Chain Saw Use and Maintenance
Contents
1. Chapter objectives e Students will learn how to remove the bar and the chain inspect them for damage and wear and clean them e Students will learn how to remove and clean or re place the air and fuel filters e Students will learn how to inspect the power head for loose bolts and damage e Students will learn how to replace the bar and the chain e Students will learn how to file the chain Chain Saw Operation The bar and chain are the most important parts of your chain saw A sharp chain produces shavings that fall to the ground away from the power head A clean bar in good condition guides the chain through the cut making a Straight true cut A dull chain produces sawdust that gets sucked into the air filter reducing power by limiting the airflow to the power head A dull chain does not allow the saw to cut smoothly and puts unnecessary strain on the power head The sawyer is forced to saw into the cut increasing the stress on the power head An improperly maintained bar and chain will damage the chain saw As the sawyer works harder to make the saw cut the sawyer may become fatigued increasing the risk of accident or injury A dull chain also increases the risk of kickback The primary purpose of the chain saw and crosscut saw training and certification program is to provide for yyy Chapter 3 Chain Saw Use and Maintenance Suggested time 2 hours the safety of all employees who operate saws S2. In addition the chain may be thrown because the chain tension is harder to control e Rails are worn down and the groove becomes shal low If the groove is too shallow and the tie straps do not touch the rails replace the bar e The outside edges of the rails develop wire edges Use a flat file to remove them e The rail is worn low on one side This causes the chain to cut at an angle The bar will have to be ground on a specialized bar grinder You may need to take the bar to a dealer or to a trained saw mechanic if your unit doesn t have a specialized bar grinder Chapter 3 Chain Saw Use and Maintenance e The rails show blue discoloration along the bar or at the tip of the sprocket nose This discoloration is caused by lack of lubrication by poor cutting methods that push the drive links to the side by a chain that is too tight or by a dull or improperly filed chain Blue spots are caused by excess heat The spots are soft and will wear rapidly you will need to replace the bar CORRECT INCORRECT Low rail SQUARE BAR RAILS ar a GROOVE WIDTH abpaybrens abparybrens N No i Clearance clearance leans Tie straps do not ride eZ on bar rails q m ie straps fit on rails a GROOVE DEPTH OO KOO C Pe Equal RAIL THICKNESS Straightedge Ee BENT Gap Straightedge No gap STRAIGHT Figure 3 8 Correcting these rail conditions will prevent damage to th
3. permission by Blount Inc 28 cutting angle Top plate filing angle Figure 3 10 Maintain the top plate cutting angle top plate filing angle and side plate angle Oregon Maintenance and Safety Manual permis sion by Blount Inc Sharpening Cutters With a Round File Be sure that the chain is tensioned properly The file must be held at least one fifth of the file s diameter above the cutter s top plate figure 3 11 The clamp on file guide positions the file for you One fifth or 20 percent above top plate Figure 3 11 Hold the file at least one fifth of the file s diameter above the cutter s top plate Oregon Maintenance and Safety Manual permis sion by Blount Inc Chapter 3 Chain Saw Use and Maintenance Maintain the correct top plate angle as marked on the file guide by keeping the filing angle parallel with the chain figure 3 12 Figure 3 12 The correct top plate angle is marked on the file guide Oregon Maintenance and Safety Manual permission by Blount Inc Sharpen cutters on one side of the chain first filing from the inside of each cutter to the outside Turn the saw around and repeat the process for the remaining side figure 3 13 Figure 3 13 Sharpen the cutters on one side of the chain before turning the saw around to sharpen the other side Oregon Maintenance and Safety Manual permission by Blount Inc 29 Chapter 3 Chain Saw Use and
