Disassembling the Husqvarna 345 chainsaw: a step-by-step guide for DIY repairs

Chainsaw Husqvarna 345 is a popular semi-professional model known for its reliability and performance. However, even the best quality tools require maintenance. Disassembly may be necessary in several cases: for replacement of worn parts (for example, piston group or bearings), carburetor cleaning after a long period of inactivity, or troubleshooting after a fall or overheating.

Many owners are afraid to disassemble the saw themselves for fear of damaging the mechanisms or losing small parts. In fact, with the right approach and a minimum set of tools (T27 screwdriver, spark plug wrench 19 mm, piston stopper) disassembly Husqvarna 345 no more difficult than changing the oil in a car. The main thing is to follow a clear sequence and remember critical moments, where an error can lead to serious damage.

In this article we will analyze the disassembly process step by step: from removing the side cover to removing the crankshaft. We will pay special attention typical beginner mistakes and give advice on how to avoid them. If you have never held a chainsaw in your hands, it is better to entrust the repair to a specialist. If you have experience working with equipment, this guide will help you save on a service center.

Preparing for Disassembly: Tools and Safety Precautions

Before you begin disassembly, prepare your work area and tools. You will need:

• 🔧 Screwdriver T27 (for housing screws)
• 🔧 Candle key 19 mm (to remove the spark plug)
• 🔧 Piston stopper (can be made from an old spark plug)
• 🔧 Clutch puller (or universal puller)
• 🔧 Flathead screwdriver (for removing circlips)
• 🧴 Solvent or kerosene (for cleaning parts)
• 📦 Containers for small parts (screws, springs, washers)

Important: never disassemble the saw while hanging. Place it on a flat surface, preferably on a soft substrate (for example, a rubber mat), so as not to scratch the case. Also disconnect the spark plug wire and drain the fuel from the tank - this will protect against accidental ignition.

⚠️ Attention: If the saw has recently been used, allow it to cool for at least 30 minutes. A hot engine may warp plastic parts during disassembly.

For convenience, take photographs of the original position of all parts before removal. This will help you put the saw back together correctly. If you parse Husqvarna 345 for the first time, we recommend watching video instructions from an official service center - this will reduce the risk of errors.

Removing the side cover and saw set

Begin disassembly by removing the saw attachment. This is the simplest stage, but there are nuances here:

1. Loosen the bar nut using a combination wrench (usually included with the saw).
2. Remove the chain brake cover by pulling it up and slightly towards you.
3. Carefully remove the bar and chain, being careful not to lose the guide pins.

Under the cover you will see drive sprocket and clutch mechanism. At this stage, you can assess their condition: if the sprocket teeth are heavily worn or the clutch is slipping, the parts will need to be replaced.

⚠️ Attention: Do not use excessive force when loosening the tire nut. If it does not budge, spray the threads with WD-40 and wait 5-10 minutes.

After removing the headset, clean the area under the cover from sawdust and dirt. Use compressed air or a soft brush - do not use metal brushesso as not to damage the seals.

Disassembling the starter and top cover

Starter Husqvarna 345 It is attached to the top cover of the case with four screws. To remove it:

1. Unscrew the screws T27 around the perimeter of the lid.
2. Carefully pry off the cover with a flat-head screwdriver (it may be tight due to the rubber seals).
3. Remove the starter mechanism by pulling it up. Be careful - there is a powerful spring inside!

Pay special attention return spring. If it is deformed or has lost its elasticity, the starter will jerk or not return to its original position. In this case, the spring must be replaced.

After removing the starter, inspect ignition contact group. If there is carbon deposits or corrosion on it, clean it with alcohol. Also check wiring - often rubbing of the insulation leads to short circuits.

Removing the carburetor and fuel pump

Carburetor Husqvarna 345 - one of the most vulnerable nodes. Its disassembly requires care, as there are many small parts inside. Procedure:

1. Disconnect the fuel hose from the carburetor (clamp it with your finger to prevent gasoline from leaking out).
2. Remove the two screws securing the carburetor to the cylinder.
3. Carefully remove the carburetor, do not pull the throttle lever!
4. Disconnect the throttle control rod from the lever.

