Craftsman 358 Chainsaw Carburetor Replacement (Pro Repair Tips)

Let’s talk about Craftsman 358 chainsaw carburetor replacement, and some pro repair tips.

I’ve spent decades in the woods, from felling massive oaks to prepping cords of firewood for the long winter months. I’ve seen it all – chainsaws that start on the first pull and others that refuse to cooperate no matter what. And let me tell you, a finicky carburetor is often the culprit.

There’s a common myth that chainsaws are indestructible beasts of burden. People think they can run them hard, neglect maintenance, and they’ll keep chugging along forever. That’s simply not true. Like any precision machine, a chainsaw relies on a finely tuned engine, and the carburetor is a critical component. Over time, fuel varnish builds up, gaskets dry out, and the carburetor simply can’t deliver the correct fuel-air mixture. This leads to hard starting, stalling, poor performance, and ultimately, a dead chainsaw. Replacing the carburetor is often the most cost-effective solution, especially on a reliable machine like the Craftsman 358.

The user intent behind searching for “Craftsman 358 Chainsaw Carburetor Replacement (Pro Repair Tips)” is clear: someone is experiencing carburetor problems with their Craftsman 358 chainsaw and wants to fix it themselves. They’re looking for a step-by-step guide, along with expert advice to ensure a successful repair. They likely want to save money on professional repair costs and gain a better understanding of their chainsaw’s inner workings.

So, let’s dive into the world of chainsaw carburetors. I’ll guide you through the replacement process, sharing my personal experiences and pro tips along the way.

Craftsman 358 Chainsaw Carburetor Replacement: A Step-by-Step Guide with Pro Repair Tips

Before we begin, let’s define some key terms:

• Carburetor: The component that mixes air and fuel in the correct proportions to create a combustible mixture for the engine.
• Fuel-Air Mixture: The ratio of gasoline to air that the engine needs to run efficiently.
• Diaphragm: A flexible membrane inside the carburetor that regulates fuel flow.
• Gaskets: Seals that prevent air leaks between carburetor components.
• Idle Speed: The engine speed when the throttle is released.
• High-Speed Needle: Adjustment screw that controls the fuel mixture at high engine speeds.
• Low-Speed Needle: Adjustment screw that controls the fuel mixture at idle and low engine speeds.

Step 1: Diagnosis – Is it Really the Carburetor?

Before you start tearing things apart, it’s crucial to confirm that the carburetor is indeed the problem. Other issues can mimic carburetor problems, leading you down a frustrating path.

Common Symptoms of a Faulty Carburetor:

• Hard Starting: The engine cranks but refuses to start, or takes excessive cranking to get going.
• Stalling: The engine starts and runs briefly, then stalls.
• Poor Idle: The engine idles roughly or stalls at idle.
• Lack of Power: The engine lacks power, especially under load.
• Flooding: The engine floods easily, with excessive fuel in the cylinder.
• Black Smoke: Excessive black smoke from the exhaust, indicating a rich fuel mixture (too much fuel).

Troubleshooting Before Replacement:

1. Check the Fuel: Ensure you have fresh, clean fuel mixed with the correct two-stroke oil ratio (typically 50:1). Old or contaminated fuel is a common culprit. I once spent an hour troubleshooting a chainsaw only to discover the gas can had water in it. Always use fresh fuel!
2. Inspect the Fuel Filter: A clogged fuel filter restricts fuel flow to the carburetor. Locate the fuel filter inside the fuel tank, attached to the fuel line. If it’s dirty, replace it. They’re inexpensive and can save you a lot of headaches.
3. Check the Spark Plug: A fouled spark plug can cause starting and running problems. Remove the spark plug and inspect it. It should be clean and dry. If it’s wet or oily, clean it or replace it. Ensure the spark plug gap is correct (typically 0.025-0.030 inches for a Craftsman 358).
4. Inspect the Air Filter: A dirty air filter restricts airflow to the carburetor, causing a rich fuel mixture. Clean or replace the air filter.
5. Check for Air Leaks: Air leaks around the carburetor or intake manifold can disrupt the fuel-air mixture. Inspect the intake boot (the rubber connector between the carburetor and the engine) for cracks or damage. Spray carburetor cleaner around the intake boot while the engine is running. If the engine speed changes, you likely have an air leak.
6. Try Adjusting the Carburetor Needles: The carburetor has two adjustment screws: the high-speed needle (marked “H”) and the low-speed needle (marked “L”). These screws control the fuel mixture. Note: some carburetors have fixed jets and are non-adjustable. Before making any adjustments, note the current position of the needles. Gently turn each needle in until it seats (don’t overtighten!), then count the number of turns out to its original position. Now, try adjusting the needles slightly (1/8 turn at a time) to see if it improves the engine’s performance. If this doesn’t help, and you’ve ruled out other issues, it’s likely time for a carburetor replacement.