4. Maintenance If the chrome surface of the top or side plates has been chipped file until the chip has been removed from the chrome surface Keep the length of all cutters equal figure 3 14 Figure 3 14 All cutters should be the same length Oregon Maintenance and Safety Manual permission by Blount Inc How To Set Depth Gauges Use a depth gauge tool with the correct built in setting for the chain Place the tool on top of the chain so one depth gauge protrudes through the slot in the tool figure 3 15 Figure 3 15 A depth gauge protrudes through the slot in the depth gauge tool Oregon Maintenance and Safety Manual permission by Blount Inc If the depth gauge extends above the slot use a flat file to file the depth gauge level with the top of the tool Never file a depth gauge lower than the top of the tool After lowering a depth gauge round off its leading edge figure 3 16 30 Figure 3 16 After lowering a depth gauge always round off its leading edge Oregon Maintenance and Safety Manual permission by Blount Inc Chain Filing Exercise e Wear appropriate gloves for hand protection as de scribed in your JHA e Make sure the chain is tensioned properly e Maintain the correct top plate angle as marked on the file guide by keeping the filing angle parallel with the chain e File one side of the chain then the other e Keep the length of all cutters equal e Set depth g
5. hazards by requiring them to wear the appropriate PPE Always position your body securely while working with a tool Never chop crosshanded always use a natural striking action Be alert when working on hillsides or uneven ground If you cut a sapling that is held down by a fallen log the sapling may spring back Be alert for sudden breakage If you do not need to cut something leave it alone 34 Never use chopping tools as wedges or mauls Do not allow two persons to chop or drive wedges together on the same tree When chopping limbs from a felled tree stand on the opposite side of the log from the limb being chopped and swing toward the top of the tree or branch Do not allow the tool handle to drop below a plane that is parallel with the ground unless you are chopping on the side of a tree opposite your body If the cutting edge picks up a wood chip stop Remove the chip before continuing To prevent blows from glanc ing keep the striking angle of the tool head perpendic ular to the tree trunk Wedges Wedges are essential tools for safe felling and bucking They provide a way to lift the tree preventing the tree from sitting back when it is being felled A wedge must be inserted into the back cut as soon as possible Wedges also reduce binds on the saw when bucking logs Select the correct wedge for the job The proper type size and length or a wedge varies depending on its use The size of the tree being fel
6. safely start and operate a saw can vary with the make and model Starting Procedures Take extra care when starting your chain saw Because you wort have both hands on the saw you will need to be more careful to maintain complete control Remember that on off switches may vary with differ ent makes of saws e Ensure that appropriate PPE is available and is worn correctly e Maintain a secure grip on the saw at all times e Always start the saw with the chain brake engaged e Start the saw on the ground or where it is supported firmly with the nose of the saw bar over a stump or log To successfully start a cold saw feather the throt tle trigger Avoid engaging the throttle lock or the fast idle position of the on off switch e Make sure that the saw s bar and chain do not contact anything Chapter 3 Chain Saw Use and Maintenance e Drop starting a chain saw is strictly forbidden Do not drop start a chain saw This is the most danger ous method of starting a saw because you have no control of the saw Starting the Chain Saw on the Ground e Set the chain brake e Place the saw on firm ground in an open area figure 3 17 e Grip the front handlebar firmly with your less domi nant hand e Pull the starting rope with your dominant hand until you feel resistance e Give a strong brisk pull Gradually return the start ing rope to the saw housing Do NOT allow the start ing rope to snap b
7. than the chisel and the chipper cutters Oregon Maintenance and Safety Manual permission by Blount Inc Parts of the chain figure 3 5 Preset tie strap Preset left hand Tie strap Right hand cutter Drive link Figure 3 5 Parts of the chain Oregon Maintenance and Safety Manual permission by Blount Inc Tie strap Holds the parts of the saw chain together Drive link Fits in the bar groove so the bar can guide the chain and into the chain sprocket so the power head can drive the chain around the bar Cutter sequences figure 3 6 ii Rok Semiskip Figure 3 6 The cutter sequences for three types of chains stan dar d semiskip and skip full skip Oregon Maintenance and Safety Manual permission by Blount Inc Standard This chain has a cutter sequence of left hand cutter tie strap right hand cutter tie strap left hand cutter tie strap right hand cutter for the length of the chain Semiskip This chain has a cutter sequence of left hand cutter two tie straps right hand cutter one tie strap left hand cutter two tie straps right hand cutter one tie strap left hand cutter for the length of the chain Skip or full skip This chain has a cutter sequence of left hand cutter two tie straps right hand cutter two tie straps for the length of the chain Guide bar The guide bar supports and guides the saw chain The most common types of bars ar
