Jonsered 520SP Chainsaw Manual

The Jonsered 520SP is a professional-grade chainsaw designed for demanding forestry and arborist work. It features a powerful 2-stroke engine, robust construction, advanced anti-vibration system, automatic chain oiler, and safety features including a chain brake and throttle lockout. Below are key sections for safety, features, assembly, operation, maintenance, and troubleshooting.

1. Features at a Glance 2. Safety Information 3. Assembly & Preparation 4. Specifications 5. Controls and Components 6. Starting & Operating 7. Maintenance Schedule 8. Chain & Bar Care 9. Storage Guidelines 10. Warranty Information 11. Troubleshooting

Features at a Glance

Key components: Professional 2-stroke engine, Chain brake, Automatic chain oiler, Anti-vibration system, Quick-stop inertia brake, Side-access chain tensioner.

Feature	Description
Engine Type	2-stroke, air-cooled gasoline engine
Displacement	52.1 cc
Power Output	3.2 kW (4.3 hp)
Fuel Tank Capacity	0.55 liters
Oil Tank Capacity	0.26 liters
Recommended Bar Length	15" to 20" (38 cm to 50 cm)
Chain Pitch	3/8" or .325"
Weight (without bar & chain)	5.9 kg
Ignition System	Electronic, capacitor discharge
Vibration Dampening	Advanced anti-vibration handles

Safety Information

Read all instructions before use. Always wear appropriate PPE.

Personal Protective Equipment (PPE): Wear safety helmet with face shield and hearing protection, cut-resistant gloves, chainsaw chaps, and steel-toe boots.
Work Area Safety: Clear area of bystanders, especially children. Ensure secure footing.
Kickback Prevention: Hold saw firmly with both hands. Do not cut with tip of bar. Maintain sharp chain.
Fuel Safety: Refuel in well-ventilated area with engine off and cool. Use approved fuel mix.

WARNING! Chainsaws are dangerous. Failure to follow safety instructions can result in serious injury or death.

Assembly & Preparation

Unpack and inspect contents. Assemble bar and chain.

Attach Guide Bar: Place bar onto mounting studs, ensuring tensioning pin engages in bar hole.
Install Chain: Fit chain over bar sprocket and onto drive sprocket, with cutting teeth facing forward on top of bar.
Tension Chain: Use side-mounted tensioning screw to adjust. Chain should snap back when pulled from bar.
Fill Fluids: Add recommended 2-stroke fuel mix (50:1 Jonsered oil to unleaded gasoline) to fuel tank. Fill chain oil tank with bar and chain oil.

CAUTION! Ensure chain brake is disengaged (pushed forward) during assembly.

Specifications

Model: Jonsered 520SP
Engine Displacement: 52.1 cc
Power Output: 3.2 kW (4.3 hp) @ 9,000 rpm
Idle Speed: 2,700 rpm
Max Power Speed: 9,500 rpm
Fuel Consumption: Approx. 560 g/kWh
Sound Pressure Level: 112 dB(A)
Vibration Level (front/rear handle): 4.5/2.5 m/s²
Spark Plug: Champion RCJ7Y or equivalent
Recommended Fuel Mix: 50:1 (2% oil)

Controls and Components

Main Controls: Front Handle with throttle trigger, Rear Handle, Chain brake lever, Throttle lockout, Stop switch, Choke control, Decompression valve (if equipped).

Safety Features: Chain brake (manual/inertia activated), Throttle lockout (must be pressed to engage throttle), Right-hand guard.

Maintenance Points: Air filter cover, Spark plug, Chain tensioner, Chain oiler adjustment, Fuel and oil caps.

Starting & Operating

Cold Start Procedure (with decompression valve):

Place saw on firm, level ground. Engage chain brake.
Press decompression valve (if equipped). Set choke to full position. Set stop switch to "I".
Press throttle lockout and pull throttle trigger once to set fast idle.
Place foot in rear handle, hold front handle firmly. Pull starter cord sharply until engine fires.
Move choke to half position. Pull starter cord again until engine starts.
Blip throttle to disengage fast idle. Disengage chain brake before cutting.

Tip: Warm start: Do not use choke. Set stop switch to "I" and pull starter cord.

Maintenance Schedule

Supports long life with regular maintenance.

Interval	Task
Daily	Check chain tension and sharpness; Clean air filter; Check fuel and oil levels.
Every 10 hours	Clean spark arrestor screen (if equipped).
Every 20 hours	Clean cooling fins; Check spark plug condition/gap.
Every 50 hours	Clean fuel filter; Check all nuts and bolts for tightness.
Every 100 hours	Replace fuel filter; Clean carburetor air intake.
Annually	Professional servicing recommended.

WARNING! Always disconnect spark plug wire before performing maintenance.

Chain & Bar Care

Sharpening: Use correct round file size (typically 4.0mm or 4.8mm). Maintain correct filing angle (typically 30°). File all cutters to equal length.

Bar Maintenance: Clean bar groove regularly. Flip bar weekly for even wear. Lubricate bar nose sprocket.

Chain Tension: Adjust when chain is warm. Proper tension: chain should be snug against bar but pull freely by hand.

Storage Guidelines

Long-term Storage (over 30 days):

Drain fuel tank and run engine until it stops to clear carburetor.
Remove spark plug, add a teaspoon of engine oil into cylinder, pull starter cord slowly 2-3 times, reinstall plug.
Clean entire saw, especially cooling fins and air filter.
Remove chain, clean and soak in oil. Store bar and chain in oiled paper.
Store in dry, cool place, protected from dust.

CAUTION! Never store with fuel in tank for extended periods.

Warranty Information

Jonsered 520SP Professional Warranty: Limited warranty for professional use, typically 1 year from date of purchase. Warranty covers defects in materials and workmanship under normal use. Not covered: damage from misuse, neglect, improper maintenance, unauthorized repairs, or use of non-genuine parts. Proof of purchase required. For warranty service, contact an authorized Jonsered service dealer.

Troubleshooting

Symptom	Possible Cause	Corrective Action
Engine will not start	No spark, flooded, fuel issue	Check spark plug; Use correct starting procedure; Ensure fresh fuel mix; Check fuel filter.
Engine starts then dies	Clogged air/fuel filter, carburetor	Clean/replace air filter; Check fuel filter; May need carburetor adjustment.
Loss of power	Dirty air filter, clogged spark arrestor, dull chain	Clean air filter and spark arrestor screen; Sharpen chain.
Chain does not oil	Empty oil tank, clogged oiler, wrong oil	Fill tank; Clean oil holes in bar; Use correct bar & chain oil; Check oil pump.
Excessive vibration	Loose components, unbalanced chain, damaged AV mounts	Tighten all bolts and handles; Balance chain; Inspect anti-vibration mounts.
Chain throws off bar	Loose bar nuts, worn bar, improper tension	Tighten bar nuts; Check bar for wear; Adjust chain tension correctly.

Service: For repairs beyond basic maintenance, contact an authorized Jonsered service dealer.

Support: Visit www.jonsered.com or contact your local authorized dealer.