Certa 62CC 20" Chainsaw - (CTCHNSAW20A) - Manual

Safety and Warnings

• Never operate a chain saw when you are fatigued, ill, upset, under the influence of medication that may make you drowsy, or if you are under the influence of alcohol or drugs.
• Use safety footwear, snug fitting clothing and eye, hearing and head protection equipment.
• Always use caution when handling fuel. Wipe up all spills and then move the chain saw at least three meters from the fueling point before starting the engine.
• Eliminate all sources of sparks or flame (i.e. smoking, open flames, or work that can cause sparks) in the areas where fuel is mixed, poured, or stored.
• Do not smoke while handling fuel or while operating the chain saw.
• Do not allow other persons to be near the chain saw when starting the engine or cutting a wood. Keep bystanders and animals out of the work area. Children, pets, and bystanders should be a minimum of 10 meters away when you start or operate the chain saw.
• Never start cutting until you have a clear work area, secure footing, and planned retreat path from the falling tree.
• Always hold the chain saw firmly with both hands when the engine is running. Use a firm grip with thumb and fingers encircling the chain saw handles.
• Keep all parts of your body away from the saw chain when the engine is running.
• Before you start the engine, make sure the saw chain is not contacting anything.
• Always carry the chain saw with the engine stopped the guide bar and saw chain to the rear, and the muffler away from your body.
• Always inspect the chain saw before each use for worn, loose, or changed parts. Never operate a chain saw that is damaged, improperly adjusted, or is not completely and securely assembled.
• Be sure that the saw chain stops moving when the throttle control trigger is released.
• All chain saw service, other than the items listed in the Operator’s Manual, should be performed by competent chain saw service personnel.
• Always shut off the engine before setting it down.
• Use extreme caution when cutting small size brush and saplings because slender material may catch the saw chain and be whipped toward you or pull you off balance.
• When cutting a limb that is under tension, be alert for spring back so that you will not be struck when the tension in the wood fibres is released.
• Keep the handles dry, clean and free of oil or fuel mixture.
• Operate the chain saw only in well-ventilated areas. Never start or run the engine inside a closed room or building. Exhaust fumes contain dangerous carbon monoxide.
• Do not operate a chain saw in a tree unless specially trained to do so.

Kickback Safety Precautions

• Kickback may occur when the nose or tip of the guide bar touches an object, or when the wood closes in and pinches the saw chain in the cut. Tip contact in some cases may cause a lightning fast reverse reaction, kicking the guide bar up and back towards the operator. Pinching the saw chain along the top of the guide bar may push the guide bar rapidly back towards the operator. Either of these reactions may cause you to lose control of the saw which could result in serious personal injury.
• Do not rely exclusively on the safety devices built into your saw. As a chain saw user you should take several steps to keep cutting jobs free from accident or injury.
• Keep a good grip on the saw with both hands, the right hand on the rear handle, and the left hand on the front handle when the engine is running. Use a firm grip with thumbs and fingers encircling the chain saw handles. A firm grip will help you reduce kickback and maintain control of the saw. Don’t let go.
• Make certain that the area in which you’re cutting is free from obstructions. Do not let the nose of the guide bar contact a log, branch, or any other obstruction which could be hit while you are operating the saw.
• Cut at high engine speeds.
• Do not overreach or cut above shoulder height.
• Follow manufacturers sharpening and maintenance instructions for saw chain.
• Only use replacement bars and chains specified by the manufacturer or the equivalent.

Overview

 

1	Front guard	8	Latch
2	Starter knob	9	Engine switch
3	Air cleaner	10	Fuel tank
4	Choke knob	11	Oil tank
5	Throttle interlock	12	Left handle
6	Right handle	13	Saw chain
7	Throttle lever	14	Guide Bar

For safe operation and maintenance, symbols marked on the machine

(a). The port to refuel the "Mixed Unleaded Petrol"
Position: Fuel cap.

(b). The port to refuel the chain oil
Position: Oil cap.