8. 20 Figure 3 20 Pull in occurs when the chain on the bottom of the bar is suddenly stopped by contacting another object or by being pinched From Chain Safety Manual permission by Stihl Inc 33 Chapter 3 Chain Saw Use and Maintenance Ways to avoid pull in Always start a cut with the chain at or near full speed and with the bumper spikes dogs contacting the wood Watch the cut and the log for any movement that may pinch the bar Use wedges to keep the cut open Additional Tools This section includes information about axes wedges approved safety containers for fuel and oil peaveys and cant hooks Axes Axes are used to remove bark from trees and to drive wedges during felling and bucking The ax han dle should be smooth and free of cracks The head should be securely attached to the handle Axes used for driving wedges should have a straight handle Single bit axes need to be heavy enough to 5 pounds to drive plastic wedges into the trees being felled The back of the ax poll should be smooth have rounded edges and be free of burrs to minimize damage to wedges Pulaskis should never be used to drive wedges Always remove branches underbrush overhead obstruc tions or debris that might interfere with limbing and chopping Do not allow anyone to stand in the immediate area Make sure workers know how far materials may fly Protect all workers against flying chips and other chop ping
9. The most aggressive cutter type It is designed for production timber felling and should be used only by experienced sawyers Square ground chisel End view Figure 3 3 The chisel is the most aggressive cutter type Chisel chain should be used only by experienced sawyers Oregon Maintenance and Safety Manual permission by Blount Inc chain requires a file that fits the square shape of the cutting edge It is more difficult to file than other types of chain No file guide is available Round ground chisel chain may be filed with a round file and file guide All chisel chain dulls very quickly when it is exposed to dirt or dust It is not recommended for brushing or limbing because of the potential for kickback 22 Semichisel figure 3 4 A less aggressive cutter type than chisel A round file is used with a file guide when filing semichisel chain The semichisel cutter is more tolerant of dirt and dust and stays sharp longer than the other cutters Low kickback chain is the most desirable chain for training inexperienced sawyers The chain cuts smoothly and is ideal for cutting brush small diameter material dimensional lumber house logs and other materials that normally aren t cut with chain saws Low kickback chain is available with chipper chisel and semichisel cutters End view Figure 3 4 The semichisel cutter is less aggressive than the chisel cutter will tolerate some dirt and stays sharp longer
10. ack Figure 3 17 Start the saw on firm ground 31 Chapter 3 Chain Saw Use and Maintenance Operational Safety A full wrap handlebar allows cutting from both sides of the tree using the bottom of the bar the part of the bar that can be used aggressively In some situations the ability to cut wood rapidly is critically important for safety Full wrap handlebars are designed to be used by both the left and the right hand The sawyer s thumb should always be wrapped completely around the han dlebar no matter how the saw is turned The thumb and fingers are essential for maintaining control of the chain saw especially during a kickback The grip on the chain saw should be firm but not overly tight Handling e Never operate a chain saw with one hand You do not have control of the saw and increase the risk that you will be injured if the saw kicks back Always grip the saw firmly with both hands Grasp the throttle handle firmly with your dominant hand and grasp the handlebar with your less dominant hand Your fingers must encircle the handlebar with the thumb wrapped underneath Never operate a chain saw with the throttle lock engaged If you do you will not be able to control the saw or the chain speed Make sure your work area is clear of people and ob stacles such as rocks stumps holes or roots that may cause you to stumble or fall Make sure that the saw chain does not contact any material
