Check for spark at spark plugs then check fuel and fuel filter .
Troubleshooting a small Petrol engine that won't start
requires a series of short tests and the process of elimination.
Understanding the principles of how a small engine operates
is helpful but not necessary.
Proper disposal of hazardous liquids will be required.
The knowledge gained in the performance of this procedure
can be applied to many different types and sizes of internal combustion
The average weekend mechanic can complete the process in
about an hour.
Put on the safety glasses.
Remove the gas cap and check that there is gas in the fuel
Look at the inline gas cutoff valve located below the gas tank
on the fuel line and make sure it is in the on position, with the knob turned
straight in line with the fuel line.
Look at the spark plug and check that the wire is securely
plugged onto the plug.
Try to turn the spark plug by hand and make sure it is
screwed firmly into the hole.
Look at the ground strap by the spark plug and make sure it
is not touching the spark plug.
Look at the kill switch located by the controls and make
sure it is in the run position.
Remove the air filter by unsnapping its box-like cover or
removing the wing nut that holds it onto the carburetor.
Lift the air filter out of the holder and set it aside.
Spray a shot of starting fluid from the aerosol can into the
empty air filter area of the carburetor and try to start the engine.
Let the engine run about 30 seconds or until it dies.
Eliminate the electrical system as the cause of the
problem if the engine started right up, ran a few moments, and quit.
Remove the gas line from the carburetor by loosening its
hose clamp with the screwdriver kit.
Hold the fuel line over the clear glass container and let
some gas run into it.
Look at the gas, checking for water and impurities.
Drain the gas tank if the gas looked impure.
Remove the gas filter from the fuel line by loosening its
hose clamps with the screwdriver kit.
Replace the gas filter with a new one if the gas did not run
into the glass at a rapid pace.
Reinstall the gas line and gas filter.
Fill the gas tank with new gas.
Find a small drain bolt located on the very bottom middle
of the carburetor.
Place a small container that gas won't melt under it and
remove it with the wrench kit.
Let the old gas drain out of the bottom until the new gas
starts to flow out. Screw the drain bolt back into the bottom of the
Clean up any spilled gas off the motor and elsewhere with
the shop rag.
Place the rag in the metal bucket a safe distance from the
Clean the air filter with warm, soapy water if it is the
spongy type, or replace it with a new one.
Install the air filter. Start the engine.
Unplug the spark plug wire from the spark plug if the
engine did not start.
Hold the insulated part of the spark plug wire with one hand
and place the bare part about 1/4 inch away from the top of the spark plug.
Try to start the engine and watch for a spark between the
wire and the plug. Replace the spark plug wire with a new one if it shocked you
through the insulation.
Remove the spark plug using the spark plug wrench and
replace it with a new one if there was a spark.
Try to start the engine. Let the engine run until it
Do not do anything else if there was no spark, as the
trouble is inside the internal workings of the engine and requires professional
repair and tools.