(c). Put the switch to the "O" position, immediately the engine stops.
Position: Rear-left of the unit.

(d). Starting the engine, if you pull out the choke knob (at the back right of the rear handle) to the point of the arrow, you can set the starting mode as follows

• First-stage position – starting mode when the engine is warm.
• Second-stage position – starting mode when the engine is cool.

Position: Upper-right of the air cleaner cover.

(e). The screw under the "H" stamp is The High-speed adjustment screw. The screw under the "L" stamp is The Slow-speed adjustment screw. The screw at the left of the "T" stamp is the idle adjustment screw.
Position: Left side of the rear handle.

(f). It shows the directions that the chain brake is released (for the white arrow) and activated (for the black arrow).
Position: Front of the chain cover.

Installation

1. Installing guide bar and saw chain

A standard saw unit package contains the items as illustrated. (F1)

(1) Power unit
(2) Guide bar
(3) Saw chain
(4) Plug wrench
(5) Screwdriver for carburettor adjustment

Open the box and install the guide bar and the saw chain on the power unit as follows:

The saw chain has very sharp edges. Use thick protective gloves for safety.

1. Pull the guard towards the front handle to check that the chain brake is not on.
2. Loosen the nuts and remove the chain cover.
3. Gear the chain to the sprocket and, while fitting the saw chain around the guide bar, mount the guide bar to the power unit. Adjust the position of chain tensioner. (F2)

(8) Tensioner nut
(9) Chain cover

Pay attention to the correct direction of the saw chain. (F3)

(1) Moving direction

4. Fit the chain cover to the power unit and fasten the nuts to finger tightness.
5. While holding up the tip of the bar, adjust the chain tension by turning the tensioner screw until the tie straps just touch the bottom side of the bar rail. (F4)

(2) Loosen
(3) Tighten
(4) Tensioner screw

6. Tighten the nuts securely with the bar tip held up (12~15 N•m). Then check the chain for smooth rotation and proper tension while moving it by hand. If necessary, readjust with the chain cover loose.
7. Tighten the tensioner screw.

A new chain will expand its length in the beginning of use. Check and readjust the tension frequently as a loose chain can easily derail or cause rapid wear of itself and the guide bar.

2. Fuel and Chain oil

• Unleaded petrol is very flammable. Avoid smoking or bringing any flame or sparks near fuel. Make sure to stop the engine and allow it cool before refuelling the unit. Select outdoor bare ground for fuelling and move at least 3m away from the fuelling point before starting the engine.

• The chainsaws engines are lubricated by oil specially formulated for air-cooled 2-cycle unleaded petrol engine use. Use anti-oxidant added quality oil expressly labelled for air-cooled 2-cycle engine use. (JASO FC GRADE OIL or ISO EGC GRADE)
• Do not use BIA or TCW (2-stroke water-cooling type) mixed oil.

Recommended mixing ratio - Unleaded petrol 25:Oil 1

• Exhaust emission is controlled by the fundamental engine parameters and components(eq., carbonation, ignition timing and port timing) without the addition of any major hardware or the introduction of an inert material during combustion.
• These engines are certified to operate on unleaded petrol.
• Make sure to use unleaded petrol with a minimum octane number of 89 RON. If you use unleaded petrol of a lower octane value than recommended, there is a danger that the engine temperature may rise and an engine problem such as piston seizing may consequently occur.
• Unleaded petrol is recommended to reduce the contamination of the air for the sake of your health and the environment.
• Poor quality unleaded petrol or oils may damage sealing rings, fuel lines or fuel tank of the engine.

Mixing Fuel

Pay attention to mixing.

1. Measure out the quantities of unleaded petrol and oil to be mixed.
2. Put some of the unleaded petrol into a clean, no corrosive fuel container.
3. Pour in all of the oil and mix well.
4. Pour In the rest of unleaded petrol and agitate again for at least one minute. As some oils may be difficult to mix depending on oil ingredients, sufficient agitation is necessary for the engine to last long. If the mix is insufficient, there is an increased danger of early piston seizing due to abnormally lean mixture.
5. Put a clear indication on the outside of the container to avoid mixing up with unleaded petrol or other containers.

