The Chainsaw Starts Then Dies When You Give It Gas – Issue Resolved

the chainsaw starts then dies when you give it gas

As an avid chainsaw user, nothing grinds my gears more than when my trusty companion starts up with a roar, only to sputter and die as soon as I press the throttle. Many a tree remains half-felled in my backyard due to this vexing issue. But through trial, error, and scouring of forums, I’ve come to learn the main culprits behind the “start then die” phenomenon. Proper maintenance and timely troubleshooting can nip most problems in the bud before they leave you stumped in the middle of a job.

In this comprehensive guide, I’ll walk you through the likely reasons your chainsaw kicks the bucket when you give it gas. I’ll also provide tips to diagnose issues and actionable solutions to get your saw running right, so you can get back to felling trees and cutting logs without frustration. Chainsaws are complex power equipment, but with some DIY repair know-how, you can often resolve start-and-die issues yourself. So let’s rev up and dive into the main causes and fixes!

Common Causes of Chainsaw Starts Then Dies When You Give It Gas

After spending many a weekend puzzling over my balky chainsaw, I’ve isolated a few usual suspects behind the start-then-die syndrome:

Fuel Supply Issues

Like any internal combustion engine, chainsaws need a steady supply of fuel to run. Disruptions in the fuel delivery system are a major reason your chainsaw conks out when you hit the throttle. Common culprits include:

  • Gummy buildup of old fuel deposits restricting flow
  • Loose, cracked, or disconnected fuel lines
  • Clogged fuel filter choking off the fuel supply
  • Faulty fuel pump not delivering enough gas

So issues getting fuel to the engine could cause your chainsaw to die when revved up. Time to break out the toolbox and investigate!

Ignition Problems

No fuel, no fire. But the opposite is also true – no fire, no ability to combust fuel. Chainsaw ignition systems generate the high-voltage spark that ignites the air-fuel mixture in the cylinder. Problems here can also lead to start-then-die headaches. Watch for:

  • Fouled, cracked, or worn spark plug failing to spark
  • Defective ignition coil unable to generate adequate voltage
  • Blocked spark arrestor screen quenching the spark
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So if the spark isn’t sparking properly, your saw’s engine can cut out when revved.

The Chainsaw Starts Then Dies When You Give It Gas - Issue Resolved

Carburetor Issues

The carburetor mixes air and fuel in just the right proportions for optimal combustion. Adjustments to the carb’s inner screws regulate airflow and fuel supply. If these get thrown out of whack by vibrations or contamination, it can also induce the start-die issue by upsetting the engine’s delicate air-fuel balance.

Clogged Air and Fuel Filters

Small particles and debris can clog up the fuel and air filters, constricting the flow of gas and air into the engine. Just like kinking a hose, this fuel or air restriction causes the chainsaw engine to sputter and stall when revved.

Spark Plug Problems

The spark plug is key to igniting the fuel charge in the cylinder. An improperly gapped, fouled, or worn plug may work okay at idle, but fail to generate a consistent spark under higher loads. No spark, no boom.

Fuel Supply Issues

Let’s dive deeper into fuel supply problems and solutions. Nothing kills a project faster than a sputtering saw, so we’ve gotta keep gas flowing to that engine!

Stubborn Fuel Deposits

Over time, varnishes, gums, and oxidation within old gasoline can leave behind stubborn deposits within the fuel system – think of the sticky film left behind after spilled gas evaporates. This gumminess can partially block fuel ports, jets, lines and filters. With the fuel supply choked down, the engine may run fine at idle, but starve and stall once you hit the throttle.

To restore full fuel flow, you’ll need to dissolve and flush out those deposits. Start by draining old gas and running some fresh, high-octane fuel through the system. Consider using a fuel stabilizer at each fill-up to prevent new build-up. For heavy gum deposits, you may need to remove and soak carburetor parts in a little carb cleaner or acetone to fully dissolve away that gunk. A clean fuel system equals steady power.

Ignition Problems

No spark means no bang inside those combustion chambers. Let’s explore some ignition system issues that can lead to a chainsaw’s start-and-die syndrome.

Spark Arrestors and Fouled Spark Plugs

Spark arrestors prevent errant sparks from exiting the exhaust port by blocking and extinguishing them. But over time, they can get clogged with carbon deposits. This acts like a wet blanket, suppressing the spark. And fouled or failing spark plugs can provide too weak of a spark to ignite the fuel mixture once the engine is revved up.

Start by removing and cleaning the spark arrestor screen with some brake cleaner or carb cleaner spray. Check the spark plug next – look for cracked porcelain, excessive electrode erosion, or a frosted appearance indicating fuel fouling. Clean fouled plugs with a wire brush or replace if too far gone. For weakened sparks, install a fresh plug gapped to the manufacturer’s specs. That should get your ignition firing on all cylinders again!

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Carburetor Issues

The carburetor uses a pair of adjustable screws to fine-tune the air-fuel mixture. If these get improperly set, it can cause the chainsaw to stall when you hit the gas. Let’s learn how to tune them properly.

