Husqvarna 135 Mark II Issues (Troubleshooting)
The Husqvarna 135 Mark II is a 38 cm³ occasional-use saw, and most no-start problems come down to fuel, spark, or compression. Start with fresh 50:1 fuel, the correct switch and choke settings, and a clean air filter. Then check the spark plug and engine condition. Don’t buy parts or adjust carburetor screws until tests point to a cause.
A well-kept 135 Mark II can handle routine ground-level cutting, but durability does not make it immune to stale fuel, a flooded engine, a dirty filter, or wear. If you have pulled the cord again and again, stop for a few minutes. A step-by-step check is safer and often cheaper than replacing parts at random.
Equipment Setup and Safety Preparation
Before troubleshooting or starting, make the saw safe to inspect. The chain can move unexpectedly, and fuel vapors can catch fire. Work outdoors, keep the saw away from flames and sparks, and place it on firm ground. Wear eye protection and gloves; use the protective gear required for any cutting.
The 135 Mark II is rated at 38 cm³ and a maximum power of 1.6 kW at 9,000 rpm. For occasional ground-level work, use only a bar-and-chain setup approved for your exact saw. A 14- to 16-inch bar is common, but check the saw manual and bar markings before fitting parts.
Before attempting a start, check:
- Chain brake, throttle lockout, chain catcher, handles, and fasteners for damage or loose parts.
- Bar, chain, and sprocket area for debris, damage, or a chain that is too loose.
- Fuel and bar-oil caps for leaks or damage.
- The air inlet and filter for heavy sawdust or dirt.
Do not operate the saw if fuel is leaking, a safety part is damaged, or the chain moves while the engine idles. Keep bystanders clear. If you are unsure how to check a safety feature, stop and have the saw inspected rather than bypassing it.
Quick No-Start Diagnosis
A no-start diagnosis separates a fuel problem from a spark or engine problem. Change one thing at a time and note what you find. This prevents a common mistake: replacing a plug or carburetor before confirming that the saw has fresh fuel, the right starting settings, and a clear air path.
1. Confirm the starting procedure
Use the cold- or warm-start procedure in the Husqvarna manual for your saw. Set the on/off switch correctly, engage the chain brake for starting, and place the saw on firm ground. If the engine has been running recently, use the warm-start procedure rather than treating it as cold.
If the engine briefly fires and then stops, the choke setting may need to change as directed in the manual. Repeated pulls with the choke left on can flood the engine. If the saw smells strongly of fuel, pause and follow the manual’s flooded-engine procedure instead of continuing to pull.
2. Check fuel and air
The specified mix is 50:1, or 2%, using quality oil made for air-cooled two-stroke engines. Use fresh fuel and follow the manual’s fuel-octane and ethanol limits. Old or incorrectly mixed fuel can cause hard starting and poor running. Do not use straight gasoline or guess at the oil ratio; either can cause rapid engine damage.
Remove and inspect the air filter as the manual directs. If it is dirty, clean or replace it using the recommended method. A blocked filter limits airflow, but running without the filter can let abrasive dirt enter the engine.
3. Inspect the spark plug
Let the saw cool, then remove the plug as described in the manual. A wet plug can point to flooding or fuel reaching the cylinder without ignition. A dry plug after repeated start attempts can point to a fuel-delivery problem, though it does not prove which part has failed. Check for visible damage and use the specified plug type and gap.
For an ignition check, use a suitable inline spark tester and follow its instructions. Test outdoors, away from spilled fuel or vapor. Do not hold a plug by hand to check for spark. No spark may involve the plug, ignition lead, stop-switch circuit, or ignition module; further testing should follow the service manual.
4. Consider compression if fuel and spark checks pass
Compression is the pressure the engine builds inside the cylinder. If correct fuel, a clean air filter, and a confirmed spark do not explain the no-start, a compression test or internal inspection may be needed. I avoid naming a pass/fail pressure without the service specification for the exact model and test method.
| What you find | What it may indicate | Next check |
|---|---|---|
| Plug is wet after repeated pulls | Flooding or failure to ignite fuel | Use the manual’s clearing procedure; test spark safely |
| Plug stays dry | Fuel may not be reaching the cylinder | Confirm fresh mix and correct start procedure; seek fuel-system testing |
| No spark on an inline tester | Ignition or stop-switch circuit fault | Follow the model’s electrical test procedure |
| Fuel, air, and spark checks do not solve it | Possible compression or internal engine fault | Arrange a proper compression and engine inspection |
A single clue is not a diagnosis. For example, a wet plug does not prove the carburetor is faulty, and a dry plug does not prove the fuel line is blocked. Record the result of each check before moving on.
