Teach you how to solve the six most common engine problems

More and more machinery and equipment are now using gasoline engines, including Honda, Kohler, Pepsi, Subaru and more. Gasoline engines are always subject to all types of problems, but today we will start with the common starting problems with gasoline engines.

In order for the engine to start smoothly, the following three conditions must be present.

1. Cylinders filled with an appropriately proportioned fuel-air mixture

2. Good pressure in the cylinder

3. At the best of times, Mars ignites the mix.

Without these three conditions, the engine will not start.

Gasoline engine in use in the process of common faults and troubleshooting methods

1.1. Oil spill: generally refers to oil leakage from the vent (waste oil pipe).

1.2. The gasoline is not clean, there are small impurities blocking the float needle valve. 

Measure: Clean the carburetor

1.3. The float is stuck, so the float needle valve can not work.

Action: Clean the carburetor

Suddenly turn off the engine in the process of using

1. There is no oil in the fuel tank or the oil circuit is not smooth.

Measures: Add gasoline, clean the carburetor.

2. The fuel tank cover is too tightly sealed, such as the fuel tank cover is sealed with plastic film.

Measure: Punch a small hole in the fuel tank cover.

3. The throttle return spring is broken.

Measures: Replace the throttle return spring.

4. The gasoline engine has serious heat, too little oil and not enough fuel, making the lubrication on the piston intermittent.

METHOD: Add some gasoline.

Difficulty in starting

Fuel System

(1) There is no gasoline in the fuel tank, or the fuel switch is off.

(2) The carburetor does not provide adequate air blockage, especially when cold.

(3) Gasoline is mixed with water, dust, or gum particles, which clogs the fuel line to the gasoline injector.

(4) Inferior gasoline and low quality gasoline do not vaporize sufficiently to make the proper proportion of fuel-air mixture.

(5) The carburetor needle valve is often open but not closed due to the clogging of oil sludge or rubber particles. When the engine is idling, fuel overflowing out of the carburetor can be determined to be due to this malfunction. In this case, this malfunction can be repaired by gently tapping the float chamber with the handle of a screwdriver or similar tool. If the malfunction cannot be eliminated, the float chamber will need to be disassembled to clean the carburetor needle valve dirt.

(6) If the carburetor produces a fuel overflow, or if excessive fuel flows into the cylinder when starting the engine, the fuel-air mixture is so thick that it will not burn. If this failure occurs, remove the spark plug and turn the starter pulley several turns by hand in order to allow this fuel-air mixture to evaporate into the air from the spark plug hole, leaving the carburetor damper open during this process, dry the spark plug and install it with the screw.

Compression System

If the difficulty in starting and power loss is not due to the fuel system or ignition system, check the following parts for lack of compression.

(1) The engine has been completely dry inside because it has been stored for a long time.

A loose or damaged spark plug will cause the gas mixture to leave the cylinder during the initial compression process due to this failure, producing a thundering noise.

(2) The cylinder head gasket seal has been damaged or the cylinder head has been loosened, causing the same hissing sound during the compression process.

(3) The valve clearance is not correct.

If standard compression is not obtained after following the above steps, remove the engine and further check the following items.

The valve will not close due to carbon or rubber particles on the valve stem.

If the piston ring is seized on the piston, remove the piston and connecting rod from the engine and sweep or replace the parts.

Long engine use and use in a dusty environment has caused the piston ring to exceed its service limit. Insufficient compression.

Ignition System

In the absence of spark, check the following.

(1) Is the ignition coil, spark plug, or contact breaker lead disconnected.

(2) Whether the ignition coil is damaged or shorted.

(3) Spark plug cable is wet or soaked in oil.

(4) Spark plug is dirty or wet.

(5) Spark plug electrode spacing is incorrect.

(6) Spark plug electrodes connected together or on.

(7) Spark plug electrodes incorrectly spaced.

Engine does not fire

(1) The spark plug electrode spacing is incorrect and should be adjusted between 0.6 and 0.7 mm.

(2) Spark cable is worn or leaking.

(3) Weak spark.

(4) Loose ignition wire connection.

(5) Water mixed with gasoline.

(6) Insufficient pressure.

(7) Carbon on spark plugs (used engine).

Engine stoppage

(1) The fuel tank is empty. Impurities such as water, dust, and rubber particles are mixed in the gasoline.

(2) Air resistance. For example, gasoline has evaporated because of the surrounding temperature.

Due to the use of volatile winter gas in the hot season, air resistance occurs in the fuel line or evaporator.

(3) Blocked vent holes in the fuel tank cover.

(4) Bearings are gummed up due to lack of lubrication.

(5) Permanent magneto engine or ignition coil failure.

Overheating of engine

(1) Crankcase oil level is too low, refuel immediately.

(2) Spark timing is incorrect.

(3) Low-quality gasoline used, or engine overloaded.

(4) Cooling air circulation blocked.

(5) Cylinder head cooling fins clogged with dirt.

(6) Engine is operating in an enclosed space without sufficient cooling air.

(7) Exhaust restriction or carbon buildup in combustion chamber.

(8) Engine using low-octane gasoline is deflagrating due to heavy load and low speed.

Engine knockout

(1) Poor quality gasoline.

(2) Engine operating under heavy load and low speed.

(3) Cylinder head carbon or lead build-up.

(4) Spark timing incorrect.

(5) Tie rod bearings loose due to wear.

(6) Piston pin slack due to wear.

(7) Engine overheated.

(8) Caused by engine overheating.

Engine backfires through carburetor

(1) Gasoline mixed with dust or water, or poor quality gasoline.

(2) Clogged suction valve.

(3) Valve overheated or red hot carbon particles in combustion chamber.

(4) Low engine body temperature.

Add the following for engine stalling after a few minutes of operation.

(1) Whether the fuel tank switch is open (should be fully open).

(2) The fuel tank lid is not ventilated, so that the negative pressure fuel in the tank does not flow down (whether there is a vent hole, or whether a plastic bag, film, etc. is used under the fuel tank lid to prevent the fuel from splashing out and blocking the vent hole).

(3) Dirt in the gasoline or fuel tank is blocking the high speed measuring hole of the carburetor (cleaning).

(4) Whether the fuel tank is too low, fuel can not flow to the carburetor (raise the fuel tank or handrail).

The above is a summary of the common failures of the smoothing engine, there are now two commonly used smoothing machines, one is power trowel, the other is ride on trowel. using mechanical smoothing, you can make the project completed more efficient and save manpower.