Tuesday, August 22, 2023

Chainsaw Ignition System

 The chainsaw ignition system is responsible for generating the high-voltage spark that ignites the fuel-air mixture in the engine's combustion chamber. This spark initiates the combustion process, driving the piston and creating the power necessary for the engine to operate. The ignition system plays a crucial role in the overall performance and starting of the chainsaw. Here's a general overview of how the ignition system of a chainsaw works:

ignition coil from a chainsaw ignition system

Ignition Coil:
The ignition coil is a primary component of the ignition system. It consists of two coils of wire, the primary coil and the secondary coil, wrapped around an iron core. The primary coil is connected to the engine's power source (usually the magneto or flywheel) and is responsible for storing and amplifying electrical energy.

chainsaw ignition system flywheel

The flywheel is a rotating component attached to the crankshaft of the engine. It contains a permanent magnet or magnets that generate a magnetic field as the flywheel spins. This changing magnetic field induces a voltage in the primary coil of the ignition coil.

Trigger Mechanism: The trigger mechanism, often referred to as the "points" or "contact breaker," controls the timing of the ignition spark. In older chainsaw models, the trigger mechanism consists of a set of mechanical contacts that open and close as the flywheel rotates. In modern chainsaws, electronic ignition systems (CDI - Capacitor Discharge Ignition or digital systems) have largely replaced mechanical points.

Condenser/Capacitor (Optional): In older ignition systems, a condenser (also known as a capacitor) is used to suppress arcing and prolong the life of the points. It stores excess energy from the primary coil and releases it when the points open, aiding in spark generation.

spark plug from a chainsaw ignition system

Spark Plug:
The spark plug is connected to the secondary coil of the ignition coil. When the ignition system is activated, the high voltage generated in the secondary coil is sent to the spark plug. The spark plug's electrode gap creates a spark that ignites the compressed fuel-air mixture in the engine's combustion chamber.

spark plug wire from a chainsaw ignition system

Spark Plug Wire:
The spark plug wire connects the ignition coil to the spark plug. It carries the high voltage from the coil to the spark plug.

Kill Switch: The chainsaw is equipped with a kill switch, also known as an on/off switch, that allows the operator to stop the engine by interrupting the flow of electricity to the ignition system. This is an important safety feature.

Operation of the Ignition System In Chainsaws 

The operation of a chainsaw ignition system involves the following steps:

As the flywheel rotates, it generates a changing magnetic field that induces a current in the primary coil of the ignition coil.

The primary coil stores and amplifies this current.

The trigger mechanism (points or electronic component) determines the timing of the spark by controlling when the primary circuit is interrupted.

When the primary circuit is interrupted, the stored energy in the primary coil is rapidly released to the secondary coil.

The secondary coil amplifies the voltage even further, sending a high-voltage pulse to the spark plug.

The spark plug generates a spark across its electrodes, igniting the fuel-air mixture in the engine's combustion chamber.

Obviously, the chainsaw ignition system is a critical system of a chainsaw's operation, ensuring reliable starting, smooth operation, and efficient power delivery.

At HLSproParts.com you will find all kinds of chainsaw ignition system parts at great prices

Thursday, August 17, 2023

What Do Small Engine Mechanics Need To Know About Electronics?

 Small engine mechanics involve a variety of electronics, especially in modern engines. These electronics play a crucial role in engine performance, diagnostics, and overall functionality. Some of the electronics involved in small engine mechanics include:

Ignition System: Modern small engines often use electronic ignition systems, which include components like ignition coils, spark plugs, and electronic control modules (ECMs). These systems generate and control the spark that ignites the fuel-air mixture in the engine's combustion chamber.

Fuel Injection Systems: Electronic fuel injection (EFI) systems have become common in small engines. EFI systems use sensors to measure factors such as engine temperature, air intake, and throttle position to optimize fuel delivery for better efficiency and performance.

