Stihl 028 Wood Boss Carburetor Replacement (5 Pro Tips)
Replacing a carburetor on your Stihl 028 Wood Boss is a task any homeowner can tackle with the right knowledge and a little patience, saving you time and money.
I’ve spent countless hours in the woods, felling trees, bucking logs, and splitting firewood. Over the years, I’ve become intimately familiar with the Stihl 028 Wood Boss. It’s a reliable workhorse, but like any machine, it requires maintenance. One of the most common issues I’ve encountered is carburetor problems. A faulty carb can lead to hard starting, poor idling, and a general lack of power. Replacing it isn’t as daunting as it might seem. I’m going to share my top 5 pro tips to guide you through the process, ensuring a smooth and successful carburetor replacement.
Understanding the Stihl 028 Wood Boss Carburetor
Before diving into the replacement process, it’s crucial to understand the role of the carburetor and why it might need replacing.
What is a Carburetor?
The carburetor’s primary function is to mix air and fuel in the correct ratio to create a combustible mixture for the engine. It’s a vital component for proper engine operation. Without a functioning carburetor, your chainsaw won’t run efficiently, if at all.
Why Replace the Carburetor?
Several factors can lead to carburetor failure:
- Old Fuel: Ethanol-blended fuels can degrade over time, leaving behind gummy deposits that clog the carburetor’s tiny passages. I always recommend using fuel stabilizer, especially if the saw will sit unused for more than a month.
- Dirt and Debris: Dirt and debris can enter the fuel system and clog the carburetor. A clean air filter and fuel filter are essential for preventing this.
- Wear and Tear: Over time, the carburetor’s internal components can wear out, leading to poor performance. The diaphragm, in particular, can become brittle and cracked.
- Damage: Physical damage to the carburetor can also necessitate replacement.
Key Terms
- Green Wood: Freshly cut wood with a high moisture content (often above 30%).
- Seasoned Wood: Wood that has been air-dried to a lower moisture content (typically below 20%), making it ideal for burning.
- Fuel Filter: A small filter located inside the fuel tank that prevents debris from entering the fuel line.
- Air Filter: A filter that prevents dirt and debris from entering the engine.
- Diaphragm: A flexible membrane inside the carburetor that regulates fuel flow.
- Idle Speed: The engine’s speed when the throttle is released.
- High-Speed Needle: An adjustment screw on the carburetor that controls the fuel mixture at high engine speeds.
- Low-Speed Needle: An adjustment screw on the carburetor that controls the fuel mixture at low engine speeds.
- Choke: A mechanism that restricts airflow to the carburetor, enriching the fuel mixture for starting a cold engine.
Pro Tip 1: Preparation is Key
Proper preparation is crucial for a successful carburetor replacement. This involves gathering the necessary tools, understanding the process, and ensuring a clean and organized workspace.
Gathering the Right Tools
- New Carburetor: Purchase a replacement carburetor specifically designed for the Stihl 028 Wood Boss. I’ve found that aftermarket carburetors can be just as reliable as OEM parts, but it’s important to choose a reputable brand.
- Screwdrivers: You’ll need both flathead and Phillips head screwdrivers of various sizes. A small screwdriver set is particularly useful for adjusting the carburetor.
- Pliers: Pliers are helpful for disconnecting fuel lines and removing stubborn parts.
- Socket Set: A socket set with various sizes will be needed for removing the air filter cover and other components.
- Carburetor Cleaner: Carburetor cleaner is essential for cleaning any remaining parts and ensuring a smooth installation.
- New Fuel Filter: I always recommend replacing the fuel filter when replacing the carburetor. It’s a cheap insurance policy against future problems.
- New Air Filter: Similar to the fuel filter, a new air filter will help prevent dirt and debris from entering the engine.
- Gasket Set: A new gasket set will ensure a proper seal between the carburetor and the engine.
- Spark Plug Wrench: While not directly related to the carburetor, it’s always a good idea to check the spark plug while you’re working on the saw.
- Shop Rags: Shop rags are essential for cleaning up spills and wiping down parts.
- Work Gloves: Protect your hands from dirt and grime.
- Safety Glasses: Safety glasses are crucial for protecting your eyes from debris.
- Camera or Smartphone: Take photos of each step of the disassembly process. This will be invaluable when you’re reassembling the saw.
- Parts Tray: A parts tray will help you keep track of all the small parts and prevent them from getting lost.
Understanding the Process
Before you start taking things apart, take some time to familiarize yourself with the process. Watch videos, read articles, and study diagrams of the Stihl 028 Wood Boss carburetor. Understanding how the carburetor works and how it’s connected to the engine will make the replacement process much easier.
Creating a Clean Workspace
A clean and organized workspace is essential for a successful carburetor replacement. Clear off a table or workbench and cover it with a clean cloth or paper towels. This will help prevent dirt and debris from contaminating the carburetor.