Personal Story: I once had a Craftsman 358 that was running poorly. I went through all the troubleshooting steps, but nothing seemed to fix it. I was convinced it was the carburetor. As a last resort, I decided to check the compression. Turns out, the engine had low compression, which was causing the same symptoms as a bad carburetor. Don’t assume it’s always the carburetor!

Step 2: Gathering Your Tools and Supplies

Before you start, gather everything you’ll need. This will save you time and frustration.

Tools Required:

• Screwdrivers: A flathead screwdriver and a Phillips head screwdriver.
• Pliers: For removing fuel lines and other small parts.
• Socket Set: A small socket set may be needed for removing the carburetor mounting bolts.
• Carburetor Adjustment Tool: A special tool may be required to adjust the carburetor needles (some carburetors have tamper-proof caps).
• Pick or Small Screwdriver: For removing fuel lines and diaphragms.
• Clean Rags: For wiping up fuel and cleaning parts.
• Carburetor Cleaner: For cleaning the carburetor and surrounding area.
• Compressed Air: For blowing out debris from the carburetor.
• Work Gloves: To protect your hands.
• Safety Glasses: To protect your eyes.

Supplies Required:

• New Carburetor: Make sure you order the correct carburetor for your Craftsman 358 model. Double-check the part number before ordering. I always recommend buying a genuine OEM (Original Equipment Manufacturer) carburetor or a reputable aftermarket brand. Cheap, no-name carburetors often have poor quality control and may not perform well.
• New Fuel Filter: Replace the fuel filter whenever you replace the carburetor.
• New Air Filter: Replace the air filter if it’s dirty or damaged.
• New Spark Plug: Replace the spark plug if it’s old or fouled.
• New Fuel Line (Optional): If the fuel lines are cracked or brittle, replace them.
• Gasket Sealer (Optional): Use a small amount of gasket sealer on the carburetor mounting surfaces to ensure a good seal.

Important Note: Work in a well-ventilated area, away from open flames or sparks. Gasoline is highly flammable.

Step 3: Removing the Old Carburetor

Now that you have your tools and supplies, it’s time to remove the old carburetor.

1. Disconnect the Spark Plug Wire: This is a crucial safety step. Disconnecting the spark plug wire prevents the engine from accidentally starting while you’re working on it.
2. Remove the Air Filter Cover and Air Filter: Remove the air filter cover and the air filter. Set them aside.
3. Disconnect the Fuel Line: Carefully disconnect the fuel line from the carburetor. Use pliers if necessary. Be prepared for some fuel to spill. Have a rag handy to wipe up any spills.
4. Disconnect the Throttle Linkage: The throttle linkage connects the throttle trigger to the carburetor. Disconnect the throttle linkage from the carburetor. Note how it’s connected so you can reassemble it correctly.
5. Remove the Choke Linkage (if applicable): Some Craftsman 358 models have a choke linkage. Disconnect the choke linkage from the carburetor.
6. Remove the Carburetor Mounting Bolts: Remove the bolts that hold the carburetor to the engine. These are usually located on the intake manifold.
7. Remove the Carburetor: Carefully remove the carburetor from the engine.
8. Inspect the Intake Manifold: Inspect the intake manifold for cracks or damage. If it’s damaged, replace it.

