Husqvarna 42 Special Setup (Starting Guide)
A safe setup for a Husqvarna 42 Special starts with checking the saw’s own manual and fitted parts, not assuming every version has the same specifications. Confirm the bar and chain match, use only the specified fuel mix, inspect safety controls, and follow the correct cold- or warm-start procedure. Stop if the chain moves at idle or any safety part fails.
A used 42 Special can look ready to work while hiding a mismatched bar, worn chain, or fuel mix that does not suit its manual. I would treat setup as a series of checks, not a quick pull on the starter rope. The model is a legacy saw of roughly 42 cc, but its age and replacement parts make verification especially important.
This guide covers ground-level firewood and landscape cutting on a serviceable saw. It does not teach tree felling, climbing, or repairs that call for specialist tools. If you cannot verify a part or setting, pause and get help from a qualified chainsaw dealer.
Identify the fitted bar and chain
The 42 Special’s bar setup cannot be confirmed from the model name alone. Replacement bars and chains may differ between saws, so read the markings on the parts actually fitted and compare them with the saw’s manual or parts information before buying or cutting.
A 13–16 inch bar is a practical general-purpose range for a saw in this class, but length does not prove that a bar fits. Bar mount, chain pitch, gauge, and drive-link count all matter.
- Pitch is the size of the chain links and sprocket system. Many setups use standard 3/8-inch pitch, but check your saw and parts.
- Gauge is the thickness of the chain’s drive links, which sit in the bar groove.
- Drive-link count is the number of links that travel around the bar.
Read the bar stamp for its pitch, gauge, and link count, then confirm that the chain and sprocket are compatible. Do not confuse standard 3/8-inch chain with 3/8-inch low-profile chain. They are different systems and should not be mixed.
| Check | What to verify | If it does not match |
|---|---|---|
| Bar mount | The bar fits the saw’s mounting pattern | Do not force it or modify parts |
| Pitch | Bar, chain, and sprocket use the same pitch | Replace with a confirmed compatible set |
| Gauge | Chain drive links match the bar groove | Do not run a loose or binding chain |
| Drive-link count | Chain length matches the bar | Use the count specified for that bar |
| Bar length | Length suits the saw and intended work | Confirm in the manual before use |
Next step: If the stamp is missing or unreadable, take the bar and chain to a dealer for identification. Do not guess from appearance.
Inspect and prepare the saw safely
A preflight check finds faults before the engine is running. Check the controls, cutting parts, and work area every time. Wear a helmet with eye and face protection, hearing protection, chainsaw-rated leg protection, gloves, and sturdy boots; a chain brake reduces risk but does not replace safe handling.
With the engine off, inspect the chain brake, throttle interlock, stop switch, chain catcher, handles, bar, chain, and fasteners. The throttle interlock should prevent throttle operation unless it is pressed as designed. If a control is damaged, a handle is loose, or the brake does not work correctly, do not start the saw.
Set chain tension according to the manual for the saw and bar. The chain must sit in the bar rails, move by hand while wearing gloves, and stay engaged along the underside of the bar. Do not adjust it while the engine is running. Recheck tension after the first run and again after the chain cools.
Fill the oil tank with suitable chainsaw bar-and-chain oil. Before cutting, confirm that the saw is delivering oil using the manual’s check procedure. If oiling seems absent or abnormal, stop and inspect the system rather than continuing to cut.
Choose a stable work area. Keep bystanders away, clear your footing, and plan an escape route from the cutting area. Look for overhead hazards and consider wind, slope, and wood under tension. For tree work, follow ANSI Z133 and applicable OSHA rules; felling and climbing are not beginner tasks.
Next step: Do not proceed until the controls work, the chain fits and moves correctly, and the work area is clear.
Mix fuel and start the engine
Fuel instructions depend on the applicable manual and oil label. Use fresh unleaded gasoline with quality air-cooled two-stroke oil at 50:1 only if the correct Husqvarna manual specifies that ratio. At 50:1, the mix is 20 mL of oil for each 1 L of gasoline. Older manuals or oils may call for another ratio.
Never use straight gasoline in this two-stroke engine, and do not choose a ratio by habit. Wrong fuel can cause severe engine damage. Keep fuel and bar oil in labeled, approved containers, and refuel only after the engine is shut down and cool, away from ignition sources.
For starting, work outdoors on firm ground. Keep the bar clear of people and objects, engage the chain brake, and secure the saw as directed by its manual. Use the manual’s cold-start or warm-start steps; control labels and sequences can vary. In general, use the specified choke setting for a cold engine, pull until it fires, then return the choke to the run position promptly. Leaving the choke on after the engine fires can load it up and make starting harder.
