Why Does My Chainsaw Keep Cutting Out? (Explained)
A chainsaw cutting out repeatedly can be frustrating and reduce productivity. However, there are several potential causes and solutions to this common problem. Getting to the root of the issue and taking preventive measures can help ensure smooth, uninterrupted chainsaw operation.
Common Causes
There are a few key reasons a chainsaw may cut out intermittently:
Fuel Delivery Issues
Fuel delivery issues are one of the most common causes of a chainsaw cutting out. Problems like a clogged fuel filter, contaminated fuel, issues with the carburetor, or a failing fuel pump can prevent proper fuel flow.
Ignition or Spark Plug Problems
Issues with ignition components like the spark plug, magneto, or electronic ignition module can prevent proper sparking, leading to cutting out.
Air Filter Clogged
A air filter clogged with dust and debris affects airflow to the carburetor, resulting in the engine cutting out.
Lubrication Problems
Low chain oil, bar oil holes clogged with sawdust, or an overly dry chain can cause overheating and intermittent cut outs.
Faulty Stop Switch
A stop switch that is sticking or malfunctioning can randomly cut power to the engine.
Step-By-Step Troubleshooting
Methodically testing different systems makes diagnosing the issue faster. Follow these steps:
Check Fuel
Start by checking fuel level and quality. Contaminated, old gas can cause performance issues.
Inspect Fuel Filter
Remove and check the fuel filter. Replace if clogged.
Check Spark Plug
Remove spark plug and test for spark by pulling the starter cord. No spark indicates ignition problems.
Inspect Air Filter
Check air filter to ensure it’s clean and not restricting airflow.
Check Chain Lubrication
Ensure bar oil holes aren’t clogged and oil tank has adequate lubricant.
Inspect Stop Switch
Ensure the stop switch moves freely and makes proper contact.
Assess Carburetor
If other areas check out, carburetor issues may be the culprit. Have serviced by a technician.
By methodically testing each system, you can isolate the issue and target the required repair.
Quick Fixes
Try these fast fixes first to get your chainsaw running again:
Clean Air Filter
Use compressed air or gentle brush to remove built-up debris.
Replace Fuel
Drain old gas and replace with fresh fuel mixture. Includes stabilizer additive.
Clean Spark Plug
Remove carbon build up on spark plug with wire brush. Re-gap if needed.
Clean Bar Oil Holes
Use wire to clear any obstructions in oil delivery holes.
Check Chain Tension & Lubrication
Ensure chain lubrication is adequate and chain tension is correct.
Check for Damaged Wiring
Inspect wires leading to stop switch, ignition module, and fuel delivery system.
These quick fixes only take a few minutes and can get your chainsaw running smoothly again.
Advanced Troubleshooting & Repairs
For continued issues, more in-depth troubleshooting and repairs may be needed:
Replace Fuel Filter & Lines
Clogged fuel filter or deteriorating fuel lines can restrict fuel flow.
Clean or Rebuild Carburetor
Carburetors can develop buildup and require ultrasonic cleaning or rebuild kit.
Replace Ignition Parts
Faulty ignition modules, magnetos, or spark plug connectors will require replacement.
Adjust Carburetor Settings
Improperly adjusted carburetor mixture screws or idle speed may need tuning.
Replace Fuel Pump Diaphragm
A ruptured fuel pump diaphragm prevents proper fuel delivery.
Check Flywheel Key & Recoil Spring
Sheared flywheel key or weakened recoil spring can cause start up issues.
For major repairs, it’s best to consult a trained technician to properly diagnose and service the chainsaw.
Preventative Maintenance
Performing regular maintenance helps avoid many cutting out issues:
Use Fuel Stabilizer
Prevent contaminated gas by always adding fuel stabilizer to the gas can.
Replace Air Filter
Inspect and replace air filter regularly to prevent restricted airflow.
Clean Spark Arrestor Screen
Ensure muffler spark arrestor screen is free of carbon buildup.
Sharpen Chain
Keep chain sharp to the proper specifications to prevent overheating.
Check Chain Tension
Ensure correct tension – tight but still able to pull round by hand.
Lubricate Bar Rails
Oil bar grooves to reduce friction from chain contact.
Clean Saw After Use
Use air compressor and brush to remove sawdust, sap, and debris.
Performing maintenance as recommended by the manufacturer will maximize performance and service life.
Common Questions
Why does my chainsaw cut out at full throttle?
If the chainsaw cuts out only under heavy load, it likely indicates a fuel delivery issue. Check the fuel filter, fuel lines, carburetor settings, and fuel tank vent.
Why does my chainsaw die when idling?
Cutting out only at idle is typically caused by improper carburetor adjustment. Turn both mixture screws clockwise gently until highest idle rpm is achieved.
Why does my chainsaw start but then stall?
If the chainsaw starts initially but dies shortly after, check the fuel filter and confirm adequate flow to the carburetor. May require filter replacement and carburetor cleaning.
Why does my chainsaw cut out when hot?
Overheating issues causing cut outs can stem from lubrication problems or too lean carburetor mixture. Check chain tension, bar groove oil flow, and carb settings.
Why does my chainsaw cut out after a few minutes?
A properly tuned chainsaw should run continuously without cutting out. If it dies after a short time, check the ignition components and fuel delivery parts like filter, lines and carburetor.
Why does my chainsaw die when tilting or upside down?
Fuel tank vents allow air flow to equalize pressure as fuel level changes. If vent is clogged, tilting the saw prevents proper fuel delivery causing stall out.
Conclusion
Chainsaws cutting out while operating creates safety hazards and reduces productivity. By methodically assessing fuel delivery, ignition, air intake, lubrication, wiring, and carburetion systems, the root cause can be isolated.
Performing regular maintenance and repairs as required will maximize runtime and minimize annoying mid-cut stall outs. Follow the helpful troubleshooting steps outlined to get your chainsaw running smoothly again.
