Stihl MS 261 Starting (Step-by-Step)

To start an STIHL MS 261, set it on firm ground, engage the chain brake, and use the cold-start or warm-start position shown in your saw’s manual. Pull until it starts, then check that it idles safely and oils the chain. If it will not start, stop repeating pulls and check fuel, spark, and compression in order.

Thirty pulls with no result usually means it is time to change the test, not pull harder. Start with the correct procedure and a safe setup. If the saw still will not run, a few simple checks can help separate a flooded engine from a fuel, spark, or compression problem, before you buy parts.

The MS 261 has a 50.2 cm³ two-stroke engine. Controls and features can differ by model year and market, so use the manual for your exact saw. The steps below follow the usual STIHL starting process while flagging where your manual takes priority.

Equipment Setup and Safety Preparation

This section covers the checks to make before you pull the starter. A saw that is set up safely is easier to start and less likely to move unexpectedly. Check the chain, brake, controls, fuel, and work area first. If any safety part is damaged or does not work, do not start the saw.

1. Wear protective gear. Use a helmet with eye and face protection, hearing protection, chainsaw-rated leg protection, gloves, and boots with good traction.
2. Check the work area. Set the saw on firm, level ground. Keep people clear, check your footing and escape route, and look for overhead hazards. If work is near power lines, contact the utility and follow required clearance rules.
3. Inspect the saw. Check that the chain is correctly tensioned, the chain brake works, and the throttle lockout, chain catcher, handles, bar, and chain are sound. Do not start a saw with a damaged control or loose part.
4. Check fuel. Use fresh fuel mixed with STIHL two-stroke engine oil at 50:1, following the fuel specification in the manual for your saw. Never use straight gasoline or the wrong mix. An incorrect mix can quickly damage the engine.
5. Check the cutting setup. Use only a bar, chain, and sprocket combination approved for your exact saw. Many MS 261 setups use a .325-inch chain pitch, but that is not universal. Confirm the pitch, gauge, and drive-link count on the bar and in the approved parts information. Matching bar length alone is not enough.

Takeaway: If the saw passes the safety check and has fresh, correctly mixed fuel, move to the start procedure. If not, correct the setup first.

Field Cutting and Landscaping Operation

This section explains how to start a cold or warm MS 261 and what to check before cutting. “Cold start” means the engine has cooled and needs the cold-start setting. “Warm start” means it has been running recently. Use the control positions shown in your manual, since the procedure can vary with the saw’s version.

Cold-start procedure

1. Put the saw on firm ground. Keep the bar and chain clear of the ground and other objects.
2. Engage the chain brake.
3. Set the master control to the cold-start or choke position shown in your manual. If your saw has a decompression valve, press it as directed.
4. Hold the saw steady using the method in the manual. Keep your hand away from the chain and do not drop-start the saw.
5. Pull the starter until the engine fires briefly. This first cough is a sign to change the control setting, not to keep pulling with full choke.
6. Move the control to the prescribed starting-throttle or warm-start position, then pull until the engine starts. Do not use the throttle to hold the engine at high speed.
7. If the engine starts but stops, follow the manual’s restart setting. Once it runs, briefly squeeze and release the throttle as directed so the control can return to idle.

Warm-start procedure

With a warm engine, use the warm-start setting in the manual, normally without full choke. Keep the brake engaged while starting. Once the saw is running, check that it idles without the chain moving. Release the brake only when you are ready to cut.

Before cutting, confirm that the chain stops at idle and that bar oil reaches the chain. Use proper chain-and-bar oil. Oil flow and engine speed details vary across MS 261 versions, so use the exact manual rather than a general figure.

Keep a firm two-handed grip and secure footing. The bar nose’s upper quadrant can cause rotational kickback if it contacts wood or another object, driving the bar up and back toward you. Keep the nose clear, do not cut above shoulder height, and assess wood tension and pinch hazards before each cut.

Takeaway: A successful start is not the only check. Verify safe idle and oil delivery before cutting.

Maintenance, Sharpening, and Tuning

This section covers what to check when correct starting steps do not work. A flooded engine, poor fuel delivery, weak spark, and low compression can look similar at first. Change one thing at a time, and stop if a check requires tools or skills you do not have.

Start with the simple, low-risk checks:

• Confirm the control setting. A cold engine needs the cold-start procedure; a warm engine normally does not need full choke.
• Check for flooding. A strong fuel smell or a wet spark plug can point to excess fuel. Do not keep pulling with the choke set. Follow the manual’s flooded-engine procedure for your saw; control positions differ.
• Check fuel age and mix. If the fuel is stale, contaminated, or mixed incorrectly, do not keep trying to start the saw. Drain and handle it as directed by the manual and local rules, then use fresh fuel at 50:1.
• Inspect the air filter. A heavily blocked filter can affect engine operation. Clean or replace it as the manual directs, and refit it correctly.
• Inspect the spark plug. Remove it only after the saw is off and cool, following the manual. A wet plug may indicate flooding; a damaged or badly fouled plug needs attention. Use the specified plug type and gap.

