How I Learned to Adjust a Husqvarna Chainsaw Carburetor

It was a crisp Saturday morning. I had a tall stack of logs in the driveway and a long day of work ahead. I grabbed my saw, ready to cut.

I pulled the cord. The engine sputtered. I pulled again. It started, but as soon as I hit the gas, it died. The silence was loud. I could smell unburnt fuel. I felt the heat rise in my face. It wasn’t the wood that was the problem. It was my tool.

I realized I had to adjust a Husqvarna chainsaw carburetor myself. I was nervous. I didn’t want to break it. But after some trial and error, I found it is not magic. It is just listening.

Here is how I fixed my saw and got back to work.

The Mistake I Made First

Before I touched a single screw, I learned a hard lesson. Never tune a dirty saw.

Years ago, I tuned a saw that had a clogged air filter. It ran great that day. But when I cleaned the filter later, the saw got too much air. It ran too hot and I almost ruined the engine.

So, standing in my driveway, I did this first:

1. I cleaned the air filter. I washed it with warm soapy water.
2. I checked the gas. I made sure the tank had fresh mix.
3. I warmed it up. I let the engine idle for five minutes. You cannot tune a cold engine.

The Three Magic Letters

On the side of my saw, I saw three holes. They are marked L, H, and T.

• L (Low): Helps the saw start and speed up.
• H (High): Gives the saw power while cutting.
• T (Idle): Keeps the saw running when you let go of the trigger.

Step 1: Fixing the Bog (The “L” Screw)

My main issue was the “bog.” I would pull the trigger, and the saw would gasp for air.

To fix this, I used the L screw.

1. I let the saw idle.
2. I slowly turned the L screw clockwise. The engine speed went up. It started to sound like it was racing.
3. Once I heard that high speed, I stopped.
4. Then, I turned the screw back counter-clockwise just a tiny bit (about 1/4 turn). The engine slowed down and sounded deeper.

The Test: I snapped the throttle trigger fast.

My Result: The saw roared instantly. No lag. If it had hesitated, I would have turned the screw a little more to the left (counter-clockwise).

Step 2: Safety First (The “T” Screw)

After the first step, I noticed something scary. The chain was spinning while the saw sat on the ground. That is dangerous.

I went to the T screw. This one is easy.

1. I watched the chain.
2. I turned the T screw to the left (counter-clockwise).
3. I kept turning until the chain stopped moving completely.

I made sure the engine still ran smoothly. I found the sweet spot where the engine purred, but the chain stayed still.

Step 3: The High Speed Hum (The “H” Screw)

This part made me sweat. The H screw controls the fuel at full power. If you get this wrong, you can burn up the piston.

I held the throttle wide open. The saw screamed. It was a high, clean whine. That sounds fast, but it is actually bad. It means the engine is starving for gas.

I turned the H screw to the left very slowly. I listened for a specific sound. Old woodcutters call it “burbling.” It sounds a bit rough, like a boat motor clearing its throat.

• The Scream: Too lean. Too hot. Danger.
• The Burble: Just right.

When I heard that rough burble at full speed, I knew I was safe. I tested it on a log. As soon as the chain hit the wood, the burble vanished. The saw pulled hard and smooth. It was perfect.

My Quick Cheat Sheet

Here is a table of what I look for when my saw acts up.

What I Hear/See	The Likely Problem	My Quick Fix
Saw dies when I hit gas	L Screw is too lean.	Turn L screw Left.
Chain spins at idle	T Screw is too fast.	Turn T screw Left.
Saw screams / gets hot	H Screw is too lean.	Turn H screw Left.
Lots of smoke	H Screw is too rich.	Turn H screw Right.

Final Thoughts

By the time I finished, the sun was high. I wiped the sawdust off the cover. I pulled the cord one last time. It started on the first pull.

The saw felt like new. I cut through that oak pile in record time. There is a real pride in fixing your own tools. You save money, but you also learn to trust your hands.

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