What Is The Difference Between Stihl 045 Models (Chainsaw Specs)

The STIHL 045 and 045 AV are approximately 76.5 cm³ saws; the AV adds an anti-vibration system, not necessarily a chain brake. The 045 AV Super is the larger model, at about 87 cm³. Bar, chain, ignition, and safety equipment can vary, so identify the exact saw and check its serial-specific manual and parts information before choosing parts or operating it.

If you have found an old 045 in a shed, inherited one, or seen its name in a manual, the model badge can be a useful start—but it does not answer every setup question. A few letters mark an important engine difference, while other details depend on the saw’s production version and the parts fitted to it.

I approach vintage-saw comparisons by separating what the model name tells you from what needs to be checked on the actual saw. That helps prevent a common mistake: ordering a bar or chain based on “045” alone, or assuming that “AV” means a chain brake is present.

What Is the Difference Between STIHL 045 Models?

The main difference is engine size and equipment. The 045 and 045 AV are about 76.5 cm³, while the 045 AV Super is about 87 cm³. “AV” identifies anti-vibration equipment. It does not, on its own, confirm a chain brake, bar setup, or other feature on a particular saw.

Displacement is the volume swept by the engine’s piston. It is one measure of engine size, not a guarantee of cutting speed or condition. Two old saws with the same model name can perform very differently if one has worn parts, a damaged cylinder, or an incorrect carburetor setup.

The 045 AV Super is not simply an ordinary 045 with vibration control added. Its larger displacement is a key distinction. The 045 and 045 AV, by contrast, share the approximate displacement shown above; the AV name points to vibration-reducing equipment.

The model name alone does not establish horsepower, weight, bar length, chain pitch, or chain-brake equipment. Those details can depend on the exact version, fitted parts, and documentation. Treat commonly repeated figures online as a lead to verify, not as a safe parts order.

Identify the 045 Variant, Bar Setup, and Safety Equipment

Start with the model marking and serial number, then verify the saw against the correct operator’s manual and parts information. This matters because old saws may have replacement bars, sprockets, ignition parts, or safety equipment. A correct model identification is the first step, not proof that every fitted part is original.

Look for the model designation on the saw’s identification markings. Record the serial number too. Use both when checking a manual, parts list, or with a STIHL dealer familiar with older equipment. If markings are worn or missing, do not identify the saw by appearance alone; have a qualified repair shop confirm it.

Confirm the bar and chain as a set

A chain pitch is the spacing of the chain’s drive links, and gauge is the thickness of the drive link that fits into the bar groove. The bar mount must also fit the saw. These details, along with drive-link count, have to match the bar, chain, and drive sprocket.

Check the bar stamp for its specifications and inspect the sprocket for its markings or type. Then confirm that the chain matches both. Do not choose a chain by model name, bar length alone, or a seller’s broad “fits 045” description. If markings are unclear, take the bar, chain, and sprocket details to a parts professional.

Check safety equipment, not just the badge

“AV” refers to anti-vibration features that reduce vibration reaching the handles. It does not mean “automatic brake,” and it does not confirm that the saw has a chain brake. Check the saw itself and its correct manual to determine whether a brake is fitted and how it should be tested.

Before use, inspect the throttle lockout, chain catcher, handles, controls, chain tension, bar, and oiling system. If a chain brake is fitted, confirm its condition and function according to the manual. Do not operate a saw with a damaged control, missing safety part, or uncertain brake function.

A useful identification record includes:

• Model marking and serial number
• Bar stamp, including pitch and gauge if shown
• Chain pitch and drive-link count
• Sprocket type or markings
• Whether a chain brake is fitted and working
• Any visible replacement parts or modifications

Start and Operate the Saw for Field Cutting

The starting procedure and safe operating steps depend on the exact saw and its condition. Use the instructions for that model, keep the chain clear of people and objects, and make sure the saw is stable before starting. If its controls or safety equipment are unfamiliar, pause and get help before running it.

Use the manual’s cold-start or warm-start procedure. Start on stable ground, with the chain clear, and engage the brake as directed if that saw has one. Once running, check that the chain stays still at idle and that the oiler supplies bar-and-chain oil. If the chain moves at idle or oil delivery is uncertain, stop and investigate before cutting.

Rotational kickback can happen when the upper nose of the bar touches wood or another object. The chain can drive the saw sharply upward and toward the operator. Keep the bar nose clear, hold the saw with both hands, and do not count on a chain brake unless that particular saw has one and it has been inspected.

Wear chainsaw-rated leg protection, suitable boots, gloves, hearing protection, and a helmet with face and eye protection. Before cutting, assess the tree or log, its lean and tension, overhead hazards, footing, and escape route. Keep others outside the work area. Use a qualified tree worker for hazardous trees or work above ground.

