As a seasoned chainsaw operator, if you find your tool bogging down in the middle of a job, there’s nothing more frustrating than that. One of the common causes of chainsaw failure is a scored piston. Over time aluminum can build on the cylinder wall, affecting your tool’s cutting performance and even leading to engine damage.
But fear not! This guide will help you with chainsaw cylinder cleanup and honing. I’ll walk you through the process, from disassembling the cutting machine to using a honing tool and removing aluminum buildup from the cylinder walls.
You’ll also know the reasons behind piston scoring, how to identify it, and how much scoring is acceptable. In a short time, you’ll be back to felling trees like a pro. So grab your chainsaw, put on your flannel, and let’s get to honing!
How to Hone a Chainsaw Cylinder in 3 Simple Steps?
Honing the chainsaw cylinder requires removing the cylinder and piston from the tool. Next, you’ll need a honing tool to remove the aluminum buildup from the cylinder walls. But be careful not to remove too much.
Before I dive deeply into the honing process, let me clear the relationship between piston scoring and aluminum buildup. Both go hand in hand. When you use a chainsaw, small bits of aluminum from the piston can transfer to the cylinder wall, causing a buildup.
Conversely, scoring can create rough spots on the cylinder wall, trapping the aluminum particles and leading to more buildup. It’s a vicious cycle that can affect the longevity and performance of your machine. That’s why it’s crucial to address both issues when honing the STIHL chainsaw cylinder or any other brand’s cylinder.
Now, without further ado, let’s dive into the real stuff – cleaning and honing a chainsaw cylinder.
Chainsaw Cylinder Scoring Repair Method
Here’s how to clean the chainsaw cylinder and repair piston scoring:
Step 1: Preparation
Before the honing process, wear gloves and safety goggles to protect yourself against flying metal pieces. To hone the chainsaw cylinder, you’ll need to gather tools such as a piston stop, a honing tool, and a torque wrench. After you’ve done that, disassemble the chainsaw machine and remove the cylinder from the engine using a socket wrench.
Step 2: The Honing Process
Before honing, it’s vital to clean the cylinder thoroughly to remove aluminum transfer from the chainsaw cylinder or any debris. Use a specialized solution recommended by your cutting tool’s manufacturer.
Then proceed with inspecting the cylinder and piston for scoring damage. Next, apply honing oil on the cylinder and piston according to the manual. Then, use small honing tools like a honing pad or stone according to the size of the piston and cylinder to hone the cylinder and piston.
But be careful not to remove too much material. Rotate the honing tool back and forth and clean up the buildup according to the manufacturer’s manual.
Step 3: Reassembly
After honing, clean up the cylinder again to remove debris and replace the piston rings if damaged. Carefully reinstall the cylinder and use the torque wrench to tighten the cylinder properly. Then reassemble the chainsaw and adjust the carburetor accordingly to ensure the tool runs smoothly.
All done and dusted with the honing process. But let me explain the science behind what causes piston scoring and aluminum transfer. You can avoid these issues in the future with proper maintenance of your cutting tool.
What Causes Chainsaw Piston Scoring?
Piston scoring happens when the piston of a chainsaw repeatedly rubs against the cylinder wall, causing scratches and grooves on the piston’s surface. But what causes this disaster to happen? Let’s find out.
When you run your cutting machine for too long or at a high RPM, it generates heat. This causes the piston to expand and seize up in the cylinder.
When this happens, the piston rubs against the cylinder walls, causing those nasty scratches and grooves to appear. So, take little breaks between logging and avoid prolonged tool idling.
Poor lubrication is also a major factor. Your cutting machine will need proper lubrication to keep the piston moving smoothly. Without enough lubrication, the increased friction between the piston and the cylinder walls will lead to piston scoring. Now, you know why proper lubrication is necessary.
Wrong Fuel Mixture
Another potential cause of piston scoring is using the wrong fuel mixture. If you’re not mixing the right amount of oil and petrol, the engine won’t have the necessary lubrication to run.
So, read the manufacturer’s manual to learn the correct fuel mixture ratio because different brands require different combinations. If you use an electric chainsaw, that’s more reason to keep your engine lubricated.