11. adjusted so that it doesn t hang from the bar but still turns freely e Check the chain brake to make sure it s operating properly Chain Maintenance Chain maintenance is crucial to the performance of any chain saw Before beginning any work assignment follow four basic rules to maintain the saw chain for top performance and safe operation 1 Your chain must be sharp When it is the chain does the work When the chain is dull you do the work making you fatigued and increasing the wear on the bar and chain 2 Your depth gauges must be set correctly The gauges depths and shapes are critical to the saw s perfor mance and your safety 3 Your chain must be correctly tensioned More bar and chain problems are caused by incorrect chain tension than by any other single problem 4 Your chain must be well lubricated Your bar chain and roller tip need a steady supply of oil Otherwise your bar and chain will be subject to excessive wear and damage 2 Chapter 3 Chain Saw Use and Maintenance Several conditions can increase the chain s potential for kickback the risk that the chain might be thrown or broken or the risk of other hazards Look for these con ditions when inspecting your chain saw e Loose chain tension e Incorrect chain angles generally caused by improper filing e Dull chain e Alteration of chain features designed to reduce kick back e Incorrect depth gauge settings genera
12. and chain The oiler provides oil through a small hole in the bar that lines up with the oiler on the power head As oil is pumped through the oil hole the chain carries it around the bar lubricating the top bottom and roller tip During operation debris begins to build up in the chain groove If the groove is not cleaned oil cannot lubricate the entire bar causing excessive wear and damage If the oiler is properly adjusted a full tank of gas will run dry before the oil tank is empty As a general rule a tank of oil should last as long as or longer than a tank of gas Clean and rotate the bar each time you file the chain or at least once a day Be sure to clean the bar after filing the chain because the filings act as an abrasive increas ing the wear on the bar Cleaning Exercise Remove the bar and chain for inspection and cleaning Check the bar for wear Look for uneven rails flared edges cracks and other damage that would require the bar to be repaired or serviced Clean the chain groove and oil holes The proper method for cleaning the chain groove is to start at the tip with the bar tool and clean toward the base moving debris away from the roller tip Be sure that the oil holes are clean The sprocket nose roller tip should spin freely Grease the roller tip Remove and clean the air filter Never use an air hose to blow out the air filter Take care not to damage the filter Gently ta
13. arts of a Chain Saw sh Ja Saw chain Guide bar Bar studs Front and side chain tensioners Chain sprocket Chain brake Clutch Chain catcher 1 2 3 4 5 6 1 8 Starter grip Bumper spikes dogs Handlebar Hand guard Gunning marks Throttle handle Throttle trigger Throttle interlock Choke Air filter cover Air filter Oil and fuel caps Muffler Spark arrester Spark plug Carburetor adjustments On off switch From Chain Safety Manual permission by Stihl Inc 24 filter and fuel filter are clean and that you are using the right fuel mixture Dirty filters or improper fuel mixtures affect the idle speed Newer saws designed to meet the U S Environmental Protection Agency CEPA air quality standards may not have all three adjustments e Mounts or antivibration system Buffers between the engine and the handles that reduce vibrations to the sawyer s hands not shown Guide Bar Maintenance Most guide bar problems develop in the bar rails and are caused by e Incorrect chain tension Lack of lubrication e Improper cutting techniques e Normal wear Look for several rail conditions igure 3 8 when per forming daily maintenance on your saw These conditions can be corrected if they are caught early If they are ignored they will destroy the bar or lead to cutting problems For instance it may not be possible to cut straight with the saw or to match cuts on larger material
