Black Max BM5020 - User Manual

To Next Page

OPERATOR’S MANUAL

MANUAL DEL OPERADOR

BM5020

20 in. 50cc Chain Saw

Motosierra de 50 cm (20 pulg.), 50 cc

ENGINE FAMILY: *HCPS.0505CA

FAMILIA DE MOTOR: *HCPS.0505CA

WARNING: To reduce the risk of injury, the user must

read and understand the operator’s manual before using this

product.

ADVERTENCIA: Para reducir el riesgo de lesiones,

el usuario debe leer y comprender el manual del operador antes

de usar este producto.

TABLE OF CONTENTS

 General Safety Rules ............................................................2-3

 Specific Safety Rules ............................................................3-4

 Symbols ................................................................................5-6

 Glossary of Terms ....................................................................7

 Features ................................................................................8-9

 Assembly ...............................................................................10

 Operation ..........................................................................10-24

 Maintenance .....................................................................24-36

 Bar and Chain Combinations .................................................37

 Troubleshooting ................................................................37-38

 Parts Ordering/Service ............................................. Back Page

ÍNDICE DE CONTENIDO

 Reglas de seguridad generales ...........................................2-3

 Reglas de seguridad específicas .........................................4-5

 Símbolos ..............................................................................6-7

 Glosario de términos ............................................................... 8

 Características ...................................................................9-10

 Armado ................................................................................. 11

 Funcionamiento ...............................................................11-26

 Mantenimiento .................................................................26-39

 Combinaciones de barra y cadena ....................................... 40

 Corrección de problemas ................................................40-41

 Pedidos de piezas/servicio ................................ Pág. posterior

SAVE THIS MANUAL FOR

FUTURE REFERENCE

GUARDE ESTE MANUAL

PARA FUTURAS CONSULTAS

NOTICE AVISO

Do not use E15 or E85 fuel in

this product. It is a violation of

federal law and will damage the

unit and void your warranty. Only use unleaded gasoline

containing up to 10% ethanol.

No utilice combustibles E15 o E85 con este producto. Esto

constituye una violación a la ley federal, dañará la unidad y

anulará la garantía. Utilice únicamente gasolina sin plomo

que contiene hasta 10% de etanol.

To register your Black Max product, please visit:

www.blackmaxtools.com

Para registrar su producto de Black Max, por favor visita:

www.blackmaxtools.com

Need help?

Do you have a question about the Black Max BM5020 and is the answer not in the manual?

The Black Max BM5020 is a 20-inch, 50cc gas-powered chain saw designed for infrequent use by homeowners, cottagers, and campers for general applications such as clearing, pruning, and cutting firewood. It is not intended for prolonged use, as extended operation periods can cause circulatory problems in the user's hands due to vibration. For such use, a product with an anti-vibration feature may be more appropriate.

Function Description:

The chain saw is a two-handed tool used for cutting wood. It operates with a 2-cycle engine that requires a pre-mixed gasoline and 2-cycle lubricant fuel. The saw features an automatic oiler system that lubricates the chain only when it is moving, driven by the sprocket. A chain brake is incorporated to quickly stop the saw chain from rotating, engaging when the front hand guard/chain brake is pushed toward the bar. The throttle trigger controls chain rotation, while a primer bulb pumps fuel from the tank to the carburetor. Felling direction sights assist in aligning the saw during tree felling.

Important Technical Specifications:

Bar length: 20 inches (50 cm)
Engine displacement: 50cc
Chain pitch: 0.325 inches (8.3 mm)
Chain gauge: 0.050 inches (1.27 mm)
Chain type: Standard
Drive sprocket: 7-tooth
Chain drive links: 78
Idle engine speed: 2,600-3,400 RPM
Fuel tank capacity: 19.4 oz (575 ml)
Chain lubricant tank capacity: 11.8 oz (350 ml)
Fuel requirement: Unleaded gasoline with up to 10% ethanol, octane rating of 87 [(R + M)/2] or higher, pre-mixed with a high-quality 2-cycle lubricant at a 50:1 ratio (2.6 oz per US gallon or 20 ml per liter). E15 or E85 fuels are not to be used.
Spark plug: Champion RCJ6Y or RYOBI AC00160A with a 0.025-inch (0.64 mm) electrode gap.
Classification: CSA Z62.1-15 Class 1C saw.

Usage Features:

The BM5020 is designed for safe and effective wood cutting. Users must read and understand the operator's manual before use.