My Personal Experience
I remember one time I was replacing a carburetor on a Stihl 028 in the middle of the woods. I didn’t have all the right tools, and the workspace was far from ideal. As a result, the process took much longer than it should have, and I ended up losing a few small parts. Since then, I’ve learned the importance of proper preparation.
Pro Tip 2: Disassembly with Precision
Disassembly is a critical step in the carburetor replacement process. It’s important to take your time, be careful, and document each step.
Removing the Air Filter Cover
Start by removing the air filter cover. This is usually held in place by a few screws or clips. Use the appropriate screwdriver or socket to remove the screws or clips. Once the cover is removed, you’ll have access to the air filter.
Removing the Air Filter
Remove the air filter and set it aside. If the air filter is dirty, replace it with a new one.
Disconnecting the Fuel Line
Locate the fuel line that connects to the carburetor. Use pliers to gently disconnect the fuel line from the carburetor. Be careful not to damage the fuel line. If the fuel line is brittle or cracked, replace it with a new one. I typically use a fuel line pick to gently pry the fuel line off the carburetor nipple.
Disconnecting the Throttle Linkage
The throttle linkage connects the throttle trigger to the carburetor. Disconnect the throttle linkage from the carburetor. This is usually done by removing a small clip or screw. Again, taking a picture before disconnecting this helps immensely.
Removing the Carburetor
Once the fuel line and throttle linkage are disconnected, you can remove the carburetor from the engine. The carburetor is usually held in place by a few bolts or screws. Use the appropriate screwdriver or socket to remove the bolts or screws. Once the bolts or screws are removed, carefully remove the carburetor from the engine.
Inspecting the Intake Manifold
Before installing the new carburetor, inspect the intake manifold for any cracks or damage. The intake manifold is the part of the engine that the carburetor attaches to. If the intake manifold is damaged, it will need to be replaced. I’ve seen instances where a cracked intake manifold caused the saw to run lean, eventually leading to engine damage.
Documenting the Process
As you disassemble the carburetor, take photos of each step. This will be invaluable when you’re reassembling the saw. Pay close attention to the order in which the parts are removed and how they are connected. I also like to use a parts tray with labeled compartments to keep everything organized.
My Personal Experience
I once forgot to disconnect the throttle linkage before trying to remove the carburetor. As a result, I ended up damaging the throttle linkage. It’s a mistake I won’t make again. Taking photos and being methodical is key.
Pro Tip 3: Cleaning and Inspection
Before installing the new carburetor, it’s important to clean the surrounding area and inspect the remaining components. This will help ensure a smooth and trouble-free installation.
Cleaning the Mounting Surface
Clean the mounting surface on the engine where the carburetor will be installed. Use a shop rag and carburetor cleaner to remove any dirt, debris, or old gasket material. A clean mounting surface will ensure a proper seal between the carburetor and the engine.
Inspecting the Fuel Line
Inspect the fuel line for any cracks, leaks, or damage. If the fuel line is damaged, replace it with a new one. A damaged fuel line can cause fuel leaks and poor engine performance.
Inspecting the Fuel Filter
Inspect the fuel filter for any clogs or damage. If the fuel filter is clogged or damaged, replace it with a new one. A clogged fuel filter can restrict fuel flow and cause poor engine performance.
Inspecting the Air Filter Housing
Inspect the air filter housing for any cracks or damage. If the air filter housing is damaged, replace it with a new one. A damaged air filter housing can allow dirt and debris to enter the engine.
Cleaning the Surrounding Area
Clean the surrounding area around the carburetor. This will help prevent dirt and debris from entering the engine when you install the new carburetor. I use a shop vac to remove any loose debris.
My Personal Experience
I once installed a new carburetor without cleaning the mounting surface. As a result, the carburetor didn’t seal properly, and the saw ran poorly. I had to remove the carburetor and clean the mounting surface before reinstalling it. It was a frustrating experience that taught me the importance of cleaning and inspection.
Pro Tip 4: Installation with Care
Installing the new carburetor requires care and attention to detail. Follow these steps to ensure a proper installation.
Installing the New Gaskets
Install the new gaskets that came with the carburetor. Make sure the gaskets are properly aligned and seated. The gaskets will create a seal between the carburetor and the engine. I often apply a thin layer of grease to the gaskets to help them seal properly.
Attaching the Carburetor
Carefully attach the new carburetor to the engine. Make sure the carburetor is properly aligned with the mounting holes. Install the bolts or screws that hold the carburetor in place. Tighten the bolts or screws to the manufacturer’s specifications. Over-tightening can damage the carburetor or the engine.
Reconnecting the Throttle Linkage
Reconnect the throttle linkage to the carburetor. Make sure the throttle linkage is properly adjusted. A properly adjusted throttle linkage will ensure that the throttle trigger controls the engine speed correctly. Refer to the photos you took during disassembly to ensure proper re-connection.
Reconnecting the Fuel Line
Reconnect the fuel line to the carburetor. Make sure the fuel line is securely attached. A loose fuel line can cause fuel leaks and poor engine performance. I use fuel line clamps to ensure a secure connection.