14. auges with a depth gauge tool Saw Transportation Saws must be transported in a way that protects them from being damaged from injuring people and from damaging property and equipment Transporting Chain Saws in a Vehicle e Keep the bar and chain covered with a chain guard e Properly secure the chain saw to prevent it from being damaged and to prevent fuel from spilling e Never transport a chain saw or fuel in a vehicle s passenger compartment Transporting Chain Saws by Hand The muffler and power head can reach extremely high temperatures Avoid these areas when carrying a saw that has been used recently e When carrying the saw for short distances set the saw at idle speed and set the chain brake e When carrying the saw farther than from tree to tree or in hazardous conditions such as slippery surfaces or heavy underbrush and in all cases if the saw is carried more than 50 feet the saw shall be shut off and carried in a way that prevents the chain muffler and bumper spikes dogs from contacting your body e When carrying the saw on your shoulder take extra care because of the sharpness of the chain and bumper spikes dogs A long sleeved shirt gloves and a shoul der pad must be worn The bar chain and bumper spikes dogs should be covered preferably with a manufactured bar and chain cover Chain saw chaps can be used to cover the bumper spikes dogs Safe Chain Saw Use The methods to
15. e bar and cutting problems Oregon Maintenance and Safety Manual permission by Blount Inc e The bar shows excessive wear only behind the nose on solid nose bars or behind the sprocket on sprock et nose bars This wear can be caused by heavy use near the nose of the bar such as limbing or by a chain that is too loose You can reduce this wear by periodically turning the bar over If wear becomes extensive you may need to replace the bar 25 Chapter 3 Chain Saw Use and Maintenance e The bar is bent This can be caused by improper cut ting techniques getting the saw pinched or bound in the cut or improper transportation such as carrying a saw loose in the bed of a pickup Some bars can be straightened at a shop that has the proper equipment The condition of the guide bar has as much to do with the performance of your chain saw as the condition of the chain The bar and the chain work together When both are in proper condition the chain saw does the work All you have to do is guide it Chain Tension Remember three basic rules for tensioning a saw chain e Turn the saw off e Wear protective gloves e Wait until the bar and chain have cooled before adjust ing the tension Heat causes the bar and chain to expand when the chain saw is being used If the tension is set while the chain is hot the chain will be too tight when it cools Tension that is set too tight can damage the bar and chain To adj
16. e solid nose and sprocket nose figure 3 7 A sprocket nose bar has a Chapter 3 Chain Saw Use and Maintenance sprocket in the nose to reduce drag and help the chain move freely around the bar Generally a solid nose bar is found on small saws The bar is solid without a sprocket Oil holes Bow bar Figure 3 7 The three most common types of guide bars Oregon Maintenance and Safety Manual permission by Blount Inc Parts of a chain saw e Bar studs Hold the bar and chain sprocket cover in place e Front and side chain tensioner Moves the guide bar to maintain proper tension on the saw chain e Chain sprocket The toothed wheel that drives the saw chain e Chain brake Stops the saw chain if it is activated by the sawyer s hand or by inertia during kickback e Clutcbh Couples the engine to the chain sprocket when the engine is accelerated above idle speed Chain catcher Helps reduce the risk of the saw chain contacting the sawyer if the chain breaks or if the chain is thrown off the bar Starter grip A rubber or plastic handle attached to the starter pull rope 23 Chapter 3 Chain Saw Use and Maintenance Bumper spikes dogs Hold the saw steady against wood Handlebar Used to hold the front of the saw Hand guard Activates the chain brake and prevents the sawyer s hand from contacting the chain Gunning marks Used to determine the planned direction of the tr
17. ee s fall based on the undercut Throttle handle Used to hold the rear of the saw Throttle trigger Controls the speed of the engine Throttle interlock Prevents the throttle from being activated unless it is depressed On off switch Turns the saw on and off Choke Used for starting a cold saw Air filter cover Holds the air filter in place and covers the carburetor Air filter Prevents dirt dust and sawdust from enter ing the carburetor Fuel filter Prevents dirt and other contaminants from entering the saw s carburetor not shown Oil and fuel caps Seal the oil and fuel tanks Muffler Reduces exhaust noise Spark arrester Prevents hot sparks from leaving the muffler Spark plug Ignites fuel in the power head Carburetor adjustments Chain saws have a two stage carburetor that provides fuel to the engine in any position that a saw may be held The carburetor has three adjustments Idle speed sets the speed at which the saw s engine will run by itself Low end speed controls the mixture of air and fuel on the first half of the throttle High end speed controls the mixture of air and fuel on the second half of the throttle The high and low end adjustments should be made by a qualified saw mechanic Improper adjustment can result in poor operation or severely damage the chain saw The idle adjustment may need to be adjusted in the field Before adjusting the idle be sure that the air P