Fueling the unit

1. Untwist and remove the fuel cap. Rest the cap on a dustless place.
2. Put fuel into the fuel tank to 80% of the full capacity.
3. Fasten the fuel cap securely and wipe up any fuel spillage around the unit.
4. Select bare ground for fueling.
5. Move at least 3 meters away from the fueling point before starting the engine.
6. Stop the engine before refuelling the unit. At that time, be sure to sufficiently agitate the mixed unleaded petrol in the container.

For long engine life, avoid

1. Fuel with no oil (raw unleaded petrol) - It will cause severe damage to the internal engine parts very quickly.
2. Gasohol – It can cause deterioration of rubber and/or plastic parts and disruption of engine lubrication.
3. Oil for 4-Cycle engine use – It can cause spark plug fouling, exhaust port blocking, or piston ring sticking.
4. Mixed fuels which have been left unused for a period of one month or more may clog the carburettor and result in the engine failing to operate properly.

Operation

It is very dangerous to run a chainsaw that has broken parts or lacks any parts. Before starting the engine, make sure that all the parts including bar and chain are installed properly.

Starting the Engine

1. Fill fuel and chain oil tanks respectively, and tighten the caps securely. (F7)

(1) Chain oil
(2) Fuel

2. Put the switch to "I" position. (F8)

(3) Switch

3. Pull out the choke knob to the second-stage position. The choke will close and the throttle lever will then be set in the starting position [F10-(a)].

(4) Throttle lever
(5) Throttle interlock
(6) Choke knob

When restarting immediately after stopping the engine, Choke knob in the first-stage position (chokes open and throttle lever in the starting position).

Once the choke knob has been pulled out, it will not return to the operating position even if you press down on it with your finger. When you wish to return the choke knob to the operating position, pull out the throttle lever instead.

4. While holding the saw unit securely on the ground, pull the starter rope quickly. (F11)

5. When the engine has ignited, push in the choke knob to the first-stage position and pull the starter again to start the engine.
6. Allow the engine to warm up with the throttle lever pulled slightly.

Keep clear of the saw chain as it will start rotating upon starting of the engine.

Checking oil supply

Make sure to install the guide bar chain when checking the oil supply. If not, the rotating parts may be exposed. It is very dangerous. After starting the engine, run the chain at medium speed and see if chain oil is scattered off as shown in the figure. (F12)

(1) Chain oil

The chain oil flow can be changed by inserting a screwdriver in the hole on bottom of the clutch side. Adjust according to your work conditions.
(OP8)
(1) Chain oil flow adjusting shaft
(a) Rich
(b) Lean

NOTE
The oil tank should become nearly empty by the time fuel is used up. Be sure to refill the oil tank every time when refuelling the saw.

Adjusting the Carburettor(F14)

(1) L needle
(2) H needle
(3) Idle adjusting screw

The carburettor on your unit has been factory adjusted but may require fine tuning due to change in operating conditions. Before adjusting the carburettor, make sure that the machine is receiving clean air and fresh fuel.

When adjusting, take the following steps:

Be sure to adjust the carburettor with the bar chain attached.

1. H and L needles are restricted within the number of turns as shown below. H needle –1/4 L needle fixed
2. Start the engine and allow it to warm up in low speed for a few minutes.
3. Turn idle adjusting screw (T) counter-clockwise so that saw chain does not turn. If idling speed is too slow, turn the screw clockwise.
4. Make a test cut adjust the H needle for best cutting power, not for maximum speed.

