Jonsered 455 Chainsaw Manual

The Jonsered 455 is a professional-grade chainsaw designed for demanding forestry and arborist work. It features a powerful 55.5cc engine, X-Torq® technology for reduced emissions and fuel consumption, an air injection system for cleaner air filters, and a robust construction for durability. Below are key sections for safety, features, assembly, operation, maintenance, and troubleshooting.

Features at a Glance

Key components: 55.5cc X-Torq® engine, Air Injection system, Side-mounted chain tensioner, Combined choke/stop control, Inertia activated chain brake, Quick-release air filter, LowVib® anti-vibration system.

Safety Instructions

Read and understand all instructions before use. Always wear appropriate PPE.

1. Personal Protective Equipment (PPE): Always wear safety helmet, hearing protection, eye protection (visor/goggles), protective gloves, chainsaw protective trousers, and sturdy boots with steel toe cap.
2. Work Area Safety: Ensure no persons or animals are within a 15-meter radius. Be aware of your surroundings, including overhead power lines.
3. Fuel Safety: Refuel outdoors only, with engine stopped and cooled. Use clean, fresh fuel mix (see specifications). Wipe off spills.
4. Kickback Zone: Be aware of the upper quadrant of the guide bar tip. Do not let this part contact wood or other objects.

WARNING! A chainsaw is a dangerous tool. Improper use can cause serious injury or death. Never operate when tired, ill, or under the influence of drugs/alcohol.

Assembly & Preparation

Unpack and inspect contents. Assemble on a clean, stable surface.

1. Attach Guide Bar & Chain: Place bar on mounting studs. Loop chain over sprocket and onto bar groove, ensuring cutting teeth face forward on top. Fit clutch cover and tighten nuts finger-tight. Adjust chain tension (see section 9), then fully tighten nuts.
2. Fill Bar & Chain Oil: Use recommended high-quality chain oil. Fill oil tank to capacity.
3. Prepare Fuel Mix: Use unleaded gasoline (min. 90 octane) mixed with a high-quality 2-stroke oil at a 50:1 ratio (2%). Shake well in a separate can before filling saw.
4. Check Controls: Ensure throttle trigger, throttle lockout, chain brake, and stop switch function correctly.

CAUTION! Ensure chain brake is disengaged (pushed forward) before starting. A engaged brake will damage the clutch.

Specifications

• Model: Jonsered 455
• Engine Displacement: 55.5 cm³
• Engine Power: 3.3 kW (4.5 hp)
• Fuel Consumption: Approx. 480 g/kWh
• Idling Speed: 2700 rpm
• Maximum Power Speed: 9000 rpm
• Spark Plug: Champion RCJ7Y or equivalent, gap 0.5 mm (0.020")
• Recommended Fuel Mix: 50:1 (2% oil)
• Sound Pressure Level (LpA): 106 dB(A)
• Sound Power Level (LWA): 121 dB(A)
• Vibration Level (Front/Rear Handle): 3.5/2.5 m/s²

Controls and Components

Familiarize yourself with all controls before starting the engine.

Right Side: Rear handle with throttle trigger and throttle lockout. Stop switch (ON/OFF). Combined choke/stop control lever. Decompression valve button.

Left Side: Front handle with hand guard. Inertia chain brake lever (manual activation). Chain brake status indicator (red band visible when engaged). Side-mounted chain tensioner screw.

Top/Other: Fuel tank cap. Oil tank cap. Air filter cover (quick-release). Spark plug cover. Muffler with spark arrestor screen.

Starting & Stopping Procedure

Cold Start:

1. Place saw on firm, flat ground. Ensure chain is clear of objects.
2. Activate chain brake by pulling hand guard/lever towards front handle (red band visible).
3. Press decompression valve (if equipped).
4. Set combined control lever to full choke position (⬇).
5. Pull starter handle briskly until engine 'fires' (usually 3-5 pulls).
6. Move combined control lever to half-throttle position (⬆).
7. Pull starter handle again until engine starts. Saw will run at high idle.
8. Blip throttle trigger to disengage high idle. Release chain brake before cutting.

Warm Start: Skip steps 4 and 6. Set combined control lever to run position (⬆) and pull starter.

Stopping: Release throttle. Press stop switch to '0' or 'OFF' position.

Operating Instructions

Proper technique is essential for safety and efficiency.

1. Stance & Grip: Stand firmly with feet apart. Grip front handle with left hand, rear handle with right hand. Keep left arm straight to control saw. Hold saw close to your body for better balance.
2. Basic Cutting: Let the chain do the work. Apply light downward pressure. Use the bumper spikes (dogs) to pivot into the wood. Do not force the saw.
3. Kickback Prevention: Always hold saw firmly with both hands. Do not cut with the upper tip of the bar. Be especially cautious when re-entering a previous cut.
4. Felling Trees: For professional use only. Plan escape path. Make notch cut and felling cut according to standard techniques. Use wedges if necessary.
5. Limbing & Bucking: Support logs properly. Cut from top side whenever possible. Be alert for tension/compression in wood.

WARNING! Never operate the chainsaw above shoulder height or with one hand.

Maintenance Schedule

Chain Sharpening & Tensioning

A sharp, properly tensioned chain is critical for safety and performance.

Sharpening: Use a round file matching your chain pitch (e.g., 5/32" for 3/8" pitch). File each cutter from the inside out, maintaining the original angle (typically 30°). File all cutters to the same length. Use a file guide for consistency. Lightly file down depth gauges (rakers) with a flat file and gauge.

Tensioning:

1. Loosen the two nuts on the clutch cover.
2. Using the side-mounted tensioning screw, turn clockwise to tighten until the chain fits snugly against the bar, but can still be pulled around by hand.
3. Lift the tip of the bar and retighten the chain slightly, as it will loosen when lifted.
4. While holding the bar tip up, tighten the two clutch cover nuts securely.

Check tension frequently when chain is new, as it will stretch.

Storage Guidelines

Proper storage prevents fuel system issues and corrosion.

1. Long-term Storage (>30 days):
2. Run the engine until it stops to empty the carburetor of fuel.
3. Drain all fuel from the tank into an approved container.
4. Start the engine again and let it run until it stops to ensure carburetor is dry.
5. Remove chain and bar. Clean thoroughly and coat with oil.
6. Clean the entire saw, especially the air filter and cooling fins.
7. Store in a dry, dust-free place, away from children.
8. Short-term Storage: Simply ensure the fuel cap and oil cap are tight.

CAUTION! Never store the saw with fuel in the tank for extended periods. Old fuel can gum up the carburetor.

Troubleshooting

Service: For repairs beyond basic maintenance, contact an authorized Jonsered service dealer. Use only genuine Jonsered parts.