Below the carburetor is fuel pump (membrane). If the saw has difficulty starting or stalls at idle, the reason may be rupture of the pump membrane or clogged filter mesh. To check the pump:

• 🔍 Remove the top cover of the pump (unscrew 1 screw).
• 🔍 Inspect the membrane for integrity.
• 🔍 Wash the mesh in solvent.

If the membrane is torn, replace it (part no. 503 44 14-01). Also check needle valve - it should move freely without jamming.

⚠️ Attention: Do not use metal objects to clean carburetor jets! Only compressed air or special plastic needles.

After cleaning the carburetor, be sure to blow out all channels and check the tightness of the connections. Air leakage through the gaskets will cause the engine to not operate properly.

Removing the clutch and drive sprocket

Clutch Husqvarna 345 - centrifugal type. To remove it you will need piston stopper and a puller. Sequence of work:

1. Remove the spark plug and insert a piston stopper (or rope) into the cylinder.
2. Screw the puller onto the clutch and secure it with a key.
3. Remove the clutch with a sharp counterclockwise movement.

Under the clutch is drive sprocket. It can be solid or collapsible. If the sprocket teeth have pointed shape or visible chips, it must be replaced (item number 503 38 13-01).

Pay special attention needle bearing under the star. If it plays or makes a creaking noise, replace it along with the sprocket. The bearing cannot be replaced separately!

After removing the clutch, inspect drum for the presence of cracks. If there are any, the drum must be replaced, since during operation it may shatter into fragments.

Engine disassembly: piston group and crankshaft

This is the most difficult stage and requires experience. If you are not confident in your abilities, it is better to stop at the previous steps and take the saw to a service center. To disassemble the engine:

1. Remove the muffler (unscrew the 2 screws).
2. Remove the 4 screws securing the cylinder to the crankcase.
3. Carefully remove the cylinder by prying it around the perimeter with a screwdriver.
4. Remove the piston along with the connecting rod.

Inspect piston and cylinder:

• 🔍 Seizures on the piston skirt - a sign of overheating or lack of oil.
• 🔍 Scratches on the cylinder walls - require honing or liner replacement.
• 🔍 Piston play in the cylinder — wear of the piston rings or cylinder.

If the piston has deep grooves, it needs to be replaced (part number 503 64 21-01). The same goes for rings - if they have lost their elasticity or have gaps of more than 0.5 mm, replacement is required.

Crankshaft Husqvarna 345 usually lasts a long time, but its bearings can wear out. Check the shaft play - if there is any, the bearings must be replaced. This will require special puller and press.

⚠️ Attention: When assembling the engine, be sure to lubricate the piston and rings with engine oil. Dry assembly will lead to scuffing when first started!

After replacing the piston group, be sure to run the saw in Idle for 10-15 minutes, then let it cool and check the compression.

Chainsaw assembly: order and nuances

Assembly Husqvarna 345 is carried out in the reverse order, but there are several critical points:

1. Install the piston in top dead center (TDC) before installing the cylinder.
2. Tighten the cylinder mounting screws criss-crossto avoid skew.
3. When installing the clutch, use torque wrench (tightening torque: 30–35 Nm).
4. Before installing the carburetor, check tightness of gaskets.

After assembly:

• 🔧 Fill with fresh fuel (a mixture of gasoline and oil in the proportion 50:1).
• 🔧 Check the work chain brake.
• 🔧 Start the saw and let it idle for 2-3 minutes.

If the saw does not start after assembly, check:

• 🔋 Presence of a spark on the candle.
• 🔋 Fuel entering the carburetor.
• 🔋 Correct installation of the ignition (the gap between the coil and the flywheel should be 0.2–0.3 mm).

FAQ: Frequently asked questions about disassembly Husqvarna 345