Pro Tip: Take pictures as you disassemble the carburetor. This will help you reassemble everything correctly.

Personal Story: I once forgot to disconnect the throttle linkage when removing a carburetor. I ended up bending the linkage and had to spend extra time straightening it out. Learn from my mistake!

Step 4: Installing the New Carburetor

With the old carburetor removed, it’s time to install the new one.

1. Clean the Mounting Surfaces: Clean the carburetor mounting surfaces on the engine and the intake manifold. Use carburetor cleaner and a clean rag.
2. Install the New Carburetor: Carefully install the new carburetor onto the intake manifold.
3. Install the Carburetor Mounting Bolts: Install the carburetor mounting bolts and tighten them securely. Don’t overtighten them.
4. Reconnect the Throttle Linkage: Reconnect the throttle linkage to the carburetor. Make sure it’s properly connected and moves freely.
5. Reconnect the Choke Linkage (if applicable): Reconnect the choke linkage to the carburetor.
6. Reconnect the Fuel Line: Reconnect the fuel line to the carburetor. Make sure it’s securely connected.
7. Install the Air Filter and Air Filter Cover: Install the air filter and the air filter cover.
8. Reconnect the Spark Plug Wire: Reconnect the spark plug wire.

Pro Tip: Apply a small amount of gasket sealer to the carburetor mounting surfaces to ensure a good seal.

Step 5: Adjusting the Carburetor

After installing the new carburetor, you’ll need to adjust it for optimal performance.

Important Note: Refer to your Craftsman 358 owner’s manual for specific carburetor adjustment instructions. The following is a general guideline.

1. Locate the Carburetor Adjustment Screws: The carburetor has two adjustment screws: the high-speed needle (marked “H”) and the low-speed needle (marked “L”). These screws control the fuel mixture. Note: some carburetors have fixed jets and are non-adjustable.
2. Initial Settings: As a starting point, turn both the high-speed and low-speed needles in until they seat (don’t overtighten!), then back them out 1 to 1.5 turns. This is just a starting point.
3. Start the Engine: Start the engine and let it warm up for a few minutes.
4. Adjust the Low-Speed Needle: Adjust the low-speed needle until the engine idles smoothly. If the engine stalls at idle, turn the low-speed needle out slightly. If the engine idles too fast, turn the low-speed needle in slightly.
5. Adjust the High-Speed Needle: Adjust the high-speed needle for optimal performance at high engine speeds. Run the engine at full throttle and listen for any signs of a lean or rich fuel mixture. A lean mixture (not enough fuel) will cause the engine to sound “screaming” or “whining.” A rich mixture (too much fuel) will cause the engine to produce black smoke and lack power. Adjust the high-speed needle until the engine runs smoothly at full throttle without any signs of a lean or rich mixture.
6. Fine-Tune the Idle Speed: After adjusting the high-speed and low-speed needles, you may need to fine-tune the idle speed. The idle speed screw is usually located near the throttle linkage. Adjust the idle speed screw until the engine idles at the correct speed (refer to your owner’s manual).

Pro Tip: Use a tachometer to accurately measure the engine speed. This will help you fine-tune the carburetor for optimal performance.

Personal Story: I once spent hours trying to adjust a carburetor without a tachometer. I was just guessing at the engine speed. Once I got a tachometer, it made the job much easier and I was able to get the engine running perfectly.

Step 6: Testing and Final Adjustments

After adjusting the carburetor, it’s important to test the chainsaw to make sure it’s running properly.

1. Start the Chainsaw: Start the chainsaw and let it warm up for a few minutes.
2. Test the Idle: Let the chainsaw idle for a few minutes. It should idle smoothly without stalling.
3. Test the Throttle Response: Quickly squeeze the throttle trigger. The engine should respond quickly and smoothly without hesitation.
4. Test the Cutting Performance: Cut a few pieces of wood to test the chainsaw’s cutting performance. It should cut smoothly and powerfully without stalling.
5. Make Final Adjustments: If the chainsaw is not running properly, make any necessary final adjustments to the carburetor.

