Opal fuel: trouble-shooting
The following list provides a variety of common problems and most probable causes. Whilst many problems are listed, not everything that can go wrong is covered. However, it can be a starting point for guiding you in the right direction.
Note: always seek advice from a qualified repairer.
Click on the relevant problem below to see a list of the possible causes
Problems
Engine will not start or is hard to start
Possible causes:
- fuel is stale and has carbonned the spark plug
- fuel tank is empty or shutoff valve is closed
- fuel line or fuel tank cap vent is clogged
- there is water in the fuel
- carburetor is over choked
- carburetor is improperly adjusted or needs service
- ignition system or its wiring is defective or ignition switch is off
- dead man or other cutoff switch is open or defective
- spark plug is fouled, improperly gapped, or damaged
Engine starts easily but dies after a few seconds
Possible causes:
Possible causes:
- fuel tank is empty or shutoff valve is closed
- fuel line or fuel tank cap vent is clogged
- carburetor is over choked
- carburetor is improperly adjusted or needs service
Engine idles roughly, unevenly, or surges
Possible causes:
- carburetor is dirty
- air leak in carburetor or intake manifold (e.g. bad O-ring, gasket or primer)
- carburetor is improperly adjusted or needs service
Engine misses under load
Possible causes:
- spark plug is fouled, improperly gapped, or damaged
- breaker points are pitted or improperly gapped, or condenser is bad
- carburetor needs adjustment or service
- fuel line, fuel filter, or fuel tank cap vent is clogged
- fuel shutoff valve partially closed
Engine knocks
Possible causes:
- carburetor is set too lean
- incorrect octane rating fuel used
- engine is overheating
- carbon buildup in combustion chamber
Engine lacks power, possibly after warm-up
Possible causes:
- old or stale Petrol
- spark plug is fouled, improperly gapped, or damaged
- very thick or dirty oil (4 Stroke)
- choke is partially closed
- carburetor needs adjustment or service
- air filter is clogged
- head gasket blown or damaged
Engine operates erratically, surges and runs unevenly
Possible causes:
- fuel line or fuel tank cap vent is clogged
- there is water in the fuel
- carburetor needs adjustment or service
- loose carburetor or intake pipe resulting in vacuum leak
Engine overheats
Possible causes:
- carburetor set too lean
- air intake or cooling fins are clogged
- excessive load
- insufficient or excessive oil
- improper oil viscosity (4 stroke) or mixture (2 stroke)
- excessive carbon buildup in combustion chamber
Crankcase breather passing oil
Possible causes:
- too much oil in crankcase
- engine speed is excessive
- oil fill cap or gasket is damaged or missing
- breather mechanism is dirty or defective
- piston ring gaps are aligned
- piston rings are worn
Engine backfires
Possible causes:
- carburetor set too rich
- spark plug has fouled and is firing intermittently
Summary
Always ensure your equipment is up to date with maintenance, use fresh fuel or 2 stroke fuel mixes. If in doubt consult your equipment manufacturer.