What Causes Chainsaw Cylinder Aluminum Transfer?
Okay, now let’s talk about the other culprit behind piston scoring. Aluminum transfer happens when the chainsaw is in use. Over time the moving piston causes the buildup of heat and friction, leading to small metal pieces wearing off the piston and transferring to the cylinder wall.
While a little aluminum is acceptable, an excessive transfer can cause problems. The transferred aluminum will cause hot spots on the piston, leading to scoring on the piston or the cylinder wall. This can also cause the piston to seize up in the cylinder, which is a serious issue.
Next are the million-dollar questions – What are a scored piston’s symptoms, and how much piston scoring is acceptable? Find out their answers below.
What are a Scored Piston’s Symptoms?
Let’s look at the common symptoms you might experience if your cutting machine’s piston is scored:
Poor Performance and Difficulty in Startup
First and foremost, you might notice that your chainsaw is performing weakly. This can be due to the reduced compression caused by the scored piston. When the piston is not able to move smoothly, it can create gaps, allowing pressure to escape.
This can, in turn, lead to poor performance of the cutting tool. In addition, reduced compression will also make it for the engine to fire up. So, you may notice that your chainsaw is not kicking up as quickly as it used to before.
Another symptom of a grooved piston is increased vibration. The scoring can cause an increase in friction in the piston movements, leading to increased vibration and more wear and tear on the cutting machine.
A scratched piston will also create a distinct rattling or knocking sound while operating the chainsaw. This can be due to the contact between the scored piston and the cylinder wall.
How much Piston Scoring is Acceptable?
If you are wondering will a chainsaw run with a scored piston and how scoring is acceptable, here’s your answer:
In some cases, a chainsaw with a scored piston can still run, but it will lack optimal performance. This means your tool will struggle to cut through wood, take longer to complete a task, and consume more fuel and electricity than usual.
But in many cases, a grooved piston will cause your machine to stop altogether. Even if your chainsaw is able to run with a scored piston, it’s not a situation that you should ignore. This will cause more wear and tear on your cutting tool, leading to costly repairs in the future.
Now coming to how much scoring is acceptable, well, it depends on its severity and location. If it’s minimal and located on the other side of the exhaust port, it won’t affect your chainsaw’s performance. You can adjust the carburetor and apply the lubrication, which will be sufficient.
But if the scoring is severe and located on the exhaust port, it will significantly impact your machine’s performance. If that happens, you better replace the piston.
What grit to hone a chainsaw cylinder?
The grit to hone a chainsaw cylinder depends on its condition or severity of damage and the manufacturer’s recommendation.
What is the proper way to hone a cylinder?
The proper way to hone a cutting tool cylinder is by using a tool whose size matches the cylinder’s diameter. Then proceed with rotating it back and forth across the cylinder but be careful not to remove too much material.
Can you hone out cylinder scratches?
Honing will only remove minor scratches from the chainsaw cylinder. So, you may need re-boring to remove severely etched grooves.
Do you hone cylinders wet and dry?
Honing can be done wet or dry. Wet honing uses a honing oil to remove debris and reduce heat build-up during the honing process. Whereas dry honing does not involve any lubricant. Ultimately, the choice will depend on the cylinder type and the manufacturer’s recommendation.
Does honing increase bore size?
Yes, honing can increase the bore size, but the increase is negligible and doesn’t concern the engine’s overall performance.
What is the best lubricant to use when honing a cylinder?
When honing a cylinder, the best lubricant to use is a honing oil which reduces heat build-up and helps remove debris during the process. But make sure to get a quality lubricant.
Learning how to hone a chainsaw cylinder and piston requires you to be meticulous. You can remove aluminum buildup and scratches from the cylinder with the right honing technique, suitable tools, and safety precautions. Additionally, you can clear the scoring on the piston and restore its actual seal and compression.
But remember to inspect and clean the cylinder and use an appropriate honing oil to achieve the best results. With patience and detail, honing a chainsaw cylinder and piston can be a cost-effective way of keeping your machine running smoothly.
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