Starting the Engine: The starting procedure varies for cold and warm engines. For a cold engine, the chain brake must be in the run position, the primer bulb pressed and released 10 times, and the choke lever pulled to FULL CHOKE. The starter grip and rope are then pulled until the engine attempts to start (no more than 3-5 times depending on temperature), after which the choke lever is moved to RUN, and the starter pulled until the engine runs. For a warm engine, the chain brake is in run, the choke lever is pulled to FULL CHOKE then immediately pushed to RUN for fast idle, and the starter pulled until the engine runs (no more than 5 times).
Stopping the Engine: Release the throttle trigger to allow the engine to idle, then fully press the stop switch. For additional safety, engage the chain brake when the saw is not in use.
Adjusting Idle Speed: The idle speed screw "T" can be turned clockwise to increase idle speed or counterclockwise to decrease it. The saw chain should never turn at idle.
Proper Grip and Stance: Always hold the saw firmly with both hands, left hand on the front handle and right hand on the rear handle, with the body to the left of the chain line. Maintain a balanced stance with both feet on solid ground.
Cutting Techniques: Basic cutting procedures involve taking a proper stance, accelerating to full throttle just before entering the cut, maintaining full throttle during the cut, and allowing the chain to cut with light downward pressure. The saw should not be forced.
Felling Trees: Requires careful planning, including assessing wind, tree lean, and a clear retreat path. A notched undercut (1/3 diameter) and a felling backcut (at least 2 inches above the notch) are crucial. A "hinge" of wood must be left between the notch and backcut to control the tree's fall.
Bucking: Cutting a fallen tree into lengths. Small logs should be supported. The safety tip anti-kickback nose guard should remain attached to prevent kickback. When bucking on a slope, stand on the uphill side of the log.
Limbing: Removing branches from a fallen tree. Work slowly, keeping both hands on the saw. Cut limbs one at a time, removing cut limbs from the work area. Branches under tension should be cut from the bottom up.
Pruning: Trimming limbs from a live tree. Do not cut from a ladder or above chest height. Make initial cuts further out on the limb to reduce weight before making the finishing cut against the main member.
Cutting Springpoles: Extreme caution is advised as springpoles (bent or trapped trees/limbs under tension) can spring back rapidly, causing serious injury.

Maintenance Features:

Regular maintenance is crucial for the product's performance, safety, and longevity.

General Maintenance: Avoid solvents on plastic parts. Clean with cloths. All bearings are pre-lubricated for life.
Replacing Guide Bar and Chain: Stop the engine, disconnect the spark plug wire, and ensure the chain brake is in the RUN position. Wear gloves. Remove bar mounting nuts and clutch cover. Replace the old chain with a specified low-kickback chain, ensuring cutters face the direction of rotation. Position the chain drive links in the bar groove and around the sprocket. Reinstall the clutch cover, aligning the adjusting pin and bar studs.
Adjusting Chain Tension: Check tension before each use. A cold chain should be snug with no slack, turning by hand without binding. A warm chain should have tie strap flats hanging approximately 0.050 inches out of the bar groove. Adjust by loosening bar nuts, raising the guide bar tip, and turning the chain tensioning screw clockwise until proper tension is achieved, then tighten bar nuts.
Chain Maintenance: Use only a low-kickback chain. Sharpen the chain when wood chips are small/powdery, the chain must be forced through wood, or it cuts to one side. Use a 3/16-inch round file and holder, filing all cutters to a 30° top plate angle and 80° side plate angle. Maintain a raker (depth gauge) clearance of 0.025 inches using a flat file and depth gauge jointer.
Guide Bar Maintenance: Clean and inspect daily for wear/damage. Smooth feathering or burring with a file. Weekly, reverse the guide bar, lubricate the sprocket hole, and check lubrication holes/chain groove for impurities. Replace if worn, bent, cracked, broken, or spread rails.
Safety Tip Nose Guard Maintenance: Check tightness of the mounting screw before each use. Tighten with a wrench until snug, then an additional 3/4 turn. Replace the screw and safety tip if tightness cannot be achieved.
Air Filter Cleaning: Push down and rotate the knob on the air filter cover counterclockwise to unlock and remove. Brush/blow loose dirt from the carburetor area. Remove the air filter (after pulling choke rod out to prevent contamination). Clean by tapping, washing with soapy water (every 5 hours), or using compressed air. Replace every 25 hours.
Starter Unit Cleaning: Use a brush or compressed air to keep cooling vents free of debris.
Engine Cleaning: Periodically clean cylinder and flywheel fins with compressed air or a brush to prevent overheating.
Fuel Filter Checking: Periodically check for contamination/damage and replace if necessary.
Spark Plug Replacement: Replace every 25 hours or more frequently. Use a Champion RCJ6Y or RYOBI AC00160A with a 0.025-inch gap. Allow the engine to cool before removal.
Exhaust Port, Muffler, and Spark Arrestor Cleaning: The spark arrestor (USDA Forest Service evaluated) must be cleaned/replaced every 50 hours or yearly to ensure proper performance and comply with fire prevention regulations. Carbon deposits in the exhaust port/muffler may need professional removal to restore power.
Chain Brake Inspection and Cleaning: Remove the clutch cover and clean components. Check brake band for wear (thickness should not be less than 0.024 inches). Keep the mechanism clean and lightly brush the linkage. Test performance after cleaning.
Storage: Clean all foreign material. Store in a well-ventilated, child-inaccessible area, away from corrosive agents. Comply with fuel storage regulations. For storage longer than 1 month, drain all fuel and lubricant, run the engine until it stops, and purge the primer bulb. Always place the scabbard over the guide bar and chain.
High Altitude Operation: For operation above 2000 feet, have an authorized service center adjust the engine. Running an unadjusted engine at high altitudes can result in poor performance and increased emissions. An engine adjusted for high altitudes cannot be run at 2000 feet or lower without risk of overheating and damage.