How To Start A Stihl MS250 Chainsaw: Easy Guide

How To Start A Stihl Ms250 Chain Saw
Image Source: i.ytimg.com

How To Start A Stihl MS250 Chainsaw: Easy Guide

Can you easily start a Stihl MS250 chainsaw? Yes, with the right steps and a little practice, starting your Stihl MS250 chainsaw is straightforward. This guide will walk you through everything you need to know for a successful first start and ongoing operation, including essential Stihl MS250 setup, Stihl MS250 assembly, and Stihl MS250 safety.

The Stihl MS250 is a popular choice for homeowners and professionals alike, known for its reliability and power. Getting it ready to go and starting it correctly ensures it performs at its best and lasts for years to come. We’ll cover everything from preparing your saw to troubleshooting common issues.

Getting Your Stihl MS250 Ready for Action

Before you even think about pulling the starter cord, proper Stihl MS250 setup and Stihl MS250 assembly are crucial. This ensures your chainsaw is safe and ready for use.

Unboxing and Initial Inspection

When your Stihl MS250 arrives, it will likely come in a box. Carefully open the packaging and remove all components.

Chainsaw Body: The main unit.
Guide Bar: The long metal piece the chain runs on.
Saw Chain: The cutting chain with teeth.
Chain Brake Handle: A safety feature.
Tool Kit: Usually includes a spark plug wrench and screwdrivers.
Owner’s Manual: Do not skip this! It contains vital, model-specific information.

Lay out all the parts and check for any damage that may have occurred during shipping. If anything looks amiss, contact your retailer immediately.

Assembling the Guide Bar and Chain

This is a key part of your Stihl MS250 assembly.

Attaching the Guide Bar

Locate the Bar Nuts: On the side of the chainsaw where the bar mounts, you’ll find two nuts. Loosen these nuts using the provided tool, but do not remove them completely.
Remove the Sprocket Cover: Pull out the mounting studs that were previously under the nuts. Then, slide off the sprocket cover.
Position the Guide Bar: Slide the guide bar onto the mounting studs. Ensure the drive links of the guide bar groove match up with the clutch sprocket. The nose of the guide bar should point upwards and away from the saw.
Fit the Saw Chain: Loop the saw chain around the guide bar, starting at the nose and working your way down. The cutters on the chain should be facing forward, towards the nose of the bar, on the top side of the bar.
Engage the Chain Tensioner: Most Stihl saws, including the MS250, have a manual chain tensioning system. Locate the tensioning screw, usually found on the underside of the guide bar near the motor. Turn the screw clockwise to take up slack in the chain. You’ll want the chain to be snug but still able to move freely around the bar by hand.

Setting the Correct Chain Tension

Proper Stihl MS250 chain tension is critical for both performance and safety.

Too Loose: The chain can fly off the bar, which is extremely dangerous.
Too Tight: This puts excessive strain on the engine, clutch, and bar, leading to premature wear and poor cutting.

How to Check and Adjust:

Ensure the engine is off and the chain brake is engaged.
Gently pull the chain downwards from the underside of the guide bar. It should lift slightly but immediately snap back into place, and the links should remain seated in the bar groove.
If the chain is too loose, tighten the tensioning screw (usually a small knob on the side or front of the saw) clockwise.
If the chain is too tight, loosen the tensioning screw counter-clockwise.
Re-check the tension after a few minutes of use, as new chains can stretch.

Securing the Sprocket Cover

Place the sprocket cover back over the guide bar and chain.
Align the holes in the cover with the mounting studs.
Thread the bar nuts back onto the studs and tighten them by hand.
Using your tool, tighten the bar nuts securely. Once again, ensure the chain can still be moved manually.

Fueling Your Chainsaw: The Right Mix

Using the correct Stihl MS250 fuel mixture is non-negotiable for engine longevity and performance. Stihl 2-stroke engines require a specific blend of gasoline and 2-stroke oil.

Recommended Fuel and Oil

Gasoline: Use unleaded gasoline with an octane rating of 89 or higher. Never use E10 or E15 gasoline, as the ethanol content can damage the fuel system components.
2-Stroke Oil: Use a high-quality, air-cooled 2-stroke engine oil specifically designed for chainsaws and other 2-stroke power equipment. Stihl manufactures its own brand of 2-stroke oil, which is highly recommended.