Pro Tip: If you’re having trouble adjusting the carburetor, consult a qualified chainsaw mechanic.

Case Study: Reviving a Neglected Craftsman 358

I had a friend who inherited his grandfather’s old Craftsman 358 chainsaw. It had been sitting in a shed for years and wouldn’t start. He was about to throw it away, but I convinced him to let me take a look at it.

The first thing I did was drain the old fuel. It was thick and gummy. I replaced the fuel filter and spark plug. Then, I tried to start it, but it still wouldn’t start. I suspected the carburetor was the problem.

I removed the carburetor and disassembled it. It was completely clogged with varnish. I cleaned all the carburetor parts with carburetor cleaner and compressed air. I also replaced the carburetor diaphragm and gaskets.

After reassembling the carburetor, I installed it back on the chainsaw. I adjusted the carburetor needles and tried to start it. It started on the second pull!

The chainsaw ran rough at first, but after a few minutes of adjusting the carburetor, it smoothed out. I tested it by cutting a few pieces of wood. It cut like new!

My friend was amazed. He couldn’t believe that I had brought his grandfather’s old chainsaw back to life.

Lessons Learned:

• Old fuel is a common cause of carburetor problems.
• Cleaning the carburetor and replacing the diaphragm and gaskets can often restore a carburetor to good working order.
• Proper carburetor adjustment is essential for optimal chainsaw performance.

Strategic Advantages of DIY Carburetor Replacement

Replacing a carburetor yourself offers several strategic advantages:

• Cost Savings: You save money on professional repair costs. Chainsaw repair shops typically charge a significant amount for carburetor replacement, including labor and parts markup.
• Knowledge and Understanding: You gain a better understanding of your chainsaw’s inner workings. This knowledge can be valuable for future repairs and maintenance.
• Faster Turnaround Time: You can fix the chainsaw yourself in a matter of hours, rather than waiting days or weeks for a repair shop to get to it.
• Empowerment: You feel a sense of accomplishment and empowerment by fixing your own equipment.

Technical Details and Specifications

• Craftsman 358 Chainsaw Engine Displacement: Typically around 38-42cc, depending on the specific model.
• Carburetor Type: Walbro or Zama carburetor (check your specific model).
• Spark Plug Gap: 0.025-0.030 inches.
• Fuel Mixture Ratio: 50:1 (gasoline to two-stroke oil). Use a high-quality two-stroke oil.
• Carburetor Needle Adjustment: Initial settings: 1 to 1.5 turns out from seated position for both high-speed and low-speed needles. Fine-tune as needed.
• Estimated Repair Time: 1-2 hours for a beginner.
• Skill Level Required: Beginner to intermediate.
• Cost of Carburetor: $20-$50 for an aftermarket carburetor, $50-$100 for a genuine OEM carburetor.

Safety Considerations

• Always disconnect the spark plug wire before working on the chainsaw.
• Work in a well-ventilated area, away from open flames or sparks.
• Wear safety glasses and work gloves.
• Be careful when handling gasoline. It is highly flammable.
• If you are not comfortable performing this repair yourself, consult a qualified chainsaw mechanic.

Next Steps: Implementation Guidance

Now that you’ve learned how to replace a Craftsman 358 chainsaw carburetor, it’s time to put your knowledge into practice.

1. Gather your tools and supplies.
2. Order a new carburetor.
3. Follow the step-by-step instructions in this guide.
4. Take your time and be careful.
5. If you get stuck, consult a qualified chainsaw mechanic.

With a little patience and effort, you can successfully replace your chainsaw carburetor and get your Craftsman 358 running like new again. Remember to always prioritize safety and consult with a professional if you’re unsure about any aspect of the repair. Good luck, and happy sawing!

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