Engine Troubleshooting - Polaris 2003 Pro X Service Manual

ENGINE
Troubleshooting
PROBLEM
Will not start/ -Check ignition switch for run position, moisture contamination
hard starting -Check auxiliary shut-off switch operation
-Check fuel supply
-Check wiring from engine to coil(s) or spark plug(s)
-Check spark plug(s)
-Disconnect engine connector to eliminate any shorts that might be in the system
-If starter won't work (electric models), check wires from starter solenoid and battery or check battery
and battery cables
-Open or broken reed valves
Low compres- -Crankcase plug is out
sion -Head gasket faulty
-Poor ring sealing, piston damage
No spark -Spark plug fouled
-Secondary coil bad or wires disconnected
-Primary coil shorted or open
-Ignition switch shorted, contaminated with moisture
-Auxiliary switch shorted or contaminated with moisture
Engine idles but -Restricted fuel flow/air flow
no acceleration -Clogged main jet
-Timing
-Clutching
Engine runs but -Clogged fuel filter
fails to reach -Incorrect track tension
maximum RPM -Incorrect main jet
-Throttle slides not fully open
-Chain too tight
-Clutching
-Excessive driveline friction (Hi-Fax overheating)
Engine runs but -Incorrect air mixture setting
fails to idle -Throttle stop screw incorrectly adjusted
-Dirt in pilot jet
-Low compression
-Tight belt
-Piston damage
-Chokes not seating
Engine runs, -Chokes are not seating
but overloads -Fuel pump diaphragm is ruptured (caused by engine backfiring)
with fuel -Carburetor slides are not synchronized
-Too large main jet
-Needle and seat not seating properly
-Incorrect float level
-Check reed valve condition
Carburetion and -If a lot of riding is on trails, and plugs foul and get black when doing so, verify all tune up adjustments:
plug fouling carb sync, oil pump adjustment, pilot screw setting, spark plug type and gap, venting for carbs, proper
jetting for altitude and temperature, belt tension, clutch operation. If tune up items are correct, check:
float level, jet needle position, jet needle wear, inlet needle and seat wear, etc.
Engine runs but -Coolant level
overheats -Incorrect main jet
-Incorrect timing
-Incorrect spark plug
-Water pump belt loose or broken
-Cooling restriction
-Air in cooling system
-Inadequate snow for cooling (ice and/or marginal conditions)
2.64
PROBABLE CAUSE