Engine Control Module (ECM): The ECM, sometimes referred to as the Engine Control Unit (ECU), is the brain of the engine. It processes sensor data and controls various engine functions, including fuel injection, ignition timing, emissions, and more.

Sensors: Small engines incorporate various sensors to monitor engine conditions and provide data to the ECM. These sensors can include oxygen sensors (O2 sensors), temperature sensors, throttle position sensors, crankshaft position sensors, and more.

Digital Displays: Some small engines feature digital displays that provide information to the operator, such as engine RPM, temperature, oil pressure, and warning indicators.

Diagnostics: Mechanics use specialized diagnostic tools, such as scan tools and code readers, to interface with the engine's electronics. These tools can read error codes, perform diagnostic tests, and help identify issues within the engine's electronic systems.

Electric Start Systems: Many small engines, especially those in lawn mowers, generators, and recreational vehicles, use electric start systems that rely on batteries and solenoids to engage the starter motor.

Safety Systems: Some small engines incorporate safety features controlled by electronics, such as low-oil shutdown systems that prevent engine damage when oil levels are too low.

Charging Systems: Small engines with electrical components (lights, electronics, etc.) often include charging systems that replenish the battery while the engine is running. These systems may include alternators or stators.

Emissions Control Systems: Electronic components play a vital role in emissions control, including catalytic converters and oxygen sensors, which help ensure compliance with environmental regulations.

It's mandatory for small engine mechanics to have a good understanding of these electronic systems to diagnose and repair issues effectively. As technology continues to advance, electronics will likely play an even more significant role in the operation and maintenance of small engines. 

Of course, not all of these electronic components are found in every machine. So...

What are all of the electrical components of a chainsaw?

A chainsaw, like many small engines, incorporates various electrical components to enhance its functionality, safety, and user experience. While the exact components can vary between different models and manufacturers, here's a general overview of the common electrical components found in a chainsaw, and a basic overview of what they do:

Chainsaw Ignition System

Ignition Coil: Generates high-voltage electricity to create the spark needed for combustion.

Spark Plug: Ignites the fuel-air mixture in the engine's cylinder.

Chainsaw Starter System:

Starter Motor: Engages the engine's crankshaft to start the engine.

Starter Solenoid: Controls the flow of electrical current to the starter motor.

Recoil Starter: Manual pull-start mechanism for starting the engine.

Chainsaw Switches and Controls:

On/Off Switch: Controls the power supply to the ignition system.

Throttle Trigger: Controls the engine's speed and RPM.

Choke Control: Adjusts the air-fuel mixture during engine startup.

Safety Interlock Switches: Ensure that the chainsaw operates safely, such as a chain brake engagement sensor.

Chainsaw Safety Features:

Chain Brake Sensor: Detects sudden movements or kickbacks and activates the chain brake to stop the chain's rotation.

Inertia Sensor: Detects abrupt movement and can trigger the chain brake.

Chainsaw Electronic Control Module (ECM):

Engine Control Unit (ECU): Monitors and controls various engine functions, including ignition timing and fuel injection.

Chainsaw Fuel System Components:

*Fuel Pump: Transfers fuel from the tank to the carburetor or fuel injection system.

Fuel Solenoid: Controls fuel flow in EFI systems.

Fuel Level Sensor: Measures fuel level and sends information to the ECM.

Chainsaw Bar and Chain Oil System:

*Oil Pump: Supplies lubricating oil to the bar and chain for smoother cutting.

Oil Flow Control: Adjusts the rate of oil delivery to the bar and chain.

Chainsaw Charging System (if applicable):

Alternator or Stator: Generates electricity to charge the battery and power electrical components.

Indicator Lights and Displays (in some models):

Oil Level Indicator: Warns when the bar and chain oil level is low.

Overheating Indicator: Alerts the operator if the engine is overheating.

Chainsaw Magneto (optional):

Generates electricity through the engine's rotation to power ignition and other electrical systems.