If these checks do not solve the problem, test the ignition and fuel systems rather than guessing at parts. An inline spark tester can show whether the ignition produces a spark during cranking. Keep fuel away from ignition sources, and do not test for spark beside spilled fuel or an open fuel container. No spark can involve the plug, lead, switch, or ignition module; it does not prove which part has failed.

A fuel-system fault may involve a blocked filter, line, tank vent, or carburetor. These parts require specific checks, and replacing the carburetor without testing can waste money. Compression is checked with a suitable gauge and the method in the service information. There is no single compression threshold that applies to every MS 261 version and test method. If compression seems low, or you hear unusual internal noise, stop and seek qualified service.

I use a simple rule when diagnosing a no-start: first verify what the saw is doing, then test the system that could explain it. For example, a wet plug after repeated full-choke pulls points toward flooding, but it does not rule out other faults. A dry plug after correct cranking can point toward a fuel-delivery problem, but it is not a diagnosis by itself.

Illustrative troubleshooting cases

• The saw coughs once, then will not run. The next step is to move from the cold-start position to the manual’s starting-throttle position. Repeating full-choke pulls can flood the engine.
• The saw has fresh fuel but will not fire, and the plug is dry. Check the start procedure, fuel condition, and filter before buying a carburetor. If the problem remains, fuel-system testing is needed.
• The saw starts but the chain moves while idling. Shut it off. Do not try to solve this by cutting; the saw needs an idle or clutch-system check.

For sharpening, set chain depth gauges to the chain maker’s specification. 0.025 inch (0.65 mm) is common for many STIHL chains, but confirm the exact chain type before filing. A dull chain should be sharpened, not forced through wood. Use the correct bar-and-chain combination and never defeat the chain brake.

Takeaway: Use symptoms to choose the next test, not to name a replacement part. Stop and get service if safe diagnosis requires specialized equipment.

Storage and Seasonal Care

This section explains how to leave the saw ready for its next start. Safe shutdown, cleaning, and storage help prevent avoidable starting trouble. Follow your MS 261 manual for fuel storage and long-term storage, since the correct steps can depend on the fuel used and the time stored.

To shut down, set the control to stop and wait for the chain to stop fully. Let the saw cool before refueling or servicing it. Refuel away from flames, sparks, and other ignition sources.

After use, clean the sprocket cover, bar groove, oil ports, and air-intake area. Check chain condition and tension, and remove packed debris. Keep the chain sharp and properly oiled; do not run the saw with a dry chain.

For longer storage, follow the manual’s instructions for fuel and the saw’s storage position. Do not guess at fuel stabilizer use or storage steps. Before the next start, inspect the saw again and use fresh, correctly mixed fuel if required by the manual.

Takeaway: A clean saw and correct storage routine make the next cold start more predictable. Always repeat the safety check before starting.

Common Questions About Starting an MS 261

How do I start a cold STIHL MS 261?

Set the saw on firm ground, engage the chain brake, and select the cold-start position shown in your manual. Pull until the engine fires, move the control to the prescribed starting-throttle position, then pull until it starts.

Should I use full choke for a warm start?

Usually not. A warm engine normally uses the warm-start setting, not full choke. Check your manual for the exact control position.

Why does my MS 261 start, then die?

It may need the next step in the starting sequence, or it may have a fuel, air, or ignition issue. Follow the manual’s restart setting, then check fuel condition and the air filter if it still will not run.

What should I do if the spark plug is wet?

A wet plug can indicate that the engine is flooded. Stop using full choke and follow the manual’s flooded-engine procedure. Do not test for spark near fuel or fuel vapors.

What fuel mix does the MS 261 use?

Use unleaded gasoline and STIHL two-stroke engine oil at 50:1, with fresh fuel that meets the specification in the applicable manual. Do not use straight gasoline or the wrong ratio.

Is every MS 261 chain .325-inch pitch?

No. A .325-inch pitch is common, but configurations vary. Match the chain pitch, gauge, and drive-link count to the bar markings and the approved equipment for your saw.

Why does the chain move when the saw is idling?

The chain should stop at idle. Shut the saw off and have the idle or clutch system checked before using it again.

How can I tell if the saw is getting bar oil?

Use the oil-delivery check described in your manual. If the chain appears dry or oil delivery is uncertain, stop and inspect the oil level, bar groove, and oil ports before cutting.

When should I stop troubleshooting at home?

Stop if the saw has damaged safety parts, no spark after basic checks, suspected low compression, unusual internal noise, or a fault that needs service equipment. Testing first is safer and cheaper than replacing parts at random.

(This article was written by one of our staff writers, Robert Callahan. Visit our Meet the Team page.)