Chain brake

 This machine is equipped with an automatic brake to stop saw chain rotation upon the occurrence of kickback while in saw cutting operation. The brake is automatically operated by inertial force which acts on the weight fitted inside the front guard. This brake can also be operated manually with the front guard pushed down to the guide bar. To release the brake, pull up the front guard toward the front handle till a "click" sound is heard. (F15)

Be sure to confirm brake operation is working with the daily inspection

1. Turn off the engine.
2. Holding the chain saw horizontally, release your hand from the front handle, hit the tip of the guide bar to a stump or a piece of wood, and confirm brake operation. Operating level varies by bar size. (F16)

In case the brake is not effective, contact customer support for inspection and repair. The engine is kept rotated at high speed with the brake engaged, heats the clutch, causing trouble. When the brake is operated while in the engine is running, immediately release your fingers from the throttle lever and stop the engine.

Stopping engine

1. Release the throttle lever to allow the engine to idle for a few minutes.
2. Put the switch to the "O" (STOP) position. (F17)

(1) Switch

Sawing

• Always follow the safety regulations. The chain saw must only be used for cutting wood. It is forbidden to cut other types of material. Vibrations and kickback vary with different materials and the requirements of the safety regulations would not be respected. Do not use the chain saw as a lever for lifting, moving or splitting objects. Do not lock it over fixed stands. It is forbidden to hitch tools or applications to the P.t.o. that are not specified by the manufacturer.
• It is not necessary to force the saw into the cut. Apply only light pressure while running the engine at full throttle.
• When the saw chain is caught in the cut, do not attempt to pull it out by force, but use a wedge or a lever to open the cut to release the blade.

Felling a Tree (F22)

(1) Notch cut
(2) Felling cut
(3) Felling direction

1. Decide the felling direction considering the wind, lean of the tree, location of heavy branches, ease of job after felling and other factors.
2. While clearing the area around the tree, arrange a good foothold and retreat path.
3. Make a notch cut one-third of the way into the tree on the felling side.
4. Make a felling cut from the opposite side of the notch and at a level slightly higher than the bottom of the notch.

When you fell a tree, be sure to warn your neighbouring workers of the danger.

Bucking and Limbing

• Always ensure your foothold. Do not stand on the log.
• Be alert to the rolling over of a cut log. Especially when working on a slope, stand on the uphill side of the log.
• Follow the instructions in "For Safe Operation" to avoid kickback of the saw. Before starting work, check the direction of bending force inside the log to be cut. Always finish cutting from the opposite side of bending direction to prevent the guide bar from being caught in the cut.

A Log Lying On the Ground(F23)

Saw down halfway, then roll the log over and cut from the opposite side.

A Log Propped Off the Ground(F24)

In area A, saw up from the bottom one-third and finish by sawing down from the top. In area B, saw down from the top one-third and finish by sawing up from the bottom.

Cutting Limb of a Fallen Tree (F25)

First check to which side the limb is bent. Then make the initial cut from the bent side and finish by sawing from the opposite side.

Be alert to the springing back of a cut limb.

Pruning of Standing Tree (F26)

Cut up from the bottom, finish down from the top.

• Do not use an unstable foothold or ladder.
• Do not overreach.
• Do not cut above shoulder height.
• Always use your both hands to grip the saw.

Maintenance

Maintenance, replacement, or repair of the emission control device and systems may be performed by any non-road engine repair establishment or individual.

Before cleaning, inspecting or repairing your unit, make sure that engine has stopped and is cool. Disconnect the spark plug to prevent accidental starting.

Maintenance After Each Use

1. Air Filter

Dust on the filter surface can be removed by tapping a corner of the filter against a hard surface. To clean dirt in the meshes, split the filter. When using compressed air, blow from the inside. (F27)

To assemble the filter halves, press the rim until it clicks.

When installing the main filter, make sure that the grooves on the filter edge are correctly fit with the projections on the cylinder cover.