Installing the Air Filter
Install the air filter. Make sure the air filter is properly seated in the air filter housing.
Installing the Air Filter Cover
Install the air filter cover. Make sure the air filter cover is securely attached.
Double-Checking Connections
Before starting the engine, double-check all the connections to make sure they are secure. This includes the fuel line, throttle linkage, and air filter cover.
My Personal Experience
I once forgot to tighten the bolts that held the carburetor in place. As a result, the carburetor came loose while I was using the saw. It was a dangerous situation that could have been avoided if I had double-checked the connections.
Pro Tip 5: Adjustment and Fine-Tuning
Once the new carburetor is installed, it’s important to adjust it properly. This will ensure that the engine runs smoothly and efficiently.
Starting the Engine
Start the engine and let it warm up for a few minutes.
Adjusting the Idle Speed
Adjust the idle speed screw until the engine idles smoothly without stalling. The idle speed should be set to the manufacturer’s specifications. You can usually find this information in the owner’s manual or online.
Adjusting the High-Speed Needle
Adjust the high-speed needle until the engine runs smoothly at full throttle. The high-speed needle controls the fuel mixture at high engine speeds. If the engine is running lean (too much air), it will sound raspy and may overheat. If the engine is running rich (too much fuel), it will smoke excessively and may bog down.
Adjusting the Low-Speed Needle
Adjust the low-speed needle until the engine idles smoothly and accelerates quickly. The low-speed needle controls the fuel mixture at low engine speeds. If the engine is running lean, it will hesitate when you accelerate. If the engine is running rich, it will bog down when you accelerate.
Fine-Tuning
Fine-tune the carburetor adjustments until the engine runs smoothly and efficiently at all engine speeds. This may take some trial and error. I often use a tachometer to ensure that the engine is running at the correct RPM.
Checking the Spark Plug
After adjusting the carburetor, check the spark plug. The spark plug should be a light tan color. If the spark plug is black or oily, the engine is running rich. If the spark plug is white or gray, the engine is running lean.
Monitoring Performance
Monitor the engine’s performance over time. If you notice any problems, such as hard starting, poor idling, or a lack of power, readjust the carburetor.
My Personal Experience
I once spent hours trying to adjust a carburetor on a Stihl 028 Wood Boss. I couldn’t get it to run properly. I finally realized that the problem wasn’t the carburetor; it was the spark plug. Replacing the spark plug solved the problem. It taught me the importance of checking all the components when troubleshooting engine problems.
Bonus Tip: Fuel and Maintenance
Using the correct fuel and performing regular maintenance are crucial for keeping your Stihl 028 Wood Boss running smoothly.
Using the Right Fuel
Use high-quality gasoline with an octane rating of 89 or higher. I recommend using ethanol-free gasoline whenever possible. Ethanol can damage the carburetor and other engine components. Always mix the gasoline with the correct amount of two-cycle oil, as specified by the manufacturer. I prefer using Stihl’s own two-cycle oil.
Regular Maintenance
Perform regular maintenance on your Stihl 028 Wood Boss. This includes cleaning the air filter, replacing the fuel filter, and checking the spark plug. Regular maintenance will help prevent problems and extend the life of your chainsaw.
Sharpening the Chain
Keep the chain sharp. A sharp chain will cut more efficiently and reduce the strain on the engine. I use a chainsaw file to sharpen the chain regularly.
Cleaning the Saw
Clean the saw after each use. This will help prevent dirt and debris from building up and causing problems.
Storing the Saw
Store the saw in a dry place. This will help prevent rust and corrosion. I drain the fuel tank before storing the saw for extended periods.
Case Study: Reviving a Neglected Stihl 028
I once purchased a used Stihl 028 Wood Boss that had been neglected for years. The carburetor was completely clogged, and the engine wouldn’t start. I replaced the carburetor, fuel filter, and air filter. I also cleaned the spark plug and sharpened the chain. After a few adjustments, the saw started right up and ran like new. It was a rewarding experience that demonstrated the importance of proper maintenance and repair.
Strategic Advantages of Proper Maintenance
- Increased Efficiency: A well-maintained chainsaw will cut more efficiently, saving you time and fuel.
- Reduced Downtime: Regular maintenance will help prevent problems and reduce downtime.
- Extended Lifespan: Proper maintenance will extend the life of your chainsaw.
- Improved Safety: A well-maintained chainsaw is safer to use.
Next Steps
Now that you’ve learned how to replace the carburetor on your Stihl 028 Wood Boss, it’s time to put your knowledge into practice. Gather the necessary tools and materials, and follow the steps outlined in this guide. Remember to take your time, be careful, and document each step. With a little patience and effort, you can successfully replace the carburetor and get your chainsaw running smoothly again. If you find any step difficult, there are many helpful videos on YouTube.
Replacing the carburetor on your Stihl 028 Wood Boss is a manageable task that can save you money and keep your saw running strong for years to come. By following these pro tips, you can tackle this project with confidence and get back to felling trees and splitting firewood.