A larger engine does not make a saw a better choice for every job. The 045 AV Super’s larger displacement is a specification difference, not a reason to use a longer bar or take on work beyond your skill. Select the setup for the saw’s verified parts and the work at hand.

Maintain, Sharpen, and Tune the 045

Maintenance specifications cannot safely be taken from the model name alone. Use the correct manual and chain maker’s instructions for fuel mix, carburetor settings, sharpening, and depth gauges. If the saw lacks clear documentation or has unknown modifications, ask a qualified technician to identify its setup before tuning or cutting.

Fuel and carburetor settings

Use the fuel-to-oil ratio and oil type specified for the exact saw and oil in use. Do not apply a modern STIHL ratio or engine-speed limit to a vintage 045 without checking its manual. Carburetor settings and idle or maximum-speed limits also need to come from the right documentation or a qualified technician.

An engine set too lean can overheat and seize. Avoid turning carburetor screws by guesswork, especially if you cannot verify the correct baseline or safely measure engine speed. If the saw will not idle correctly, runs poorly, or has an unknown carburetor, have it inspected before use.

Chain sharpening and lubrication

Use the chain manufacturer’s specified file diameter and depth-gauge setting. A depth gauge, sometimes called a raker, controls how much wood each cutter takes. Its correct height depends on the chain, so the model name does not provide a safe setting.

Use bar-and-chain oil and verify that oil reaches the chain as the manual directs. Do not guess at a flow setting or assume that oil is moving because the reservoir is full. Stop if lubrication is not confirmed; running a chain without proper oil can damage the chain and bar.

A practical identification example

Suppose one saw is marked 045 AV and another is marked 045 AV Super. The first step is to record each serial number and confirm the engine version through the right parts information. Next, inspect each bar stamp and sprocket rather than assuming their cutting setups match. This small check can prevent ordering a chain that fits neither saw.

If a third saw has no readable badge but appears similar, its look is not enough to establish that it is an 045 AV or Super. Record any remaining serial or part markings and ask a qualified shop to identify it. Do not set fuel, carburetor, or chain specifications from a visual guess.

Store and Prepare the Saw for Seasonal Use

Storage does not change the model’s specifications, but it can reveal problems before the next job. Shut the saw down, let it cool, and follow its manual for fuel, chain tension, and storage steps. On a vintage saw with uncertain service history, inspect it before restarting rather than assuming it is ready.

After use, stop the engine and allow it to cool. Clean the cooling fins and air filter as directed, and inspect the bar, chain, sprocket, and oil passages. Handle chain tension only as the manual instructs. Refuel outdoors after the engine has cooled, away from ignition sources.

Before seasonal use, recheck the model and serial details if you have not already done so. Confirm the chain is sharp, correctly matched, and not loose or damaged. Verify oil delivery and safety controls before cutting. If the saw has been stored with fuel or has unknown modifications, a service inspection is a sensible first step.

Frequently Asked Questions

Is the STIHL 045 AV more powerful than the standard 045?
Both are approximately 76.5 cm³. AV identifies anti-vibration equipment; it does not indicate a larger engine.

How much displacement does an 045 AV Super have?
The 045 AV Super is approximately 87 cm³, compared with about 76.5 cm³ for the 045 and 045 AV.

Does every STIHL 045 AV have a chain brake?
No. AV means anti-vibration, not chain brake. Check the specific saw and its manual.

Is the 045 AV Super just an 045 AV with vibration control?
No. It is the larger-displacement version, at about 87 cm³. The AV marking alone does not explain all equipment differences.

Can I use the same bar on every 045 model?
Do not assume so. Confirm the bar mount, pitch, gauge, sprocket, and chain drive-link count for the actual saw.

How do I find the right chain for an 045?
Read the bar and chain markings, inspect the sprocket, and confirm that all parts match using the correct parts information. Do not order by model name alone.

What fuel mix should I use in a vintage STIHL 045?
Use the ratio specified for that exact saw and oil. Do not substitute a modern STIHL recommendation without checking the vintage saw’s manual.

Can I tune the carburetor by ear?
That is not a safe substitute for the specified settings and engine-speed limits. Incorrect lean tuning can damage the engine; consult the manual or a qualified technician.

Why does the chain move while the saw idles?
Stop the saw and investigate. Do not cut until the idle is corrected and the chain remains stationary, as the manual requires.

What should I check before using a stored 045?
Inspect controls, chain, bar, sprocket, chain tension, and oil delivery. Confirm fitted safety equipment and use the manual’s starting procedure before cutting.

(This article was written by one of our staff writers, Evan Bradley. Visit our Meet the Team page.)