2. Oiling Port

(1) Oiling port

Dismount the guide bar and check the oiling port for clogging. (F28)

3. Guide bar

When the guide bar is dismounted, remove sawdust in the bar groove and the oiling port. (F29)

(1) Oiling port

Grease the nose sprocket from the feeding port on the tip of the bar. (F30)

(2) Grease port
(3) Sprocket

4. Others

 Check for fuel leakage and loose fastenings and damage to major parts, especially handle joints and guide bar mounting. If any defects are found, make sure to have them repaired before operating again.

Periodical Service Points

1. Cylinder Fins

Dust clogging between the cylinder fins will cause overheating of the engine. Periodically check and clean the cylinder fins after removing the air cleaner and the cylinder cover. When installing the cylinder cover, make sure that switch wires and grommets are positioned correctly in place. (F31)

 

Be sure to block the air intake hole during cleaning.

2. Fuel filter

(a) Using a wire hook, take out the filter from the filler port. (F32)

(1) Fuel filter

(b) Disassemble the filter and wash with unleaded petrol, or replace with a new one if needed.

• After removing the filter, use a pinch to hold the end of the suction pipe.
• When assembling the filter, take care not to allow filter fibres or dust inside the suction pipe.

3. Oil tank

With a wire hook, take out the oil filter through the filler port and clean in unleaded petrol. When putting the filter back into the tank, make sure that it comes to the front right corner. Also, clean off the dirt in the tank. (F33)

(2) Oil filter

4. Spark plug (F34)

Clean the electrodes with a wire brush and reset the gap to 0.65 mm as necessary.

 

5. Sprocket

Check for cracks and for excessive wear interfering with the chain drive. If the wearing is found obviously, replace it with a new one. Never fit a new chain on a worn sprocket or a worn chain on a new sprocket.

6. Front and rear dampers

Replace if the adhered part is peeled or crack is observed on the rubber part.

7. Saw Chain

It is very important to keep the saw cutters sharp to ensure smooth and safe operation.
Your cutters need to be sharpened when:

• Sawdust becomes powder-like.
• You need extra force to saw in.
• The cut does not go straight.
• Vibration increases.
• Fuel consumption increases.

Cutter setting standards:

Be sure to wear safety gloves.

Before filing:

• Make sure the saw chain is held securely.
• Make sure the engine is stopped.
• Use a round file of proper size for your chain.

Chain type: 91VG
File size: 5/32 in (4.0mm)

Place your file on the cutter and push straight forward. Keep the file position as illustrated. (F36)

After every cutter has been set, check the depth gauge and file it to the proper level as illustrated.(F37)

(1) Appropriate gauge checker
(2) Make the shoulder round
(3) Depth gauge standard

Be sure to round off the front edge to reduce the chance of kickback or tie-strap breakage.

(4) Cutter length
(5) Filing angle
(6) Side plate angle
(7) Top plate cutting angle

Make sure every cutter has the same length and edge angles as illustrated. (F38)

Guide bar

• Reverse the bar occasionally to prevent partial wear.
• The bar rail should always be a square. Check for wear of the bar rail. Apply a ruler to the bar and the outside of a cutter. If a gap is observed between them, the rail is normal. Otherwise, the bar rail is worn. Such a bar needs to be corrected or replaced. (F39)

(1) Ruler
(2) Gap
(3) No gap
(4) Chain tilts

Storage

For long term storage:

1. Empty the fuel tank and run the engine out of fuel.
2. Empty the oil tank.
3. Clean the entire unit.
4. Store the unit in a dry place out of the reach of children.

Troubleshooting

Issue	Cause	Solution
Start Failure	Check fuel for water or substandard mixture.	Replace with proper fuel.
	Check for engine flooding.	Remove and dry the spark plug. Then pull the starter again with no choke.
	Check the spark.	Replace with a new plug.
Lack of power/Poor acceleration/Rough idling	Check fuel for water or substandard mixture.	Replace with proper fuel.
	Check air filter and fuel filter for clogging.	Clean the filter
	Check carburettor for inadequate adjustment.	Readjust carburettor
Oil does not come out	Check oil for substandard quality.	Replace oil
	Check oil passage and ports for clogging.	Clean ports