Adjusting the Carburetor Low-Speed (L) and Idle (I) Screws

The L and I screws meter the airflow and fuel supply at idle, low speeds, and transition periods. Back them out counterclockwise to enrich the mixture, or in clockwise to lean it out. Overtightening can cut off fuel flow entirely! Refer to your manual for proper turn-in specs. Often, about 1 & 1/2 turns out is a good starting point for both.

Turn the L screw clockwise gently until the saw starts sputtering, then back it out 1/8th turn until it runs smoothly. Repeat for the I screw. Adjust incrementally and take your time – rushing this can make things worse. Starting on the rich side then slowly leaning the mixture is safer. Set both screws for a reliable and high idle, with a quick response when you hit the throttle. A perfectly tuned carb means a chainsaw that roars through the cut!

Clogged Air and Fuel Filters

Small particles and debris floating around in the air and fuel can gunk up the filters over time. Let’s go over how to clean and maintain both so your engine can breathe easy.

Clearing Fuel and Air Filters

Fuel filters trap contaminants and water droplets in the gas before they reach your carburetor jets and delicate internals. The air filter stops dust and dirt from entering the combustion chamber. But if excessively dirty, both can restrict airflow and fuel flow.

Check the filters after every 5-10 hours of use. Tap a clogged fuel filter on a hard surface to dislodge particles. For the air filter, blow it clean with compressed air or gently brush it. Swap in new filters at least once per season or if they appear too grimy. Keeping the intake pathways clear is key for a smooth-running saw.

Spark Plug Issues

Spark plugs endure scorching temperatures and up to 10,000 explosive cycles per minute inside your chainsaw engine. Let’s explore maintenance tips to keep their spark consistently strong.

Spark Plug Gap and Carbon Fouling

Make sure your spark plug’s side electrode and center electrode are properly gapped according to your chainsaw manufacturer’s specifications. Too wide of a gap can result in a weak or intermittent spark when under heavy load. The spark may only jump the gap at low RPMs, causing the chainsaw to die when revved.

Also check for black, sooty carbon deposits on the plug’s firing end insulator which can form over time, shorting out the plug. Use a wire brush to gently clean carbon fouling, or replace the plug if excessively worn. Installing a fresh, properly gapped plug ensures reliable ignition performance and hours of uninterrupted cutting time.

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What Are the Common Causes for a Chainsaw to Bog Down When Given Gas?

When a chainsaw bogs down, it can be frustrating. Understanding the common causes for this issue can help prevent it from happening. A clogged air filter, a gummed-up carburetor, or a dull chain are often the culprits. Regular maintenance and cleaning, along with proper fuel mixture, can provide solutions to keep your chainsaw running smoothly. chainsaw bogs down: causes & solutions.

Frequently Asked Questions

Q1: How do I prevent my chainsaw from dying when I give it gas?

Regular maintenance and cleaning is key. Follow the manual’s guidelines for filter changes, spark plug replacement, fuel system cleaning, and air intake cleaning to prevent performance issues. Use fuel stabilizer and avoid old gas. Tune the carburetor and check ignition components seasonally. Address problems early before they strand you mid-job!

Q2: How often should I clean and maintain my chainsaw?

Inspect and clean the air filter every 5-10 hours of use. Swap in a fresh fuel filter every 50 hours or seasonally. Replace the spark plug yearly or after 100 hours of runtime. Fully clean the fuel system every few months – more often if issues arise. And give the saw a full tune-up at least once per cutting season.

Q3: What are the signs of a failing spark plug?

Look for corrosion, cracked porcelain, excessive electrode wear, or a grey/black color indicating fuel fouling. Hard starting, rough idling, lack of power under load, or starting then dying can all indicate spark plug problems. If in doubt, install a fresh plug.

Q4: How do I know if my chainsaw’s carburetor needs adjustment?

Symptoms like difficulty starting, stalling at idle, dying when revved, or fluctuating RPMs can suggest an improperly tuned carb. Try turning the L and I screws incrementally to find the optimum setting. If that doesn’t help, a full carb rebuild or replacement may be needed.

Q5: Can I use alternative oils for my chainsaw’s bar and chain?

It’s best to use the bar and chain oil specified for your model, usually SAE 30. Vegetable or bio-based oils lack adequate adhesion. Engine oil is too thin. Automatic transmission fluid can work in a pinch – but avoid any oils that could sling off the chain at high speeds.

Q6: How do I check if my chainsaw’s oil pump is working properly?

With the saw idling, touch the tip of the bar to a light-colored surface like cardboard. The oil droplets should leave visible streaks. With the chain brake engaged, you can also rev up the engine and watch for flung droplets. If oil output seems weak, the pump may need replacement.

Q7: What are some common issues with chainsaw oiling systems?

Clogged oil ports or lines, sticky oil from cold weather, depleted oil tanks, and failing oil pumps are prime suspects. Bar grooves loaded with sawdust can also block oil delivery. If the chain lacks lubrication, stop cutting immediately to prevent excessive wear and damage.


While chainsaw problems can be frustrating, arming yourself with some basic troubleshooting knowledge goes a long way. Tracing issues back to the fuel, air, ignition, or oiling systems helps isolate the root cause. With proactive maintenance and the solutions provided above, you can nip many common problems in the bud before they leave you in the lurch.

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