18. electing the proper chain is important to the safe operation of a chain saw Chain Saw Components Saw chain The three most common types of cutter teeth used by the Forest Service are chipper chisel and semichisel Saw chain is made up of several parts that work together and must be maintained properly for maximum performance and safety The cutter is the part of the saw chain that does the cutting The saw chain has left and right hand cutters so that the saw chain will cut evenly through the wood The depth gauge referred to as a raker in some parts of the country determines the depth of the cut figure 3 1 Cutting corner Side plate Depth gauge Gullet Figure 3 1 The depth gauge is the part of the tooth used to set the thickness of the shaving Oregon Maintenance and Safety Manual permission by Blount Inc The three basic types of cutters include Chipper The most versatile cutter type Chipper chain figure 3 2 is the easiest to file and will tolerate the most dirt and dust Chipper chain cuts smoothly and is well suited for many Forest Service chain saw operations 21 Chapter 3 Chain Saw Use and Maintenance End view Figure 3 2 The chipper is the most versatile cutter type Chipper chain is easy to file will tolerate the most dirt and can be used for many types of sawing operations Oregon Maintenance and Safety Manual permission by Blount Inc Chisel figure 3 3
19. he wedge to be driven more easily and sending less of a shock wave up the tree Striking the wedge when the tree is in its backward sway sends a severe shock wave up the tree and can knock out dead branches or tops endangering the sawyer Sawyers should look up for falling material after each blow to the wedge Figure 3 21 A rifled single taper wedge is designed to provide lift during tree fell ing It can be stacked with additional rifled single taper wedges Double taper wedges figure 3 22 are designed to reduce bind They taper equally on both sides from the centerline forcing the wood to move equally in both directions They perform best when used in bucking to prevent the kerf from closing which would cause the guide bar to bind Chapter 3 Chain Saw Use and Maintenance Figure 3 22 Double taper wedges are designed to reduce bind Fuel and Oil Containers Use Forest Service approved containers to transport fuel and oil All lids shall be fully sealed prior to transport Even empty containers are dangerous e If a container is missing a lid or showing signs of a defect such as cracks take it out of service immediately All employees who handle transport or use flammable or combustible liquids shall receive hazard communi cation standards training and be familiar with material safety data sheets e Passengers shall not ride in the enclosed cargo portion of a vehicle hauling flammable or combus
20. led or the material being bucked determines the size of the wedge that will be needed If the wedge is too small it may be ineffective If the wedge is too long it may not be able to do its job without being driven so far into the tree that it contacts the chain Always drive wedges by striking them squarely on the head Drive them carefully to prevent them from flying out of the cut Check wedges daily or before each job Do not use cracked or flawed wedges Wedges that are damaged need to be cleaned up before they are used again Grind wedges to the manufacturer s original shape and angle Wear eye protection and a dust mask Repair any driving tool or remove it from service when its head begins to chip or mushroom Carry wedges in an appropriate belt or other container not in the pockets of clothing Most wedges are made out of plastic or soft metal such as magnesium and come in different sizes Use plastic wedges in both felling and bucking operations to prevent the saw chain from being damaged if it contacts the wedges The two basic types of wedges used in sawing are single and double taper Single taper wedges figure 3 21 are simple inclined planes designed to provide lift during tree felling As the wedge is driven into the back cut the tree hinges on the holding wood redistributing the tree s weight The sawyer must coordinate striking the wedge with the forward sway of the tree allowing t