The Correct Mixing Ratio

The standard Stihl MS250 fuel mixture is 50:1. This means:

50 parts gasoline to 1 part 2-stroke oil.

To achieve this ratio, you will need a measuring container or a dedicated fuel mixing bottle.

Example Mixing Ratios:

Fuel Amount (Gallons)	Fuel Amount (Liters)	2-Stroke Oil Amount (oz)	2-Stroke Oil Amount (ml)
1	~3.785	2.6	~76.8
2	~7.570	5.1	~153.6
2.5	~9.463	6.4	~192.0
5	~18.927	12.8	~384.0

Important Mixing Tips:

Mix in a separate container: Never mix directly in the chainsaw’s fuel tank.
Add oil first: Pour the oil into the container, then add the gasoline. This helps ensure a thorough mix.
Shake well: Shake the container vigorously for at least 30 seconds to ensure the oil and gas are fully combined.
Only mix what you need: Fuel mixture degrades over time. Only mix enough for immediate use.
Use fresh fuel: Stale fuel can cause starting problems and engine damage.

Preparing for the First Start: Safety First!

Stihl MS250 safety is paramount. Before you attempt to start the saw, ensure you are prepared and protected.

Essential Safety Gear

Never operate a chainsaw without the following personal protective equipment (PPE):

Chainsaw Safety Helmet: Protects your head from falling branches and debris.
Eye Protection: Safety glasses or goggles to shield your eyes from sawdust and flying chips.
Hearing Protection: Earplugs or earmuffs to prevent hearing damage from the loud engine noise.
Chainsaw Gloves: Provide a better grip and protect your hands.
Chainsaw Chaps or Pants: Made of special material that can stop a moving chain, preventing serious leg injuries.
Steel-Toed Boots: Protect your feet from dropped logs or the chainsaw itself.

Choosing a Safe Starting Location

Clear Area: Find a flat, stable surface away from people, animals, and flammable materials.
No Obstructions: Ensure there are no branches, vines, or other obstacles around you that could snag the chain or bar.
Good Lighting: Operate in daylight or well-lit areas.

The Step-by-Step Guide to Starting Your Stihl MS250

Now for the moment of truth – getting your Stihl MS250 running! Follow these steps precisely for a safe and successful start.

Step 1: Activate the Chain Brake

Push Forward: The chain brake lever is located in front of the top handle. Push this lever forward towards the guide bar until it locks into place. This is a crucial safety step.

Step 2: Engage the Choke

Locate the Choke Lever: On the engine housing, you’ll find the choke lever.
Full Choke: For a cold engine, move the choke lever to the “choke” or “start” position. This enriches the fuel mixture for easier starting.

Step 3: Set the Throttle Lock

Push Throttle Trigger: Press the throttle trigger completely in.
Engage Throttle Lock: While holding the throttle trigger in, push down on the throttle lock lever (a small lever above the trigger) with your thumb.
Release Throttle Trigger: The throttle lock will now hold the throttle in the “fast idle” position, which is necessary for starting with the choke engaged. You’ll see the throttle trigger stay slightly depressed.

Step 4: Prime the Engine (If Equipped)

Locate the Primer Bulb: On the carburetor, you’ll see a small, clear rubber bulb.
Press Several Times: Press the primer bulb firmly several times until you see fuel circulating in it. This pushes fuel directly into the carburetor, aiding ignition.

Step 5: Engage the “Master Control Lever” (If Applicable)

Move to Cold Start: Many Stihl chainsaws have a “Master Control Lever” that combines the choke and throttle lock. If your MS250 has this, move the lever to the cold start position. This automatically engages the choke and fast idle.

Step 6: Pull the Starter Cord

Firm Grip: Grasp the starter cord handle firmly with your hand.
Smooth, Steady Pull: Pull the starter cord out with a strong, steady motion until you feel resistance. Then, give it a sharp, decisive tug.
Repeat: You may need to repeat this process several times. You’re aiming to get the engine to “cough” or “pop,” indicating it’s trying to start.

