Engine Runs Poorly At High Rpm - Mercury 305 CID Service Manual

Engine Runs Poorly At High RPM

Also refer to "Poor Boat Performance"
Crankcase overfilled with oil
Anti-siphon valve (if equipped)
Plugged fuel tank vent
Fuel supply
Ignition timing
Low grade of fuel or water in the fuel
Spark plugs
Spark plug wires
Distributor cap or rotor
Coil
Distributor
Engine overheating
Low compression
Restricted exhaust
Index
1C-16 - TROUBLESHOOTING
Cause Special Information
Check oil level with boat at rest in the water.
Restricting fuel supply
Refer to "Carburetor Malfunctions"
(See "Table of Contents")
Fouled, burned, cracked porcelain, incorrect
heat range
Poor insulation, broken wires
Dirty or cracked
Excessive play in shaft
Refer to "Engine Overheats"
Worn valves, rings, cylinders, etc.
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