21. lly too deep e Improper shape of depth gauges rakers after filing e Incorrectly installed chain parts e Loose rivets or cracks and breaks in any part of the chain Chain Filing This section focuses on chain filing with a round file and a clamp on hand held file guide that clamps on the file sometimes called a file holder Using these files is the least complicated least expensive and most efficient way to file saw chain by hand in the field Select a file that is the proper diameter for the saw chain After the saw chain has been hand filed a few times it should be ground on a chain grinder to restore angles that may have changed during hand filing and to grind all cutters to the same length Understanding how a cutter works will help you see why proper chain maintenance is so important The depth gauge rides on the wood and controls the depth at which the cutting corner bites into the wood figure 3 9 The cutting corner and side plate sever the wood fibers across the cross grain The top plate cutting angle chisels out the severed wood fibers lifting them from the kerf Three angles must be maintained when filing or grinding a saw chain figure 3 10 A clamp on file guide maintains these angles The angles may vary on different types of saw chains Figure 3 9 The depth gauge controls the depth at which a tooth s cutting corner bites into the wood Oregon Maintenance and Safety Manual
22. ods Peaveys peaveys and cant hooks come with a duckbill hook that are handy for prying logs up onto blocks to keep the saw is a good all around style Peaveys and cant hooks come from pinching while bucking The cant hook is used with hickory handles that are from 2 to 5 feet long primarily to roll logs Keep the handle free of splinters splits and cracks Keep the point sharp Keep your body balanced when pushing or pulling the pole Grip the handle firmly Do not overstress it Carry the peavey with the point forward grasping it just behind the point of attachment of the hook Secure the hook to the shaft to prevent it from swinging free e Place a guard on the point when the tool is not in use Figure 3 23a Peaveys are used in the woods to pry logs 36
23. p the filter against another surface Don t rub or scrape it Do not clean the filter with saw fuel A damaged air filter can allow dust and debris into the engine causing excessive wear and other problems Follow the manufacturer s recommendations found in the instruction manual for cleaning the air filter and determining whether it needs to be replaced A dirty or plugged air filter reduces the power and performance and may cause other seemingly unrelated problems Check the muffler and spark arrester Replace the screen if it has any holes Remove the spark plug e Check for fouling e The tip of the plug should be beige not black e The plug should be dry e Check the plug weekly when the saw is in frequent use Inspect the power head for loose bolts and damage Chapter 3 Chain Saw Use and Maintenance e Tighten the bolts or repair the power head if needed e Check the handlebars for loose bolts or cracks e Check the bumper spikes dogs for loose or bent bolts e Check the mounts They are the antivibration system Look for cracks in the rubber Excessive movement of the engine or a loose feeling when the saw is held by the handles and shaken indicate that the mounts may be broken or that they need tightening Replace the bar and chain Rotate the bar so it wears evenly e Check for proper alignment of the bar with the bar studs adjuster and oiler e Check the chain tension The chain should be
24. s such as rocks or wire Such contact is a safety hazard and will dull the chain The chain will require filing or it may be damaged in ways that filing cannot correct Cutting with the bottom of the bar pulls the chain saw away from the sawyer Cutting with the top of the bar pushes the saw back at the sawyer Cutting with the bottom of the bar increases efficiency and decreases the sawyer s fatigue 32 Reactive Forces The laws of physics explain that for every action there is an equal and opposite reaction These reactions happen very quickly during chain saw operation and can be dangerous Kickback Kickback is the most powerful reactive force you will encounter while operating a chain saw Kickback can occur while felling limbing bucking or brushing when the upper quadrant of the bar nose contacts a solid object or is pinched figure 3 18 During kickback the bar is forced up and back in an uncontrolled arc toward the sawyer Many factors de termine the severity of the kickback and the arc in cluding chain speed angle of contact condition of the chain and the speed at which the bar contacts the object Ways to avoid kickback e Hold the saw with both hands securely gripping the handle and the handlebar between your thumb and forefinger Be aware of the location of the bar s nose at all times Never let the bar s nose contact another object Never cut with the power head higher than your