Step 7: Disengage the Choke

Listen for a “Pop”: Once you hear the engine “pop,” it’s ready for the choke to be disengaged.
Move Choke Lever: Move the choke lever back to the “run” or “half-choke” position. If your saw has a Master Control Lever, move it back to the normal running position.
Release Throttle Lock: The throttle lock will automatically disengage when you release the throttle trigger.

Step 8: Pull the Starter Cord Again

One or Two Pulls: With the choke disengaged, give the starter cord another one or two pulls. The engine should now start and run.

Step 9: Allow the Chainsaw to Warm Up

Let it Idle: Once the engine starts, let it idle for a short period (30 seconds to a minute). This allows the engine to warm up and the oil to circulate properly.
Disengage Chain Brake: Carefully push the chain brake lever back towards the handle to disengage it.

Congratulations! Your Stihl MS250 should now be running.

Stihl MS250 Operation: Using Your Chainsaw Safely and Effectively

Now that your chainsaw is running, it’s time to talk about Stihl MS250 operation. This involves more than just cutting; it’s about responsible use.

Basic Cutting Techniques

Grip: Hold the chainsaw with both hands, your left hand on the front handle and your right hand on the rear handle. Wrap your thumbs around the handles for a secure grip.
Body Position: Stand with your feet shoulder-width apart for a stable stance. Never stand directly behind the saw.
Cutting: Let the saw do the work. Apply steady pressure and guide the saw through the wood. Avoid forcing it.
Kickback: Be aware of kickback, the dangerous upward and backward motion of the guide bar that can occur if the nose of the bar strikes an object. Always maintain a firm grip and be mindful of where the bar tip is. The chain brake is your primary defense against kickback.

Using the Chain Brake

During Operation: Always have the chain brake engaged when moving between cuts, starting the saw, or when the saw is not actively cutting.
Accidental Activation: If the chain brake activates during cutting, stop the engine immediately.

Stihl MS250 Maintenance: Keeping Your Saw in Top Shape

Regular Stihl MS250 maintenance is essential for its performance, longevity, and your safety.

Daily Checks

Chain Tension: Check and adjust as needed.
Chain Sharpness: A dull chain will require more force and reduce cutting efficiency.
Bar Groove: Clean out sawdust and debris from the guide bar groove.
Air Filter: Check for dirt and debris.
Spark Plug: Ensure it’s clean and properly gapped.
Fasteners: Check that all nuts and bolts are tight.
Chain Brake: Ensure it functions correctly.

Air Filter Cleaning

A clogged air filter restricts airflow to the engine, reducing power and potentially causing damage.

Locate the Air Filter Cover: Typically, this is a knob or latch on the top of the engine housing.
Remove the Cover: Unscrew or unlatch the cover.
Remove the Filter: Carefully remove the air filter.
Clean: Tap the filter gently to remove loose debris. For a more thorough cleaning, wash it in warm, soapy water. Rinse it thoroughly and let it dry completely before reinstalling. Never use compressed air on a filter unless directed by the manual, as it can damage the filter media.
Replace if Damaged: If the filter is torn or damaged, replace it with a new one.
Reinstall: Place the clean, dry filter back into its housing and secure the cover.

Spark Plug Maintenance

The spark plug ignites the fuel-air mixture. A fouled or worn spark plug can lead to starting problems and poor engine performance.

Remove Spark Plug: Use the spark plug wrench from your tool kit to remove the spark plug.
Inspect: Check for carbon buildup, oil deposits, or damage to the electrode.
Clean: If dirty, clean the plug with a wire brush.
Gap: Check the gap between the electrodes using a feeler gauge. The correct gap for the MS250 is typically 0.020 inches (0.5 mm). Refer to your owner’s manual for the exact specification.
Replace: If the spark plug is worn or damaged, replace it with a new one of the correct type (e.g., NGK BPMR7A).
Reinstall: Screw the spark plug back in by hand to avoid cross-threading, then tighten it with the wrench.

Cleaning the Guide Bar and Sprocket

Remove Bar and Chain: After completing your work, remove the guide bar and chain.
Clean Bar Groove: Use a small brush or a thin flathead screwdriver to clean out the groove of the guide bar.
Clean Sprocket: Remove any sawdust or debris around the clutch sprocket.
Check Sprocket Wear: Inspect the sprocket for wear. If the teeth are significantly worn, it may need replacement.
Oil Bar: Ensure the oiler hole on the guide bar is clear.