Field Cutting and Landscaping Operation
Once the saw starts and runs properly, cut only within your training and the saw’s intended use. The 135 Mark II is suited to occasional ground-level cutting, not commercial production. Keep both hands on the handles, maintain a stable stance, and cut below shoulder height. Release the chain brake only when you are ready to cut.
The bar nose is the curved tip of the guide bar. If its upper area contacts wood or another object, rotational kickback can throw the bar up and back quickly. Keep the nose clear and do not cut with the bar tip. A chain brake reduces risk but cannot prevent every injury.
Stop cutting if the kerf closes, the bar pinches, the saw binds, or the chain derails. Do not force a dull chain through wood. Check tension and sharpen the chain to the chain maker’s specified angles and depth-gauge setting.
Troubleshooting examples: If the engine starts but bogs in a cut, first check for a dull or poorly tensioned chain and a dirty air filter. If it idles but the chain moves, stop using the saw. The idle speed is 3,000 rpm; have the idle, carburetor, and clutch checked rather than turning mixture screws at random.
Maintenance, Sharpening, and Troubleshooting
Routine care helps prevent repeat starting and cutting problems. After the engine is off and cool, clean the cooling-air inlet, cover, bar groove, and sprocket area. Check chain tension, bar condition, and oil delivery. The saw has automatic lubrication, but you still need to confirm oil reaches the bar.
Use dedicated chainsaw bar-and-chain oil. Do not assume one oil viscosity or delivery rate suits every temperature and setup; follow the manual and check that the chain is receiving oil. Match replacement parts carefully: common fitments use 3/8-inch mini pitch and .050-inch (1.3 mm) gauge, but drive-link count depends on the exact bar. Read the bar stamp and chain package before buying.
A useful repair sequence is to write down the symptom, test, and result. For example: “No start; fresh fuel confirmed; filter clean; plug wet; spark tester shows spark.” That record helps narrow the next test and prevents buying the same guess twice. Persistent bogging, poor idle, hard starting, or excessive vibration calls for inspection, not repeated operation.
Storage and Seasonal Care
Fuel can deteriorate during storage, so follow the manual’s instructions for the fuel system and storage period. Before putting the saw away, switch it off, let it cool, clean debris from the cover and bar area, and inspect the chain and bar. Store it in a dry, secure place away from children and ignition sources.
At the next use, check the saw again rather than assuming it is ready because it ran well last season. Confirm fresh, correctly mixed fuel, sound safety parts, proper chain tension, and bar-oil flow. If it still will not start, return to the fuel-spark-compression checks instead of adjusting the carburetor by trial and error.
Frequently Asked Questions
Why won’t my Husqvarna 135 Mark II start after many pulls?
Check the manual’s start procedure, fuel freshness and mix, air filter, and spark plug condition. If the plug is wet, the engine may be flooded. If these checks do not identify the problem, test spark safely and have compression checked to the correct service specification.
What fuel mix does the 135 Mark II use?
Use a 50:1 mix, equal to 2% quality oil made for air-cooled two-stroke engines. Follow the manual’s fuel-octane and ethanol limits, and use fresh fuel. Never use straight gasoline or an unverified mix.
What does a wet spark plug mean?
A wet plug means fuel is present on the plug, often after repeated choke-start attempts. It may indicate a flooded engine or a failure to ignite the mixture; it does not by itself identify a faulty carburetor. Follow the manual’s flooded-engine procedure.
What if the spark plug is dry?
A dry plug can mean fuel is not reaching the cylinder, but it is not proof of a specific failed part. Recheck the starting procedure and fuel, then use the service manual for fuel-system diagnosis. Do not replace the carburetor based on this clue alone.
What should the idle speed be?
The specified idle speed is 3,000 rpm. If the chain moves while the saw idles, stop using it and have the idle, carburetor, and clutch checked. Do not try to solve it by arbitrarily turning mixture screws.
Which bar and chain fit this saw?
Use only a combination approved for the exact saw. Common setups use 3/8-inch mini pitch and .050-inch (1.3 mm) gauge, but the correct drive-link count depends on the bar model. Check the bar stamp, chain packaging, and manual before fitting a chain.
Why does the saw bog down while cutting?
Check for a dull chain, incorrect tension, a dirty air filter, or a bar that is binding. If those checks do not explain recurring bogging, stop and arrange a fuel-system or engine inspection. Do not force the saw through the cut.
Is it safe to keep cutting if the chain moves at idle?
No. Stop using the saw. A chain moving at idle can create an injury risk and may point to an idle-setting or clutch problem. Have those parts checked before operating again.
How do I check that the chain is getting oil?
Follow the manual’s oil-flow check and keep clear of the moving chain. Use dedicated bar-and-chain oil, and inspect the bar groove and oil passage for debris. If flow remains uncertain, have the lubrication system checked before cutting.
(This article was written by one of our staff writers, Robert Callahan. Visit our Meet the Team page.)