Once running, check that the engine idles steadily and that the chain stops at idle. If the chain moves while the saw is idling, stop the engine and correct the fault before cutting. Do not adjust carburetor screws by guesswork. Use model-specific RPM specifications and a tachometer, or have a qualified technician do the work.
| Condition | Setup action | Stop and investigate if… |
|---|---|---|
| Cold engine | Follow the cold-start steps in the manual | It does not fire as expected; avoid endless pulling |
| Warm engine | Use the warm-start setting, not full choke by default | The engine floods or will not settle to idle |
| Chain at idle | Confirm it remains still before cutting | It creeps or spins |
| Bar oil | Check delivery by the manual’s method | Delivery appears absent or abnormal |
Next step: If the saw will not start, idle steadily, or stop its chain at idle, diagnose it before use rather than changing settings at random.
Make a controlled first cut
A first cut should confirm that the saw runs and oils correctly under light work. Use a firm two-handed grip, keep your footing stable, and cut only within your training and the saw’s capacity. Stop the engine before carrying the saw, clearing a jam, refueling, or adjusting the chain.
Keep the guide-bar nose away from the wood. Contact with the upper part of the bar nose can cause rotational kickback, which may throw the saw toward you. A chain brake is a safety measure, not a guarantee against injury. Do not cut above shoulder height, and do not force a dull chain through wood.
If the chain starts to bind, the saw behaves oddly, or oiling appears to stop, shut it down and reassess. Cutting harder is not a fix for a dull chain, a mismatched setup, or a mechanical problem.
Practical setup scenarios
These are check-based examples, not claims about a particular saw’s history. They show how I would handle common setup questions on a used 42 Special.
Scenario: The bar looks right, but the chain is unknown. I would read the bar stamp, count or verify the chain’s drive links, and check pitch and gauge against the sprocket and manual. If any measurement is uncertain, I would not run it until a dealer confirms the combination.
Scenario: The saw starts, but the chain turns at idle. I would stop the engine and keep the saw out of service. The idle or another fault needs proper diagnosis; I would not try to mask it with an arbitrary carburetor adjustment.
Scenario: The chain cuts slowly and needs pressure. I would stop and inspect cutter sharpness, chain tension, and lubrication. I would sharpen to the chain maker’s file and depth-gauge specifications or have the chain serviced, rather than push harder.
Next step: Use a light first cut only after the setup passes inspection and the engine idles with the chain stopped.
Maintain and store the 42 Special
Routine care helps the saw stay ready, but exact service settings should come from the manual for the saw and fitted components. Clean the air filter and cooling fins as needed, and inspect the spark plug, fuel lines, starter, sprocket, bar groove, and oil passages for wear or blockage.
Sharpen with the file size and angles specified for the installed chain. Keep cutters even, and set depth gauges to that chain maker’s specification. A depth gauge controls how much wood a cutter takes; 0.025 inch is common on some chains but is not a universal setting for every 42 Special chain.
Rotate or dress the bar when appropriate and replace worn parts. If the saw idles poorly, accelerates poorly, or oils abnormally, stop and diagnose it. Air leaks and fuel-system faults should not be “fixed” by turning carburetor screws without the correct model-specific procedure.
For extended storage, follow the manual’s fuel-system instructions. Clean the saw, protect the bar and chain, and store it dry and secure, away from children. Before returning it to service, inspect the controls, chain condition, tension, and oil delivery again.
Next step: Keep the manual with your service notes, including the confirmed bar-and-chain combination and fuel ratio.
Frequently asked questions
These quick answers cover the most common setup decisions. The saw’s own manual and the markings on its fitted parts take priority whenever specifications differ.
What size bar should I use on a Husqvarna 42 Special?
A 13–16 inch bar is a practical general-purpose range, but confirm the mount and approved setup in the manual. Bar length alone does not establish compatibility.
What chain fits a 42 Special?
There is no safe universal answer from the model name alone. Match pitch, gauge, and drive-link count to the bar and sprocket, and confirm the combination with the manual or a dealer.
Does the 42 Special use 3/8-inch chain?
Many configurations use standard 3/8-inch pitch, but verify yours. Do not substitute 3/8-inch low-profile chain for standard 3/8-inch components.
What fuel mix should I use?
Use the ratio specified by the applicable Husqvarna manual and two-stroke oil label. Use 50:1 only when that documentation calls for it; never run straight gasoline.
How tight should the chain be?
Follow the saw and bar instructions. The chain should sit in the rails, move by hand with gloves, and remain engaged under the bar. Recheck after initial running and after cooling.
Why does the chain move at idle?
Treat it as a fault. Stop the engine and do not cut until the cause is corrected. Do not make arbitrary carburetor adjustments.
Can I use 0.025-inch depth gauges?
That setting is common for some chains, not universal. Use the specification for the chain fitted to your saw.
How do I check bar-oil delivery?
Use the method described in the manual. If delivery seems absent or abnormal, stop and inspect the oil system before cutting.
What should I do if the saw will not start?
Recheck the cold- or warm-start procedure, fuel condition and ratio, and basic service condition. If it still will not start, seek model-specific diagnosis rather than changing carburetor settings by guesswork.
Can a beginner use the 42 Special for felling?
This guide is for ground-level cutting. Felling and climbing require training and safe work practices; they are not beginner tasks.
(This article was written by one of our staff writers, Elliott Fowler. Visit our Meet the Team page.)