Stihl MS250 Troubleshooting: Common Problems and Solutions

Even with proper care, you might encounter issues. Here’s some common Stihl MS250 troubleshooting:

Chainsaw Won’t Start

Check Fuel: Is there enough fresh, correctly mixed fuel in the tank?
Choke Position: Is the choke set correctly for a cold start?
Spark Plug: Is it fouled or wet? Try drying it or replacing it.
Air Filter: Is it clogged?
Primer Bulb: Is it working and showing fuel circulation?
Ignition: Check if the spark plug is sparking by grounding it against the engine block while pulling the cord (use insulated pliers!). If no spark, the spark plug, ignition coil, or ignition module might be faulty.
Carburetor: If all else fails, the carburetor might need cleaning or adjustment.

Chainsaw Starts but Stalls or Runs Poorly

Fuel Mixture: Incorrect ratio or stale fuel.
Air Filter: Clogged air filter.
Spark Plug: Fouled or improperly gapped.
Fuel Filter: A dirty fuel filter in the tank can restrict fuel flow.
Carburetor: May need cleaning or adjustment.

Chain Not Oiling

Check Oil Tank: Is the chain oil tank full?
Oiler Hole: Is the oiler hole in the guide bar clear?
Oil Pump: The internal oil pump might be clogged or malfunctioning.
Guide Bar: Ensure it’s not blocked by debris.

Stihl MS250 Parts: Replacing Worn Components

Over time, certain Stihl MS250 parts will wear out and need replacement.

Saw Chain: Chains need sharpening and eventual replacement. Look for signs of worn or damaged teeth.
Guide Bar: Bars can wear down, especially if not oiled properly or if used with a misaligned chain. Replace if the groove becomes excessively wide or the rails are damaged.
Sprocket: The clutch sprocket wears with use and needs to be replaced when teeth become too short or pointed.
Air Filter: While cleanable, they eventually need replacing.
Spark Plug: A regular wear item.
Fuel Filter: Should be replaced periodically.

When sourcing Stihl MS250 parts, always opt for genuine Stihl parts or high-quality aftermarket alternatives to ensure compatibility and performance.

Frequently Asked Questions (FAQ)

Q1: What is the best fuel mixture for a Stihl MS250?
A: The recommended fuel mixture for a Stihl MS250 is 50:1, which is 50 parts gasoline to 1 part high-quality air-cooled 2-stroke engine oil. Always use unleaded gasoline with an octane rating of 89 or higher, and avoid E10 or E15 fuels.

Q2: How do I adjust the chain tension on my Stihl MS250?
A: To adjust the chain tension, loosen the bar nuts slightly. Then, turn the chain tensioning screw (usually located on the side or front of the saw near the bar) clockwise to tighten the chain or counter-clockwise to loosen it. The chain should be snug but still be able to be rotated by hand.

Q3: My Stihl MS250 won’t start. What should I check?
A: First, ensure you have fresh, correctly mixed fuel. Check that the choke is engaged for a cold start and that the throttle lock is engaged. Verify the spark plug is clean and properly gapped. Make sure the air filter isn’t clogged. If the engine “coughs” but won’t start, disengage the choke and try again.

Q4: How often should I sharpen the chain on my Stihl MS250?
A: The frequency of chain sharpening depends on usage and the type of wood being cut. A general guideline is to sharpen the chain when it starts to produce fine sawdust instead of coarse chips, or when you notice you need to force the saw through the wood.

Q5: Can I use a different brand of 2-stroke oil with my Stihl MS250?
A: While you can use other high-quality air-cooled 2-stroke engine oils, Stihl recommends using their own branded 2-stroke oil for optimal performance and engine protection. If using another brand, ensure it is specifically designed for air-cooled 2-stroke engines and meets the correct specifications.

By following these detailed steps for Stihl MS250 setup, Stihl MS250 assembly, Stihl MS250 first start, and understanding proper Stihl MS250 operation, Stihl MS250 maintenance, Stihl MS250 fuel mixture, Stihl MS250 chain tension, and Stihl MS250 safety, you’ll be well-equipped to use your chainsaw effectively and safely for years to come. Remember to always consult your owner’s manual for specific instructions and recommendations related to your Stihl MS250.