It's important to note that not all chainsaws will have every one of these components, and the specific configuration can vary based on the chainsaw's design and intended use. As technology advances, more advanced features and electronics may be integrated into chainsaws to improve performance, efficiency, and safety.

*Most chainsaw pumps do not use electricity to operate. Instead, they are typically powered by the engine's mechanical motion. 

Thursday, August 3, 2023

Chainsaw Fuel Related Problems Common to All Outdoor Power Equipment

Chainsaws and lawn mowers, like any other small engines in outdoor power equipment, can experience various fuel-related problems that affect starting and running performance. Here are some common issues related to chainsaw fuel systems and their potential causes:

How Fuel Affects Chainsaw Starting When Chainsaw Won't Start

Stale Fuel: If the mower has been sitting with fuel in the tank for an extended period, the fuel can become stale and less effective. Stale fuel doesn't burn well, making it difficult for the engine to start.

Clogged Fuel Filter: A clogged fuel filter can prevent fuel from reaching the carburetor, leading to starting issues.

Dirty Carburetor: Dirt or debris in the carburetor can block the fuel passages and jets, affecting the fuel-air mixture and making the engine hard to start. So can old fuel, as it gets gummy and messes up carburetors and fuel lines.

How Fuel Can Cause Engine Stalling or Running Rough

An engine can stall or run rough when it's not getting enough, or proper mixture of, combustible ingredients.

Water in Fuel: Moisture can enter the fuel tank, causing the engine to stall or run rough. This could be due to leaving the mower in a rainy environment or using a fuel container that has water in it.

Clogged Air Filter: A dirty air filter can disrupt the air-to-fuel ratio, leading to rough running or stalling.

Carburetor Issues: A faulty or misadjusted carburetor can cause poor fuel delivery, leading to rough engine operation.

Choke: If the engine is choked when it should not be, or choked too much it'll run badly and eventually stall. The fuel to air mixture cannot be too rich or too lean for smooth running engines. An engine needs less air to start, or as it warms up, so the choke needs to be closed to choke off the air supply somewhat. Then when the engine is warm, the choke must be fully open to allow ample air to mix with the fuel.

Fuel Problems Can Cause Excessive Exhaust Smoke

Over-Choked Engine: If the engine is over-choked, it can cause excessive fuel to enter the combustion chamber, leading to black smoke in the exhaust.

Oil in the Fuel: Accidentally adding oil to the fuel tank instead of the oil reservoir can cause blue or white smoke in the exhaust.

Fuel Leaks Are Common Fuel Related Problems in Chainsaws and Mowers

Damaged Fuel Lines or Fittings: Cracked or damaged fuel lines or fittings can cause fuel leaks, which are not only wasteful but also hazardous.

Can Fuel Cause Lack of Power?


Dirty Fuel System: A dirty fuel system, including the fuel tank, fuel lines, and carburetor, can restrict fuel flow, resulting in reduced engine performance.

Improper Fuel Mixture: Using the wrong fuel-to-oil ratio (in 2-stroke engines) can affect engine power and cause damage.

How To Troubleshoot Chainsaw Fuel System Problems

To troubleshoot and fix any of the above issues, follow these steps:

Always use fresh, clean fuel. If yours has been sitting for some extended amount of time, then dump it and get fresh gas from the pumps. Also, if you suspect water in the fuel, drain the tank and refill with fresh fuel.

Check the fuel lines and fittings for any signs of damage or leaks. The problem could be that the gas is not getting to the destination, or not in sufficient quantity or speed. 

Replace the fuel filter regularly as recommended by the manufacturer. Clogs are a major cause of fuel flow problems and they're often caused by a dirty filter. 

Engines have to breathe too! Ensure the carburetor is clean and properly adjusted so it can manage the proper air to fuel mixture. Also, clean or replace the air filter as needed.

Mower and Chainsaw Repair

If you're unsure about handling the repairs yourself, it's best to take outdoor power tools to a qualified technician or a service center for inspection and maintenance.

Mower and Chainsaw Parts