile 

with the intake filters removed 
may cause carburetor icing. 
The result will be poor fuel 
economy or carburetor mal-
function. Always reinstall the 
intake filters before operating 
the snowmobile.

Oil Lines

Inspect oil line condition every 1000 miles (1600 km).

Oil Filter

The oil filter is located at the side of 
the oil tank. Have your dealer change 
the oil filter and bleed the system 
annually or every 1000 miles (1600 
km). 

Tip: The direction of the arrows indicates 

the direction of flow through the fil-
ter.

Fuel Pump

All fuel pump service must be performed by an authorized POLARIS 
dealer. Do not attempt to service the fuel pump.

X

73

MAINTENANCE

Fuel Filter/Fuel Lines

See your POLARIS dealer for replacement of the under-tank fuel filter 
every 1000 miles (or annually).

Inspect the fuel lines regularly for signs of deterioration or damage. 
Always check fuel line condition after periods of storage. Normal dete-
rioration from weather and fuel compounds may occur. Replace worn or 
damaged fuel lines promptly.

NOTICE: Kinking the fuel lines or using a pliers or similar tools to remove fuel 

lines may cause damage to the lines. If a fuel line has been damaged 
or kinked, replace it promptly.

Cooling System

Inspect the fan intake and outlet edge seal at the input and output for 
cracks, loosening of duct and blockage or obstructions. Make any neces-
sary repairs promptly.

Exhaust System

Check the exhaust system for wear or damage at approximately 2000 
miles (3200 km). Always allow the engine and exhaust system to cool 
completely before inspecting.

CAUTION! Hot exhaust system parts can cause burns. Allow adequate time for 
the exhaust system to cool. Never perform this procedure with the engine 
running.

1. Open the hood and inspect the muffler and pipes for cracks or dam-

age.

2. Check for weak or missing retaining springs or damper/support 

grommets.

3. Check for loose clamps on the pipe covers.