How to Mix Chainsaw Fuel

Two stroke engines require an oil and fuel mixture for the engine to run properly. The reason for this is that most two stroke engines don't have separate lubrication systems, so the fuel has to also provide lubrication to the moving parts of the engine.

One of the reasons that two stroke engines produce more smoke than four stroke engines is because of this—the engine is burning oil as well as fuel. Most modern two stroke engines suggest a 50:1 gasoline-to-oil ratio to power the engine. Some chainsaw operators feel more comfortable using extra oil in their mixtures because it provides additional lubrication, but this could also cause heavier smoke than normal. In any case, you should check your owner’s manual for the recommended ratio, or if you have an old chainsaw, mix a higher ratio such as 40:1 or 30:1 just to be on the safe side.

Here is the process:

1. Get two stroke engine oil, such as Lucas Two Cycle Oil, and unleaded, 89 octane (or higher) gasoline. It's important to use two-stroke engine oil only because it is specially formulated for two-stroke engines to prevent build up in the engine.
2. Measure out your ratio according to the recommended amount. This calculator is a handy way to figure out the exact measurement of oil in ounces you need for the corresponding amount of gas in gallons. The corresponding measurements for 50:1 are 2.6 ounces of oil for every gallon of gas.
3. To mix the solution effectively, you can add half the amount of gas and the full amount of oil to a gas container and shake the container. Add the rest of the gas and shake again. Don't try to mix the oil and gas in the fuel tank of your chainsaw, as it will be difficult to get the measurements right. You will also want to mix more than will fit in your chainsaw's gas tank so you have some extra on hand for refueling later.
4. As an optional step, you can add a fuel enzyme treatment that will stabilize your fuel and ensure that your gasoline stays good for up to 2 years. Many gasolines now contain ethanol, and enzyme treatment will help to stabilize your fuel and prevent problems that arise from ethanol containing fuel.
5. Now it’s time to fill up your fuel tank. There are a few things to remember when fueling your chainsaw:
• Always wipe up any excess spillage on your chainsaw.
• Start your machine at least 10 feet away from where you refueled.
• Always start your chainsaw in a very well-ventilated area.

If you have various cans of gasoline, it doesn't hurt to label the can you just mixed with the ratio to help you remember what mixture you made in that can. You should also always shake the container before refueling your chainsaw because the oil and gas will become separated after the mixture settles.

And if you suspect you need any new parts for your chainsaw to get it up and running, don't hesitate to contact us or visit our store to get everything you need.

How to Break in a Small Engine

When you get a new chainsaw, cut off saw, lawn mower, or other small engine powered piece of equipment, it's critical to break the engine in so it runs properly. The reason behind this is that you want to heat the engine up to seal the piston rings to the cylinder wall, which will minimize friction in the cylinder and prevent oil from gathering in the cylinder wall. For this reason, it's also important to break in your engine again if you replace the piston rings.

So how do you break a small engine in exactly?

1. Fill the engine with the recommended oil

Your owner's manual will specify what type of oil to put in your power equipment. Be sure to regularly change your oil and make sure that there is enough in the engine at all times. For two-stroke engines, we recommend using Lucas 2-Cycle Semi-Synthetic Oil. Lucas oil is formulated with a blend of mineral oil, synthetic oil, and low ash additives that allows fuel to burn thoroughly for smoother engine operation.

2. Idle the saw for 5 minutes

Start up your engine like normal and let it run idle for a few minutes to get the engine warmed up. You can rev the engine a bit to keep it from shutting down, but you want to make sure the engine is warmed up before running it normally.

3. Run the engine as normal, but not at full throttle

For at least 5 hours, you will want to run your engine as normal but don't hit full throttle just yet. If you do run your engine at full throttle, you risk deformation of the cylinder bores. After this period, it's okay to run the engine at full throttle when it has a load. Many chainsaw operators recommend only running the saw at full throttle when the saw is in the cut, for example.

4. Change the oil

Some chainsaw operators and technicians recommend changing the oil in a new saw after an hour of operation. Most new saw owner's manuals will tell you to change the oil after 5 hours of operation. If you want to be extra safe, you can do both, but generally speaking, changing your oil after 5 hours is sufficient. The reason for this oil change is to remove any tiny debris that has broken away from the engine components and remained trapped in the oil.

Once the saws oil has been changed after the 5 hour threshold, your saw is ready to use regularly and at full throttle. Many technicians and small engine experts have their own methods of breaking in their engines. Please leave your comments with your own method!

HLSupply provides small engine parts for chainsaws, mowers, cut off saws, and more. Visit our store for our complete selection of parts including cylinders & piston rings.

Understanding Your Power Tools: How Do Two Stroke Engines Work?

Understanding how your small engine works is critical to keeping it properly maintained and in working order. Two stroke engines can be especially susceptible to malfunctions, and learning about how they work will help you understand why.

Two stroke engines are internal combustion engines. This means the combustion of fuel occurs in a chamber (in our case, a cylinder) to create force to another part of the engine (a piston). There are 5 steps that are a part of all combustion engines.

1. Intake: When both air and fuel enter the engine. In the case of a power tool, this would be oxygen and the mixture of gasoline and two-stroke engine oil that you use to fuel your power equipment.

2. Compression: When the air and fuel are compressed into a small volume. In a small engine, the piston forces the fuel and air into the cylinder creating compression.

3. Ignition: When the air and fuel are burned. This occurs by the spark plug creating a spark and igniting the fuel and oxygen.

4. Power: The ignition creates energy, and therefore, power. This pushes the piston back down, allowing it to turn the crankshaft and begins to repeat the process.

5. Exhaust: The leftover gas from the ignition of the fuel and oxygen mixture exits the engine. The process is then repeated.

Here is an illustration of how this five step process works:

You might be wondering how a two-stroke engine compares to a four-stroke engine as far as gas flow is concerned. In a two-stroke engine, the flow of gas requires a seamless flow pattern to avoid any turbulent mixing of the spent charge (combusted fuel mixture) with the new charge (fresh fuel mixture). Scavenging is critical in a two stroke engine to ensure that a fresh fuel and air mixture is used in the next cycle, as defined in the 5 step process above.

Scavenging is an essential part of having a properly running engine. When this function isn’t performed properly, exhaust fumes will combine with the fresh mixture, diluting the fresh air and gas of its combustibility and causing a poorly running engine.

The reason that this information is important for operators of two-stroke engines is because proper scavenging is more difficult to achieve in a two-stroke engine making them more prone to problems. Understanding the process will help you diagnose engine issues more easily and allow you to properly install your small engine parts.

Contact us if you have any questions about installing your new small engine replacement parts from HLSProParts.com and we will be happy to help where we can!