25. shoulder Never overreach Pull the saw smoothly out of the cuts This technique will help to reduce kickbacks and fatigue Cut one log at a time Stand to the side of the kickback arc Use caution when entering a partially completed cut Use a properly sharpened and tensioned chain at all times Watch the cut and the log for any movement that may pinch the chain e Use a low kickback chain Chapter 3 Chain Saw Use and Maintenance POTENTIAL KICKBACK SITUATION Figure 3 18 Kickback occurs when the upper quadrant of the bar nose contacts a solid object or is pinched Oregon Maintenance and Safety Manual permission by Blount Inc Pushback Pushback figure 3 19 occurs when the chain on the top of the bar is suddenly stopped by contacting another object or by being pinched The chain drives the saw straight back toward the sawyer Figure 3 19 Pushback occurs when the chain on the top of the bar is suddenly stopped by contacting another object or by being pinched From Chain Safety Manual permission by Stibl Inc Ways to avoid pushback e Only cut with the top of the bar when necessary e Watch the cut and the log for any movement that may pinch the top of the bar e Do not twist the bar when removing it from a boring cut or underbuck Pull In Pull in occurs when the chain on the bottom of the bar is caught or pinched and suddenly stops The chain pulls the saw forward figure 3
26. tible liquids If it is absolutely necessary to carry flammable or combustible liquids with a passenger vehicle a mini mum amount of such cargo shall be secured in a rack on the roof Never transport fuel in the same cargo area with oxi dizers acids or radio equipment Flammable or combustible liquids shall be carried in Forest Service approved containers Such containers shall be clearly labeled to identify the contents Containers shall never be filled more than 90 percent with fuel Fuel vapors need room to expand A chain saw should be fueled only after the saw has cooled com pletely 35 Chapter 3 Chain Saw Use and Maintenance Fueling a Chain Saw Allow the saw to cool for at least 5 minutes before refueling Fill the saw on bare ground or other noncombustible surface Immediately clean up spilled fuel Refuel outdoors and at least 20 feet from any open flame or other sources of ignition Do not start the saw closer than 10 feet from the fueling area Peaveys and Cant Hooks The blacksmith Joseph Figure 3 23b The cant hook has a tow or lip at the lower end Peavey invented the peavey figure 3 23a Both the eens Ennis See Meee ery peavey and the cant hook figure 3 23b use a curved metal hook on the end of a straight handle to roll or skid logs A peavey has a sharp pointed spike at the lower end while a cant hook has a tow or lip Most Peaveys are used almost exclusively in the wo
27. ust the chain tension on a solid nose bar Loosen the bar nuts on the side of the saw Pull the nose of the bar up and keep the nose up as you adjust the tension Turn your saw s adjustment screw until the bottoms of the lowest tie straps and cutters just touch the bottom of the bar Still holding the nose up tighten the rear bar nut then the front bar nut While wearing gloves pull the chain along the top of the bar several times from the engine to the tip The chain should feel snug but pull freely 26 The tension must be tighter on a sprocket nose bar than on a solid nose bar To adjust the tension on a sprocket nose bar Loosen the bar nuts on the side of the saw Pull the nose of the bar up and keep the nose up as you adjust the tension Turn your saw s adjustment screw until the bottoms of the lowest tie straps and cutters solidly contact the bottom of the bar While wearing gloves pull the chain along the top of the bar several times from the engine to the tip The chain should feel snug but still pull freely Daily Saw Maintenance As the chain goes around the bar it wears the bar and the chain Because the bar is made of softer metal the bar wears more than the chain Generally one rail will wear more than the other causing the saw to cut at an angle if the bar and the chain are not maintained properly Chain saws have a chain oiler to minimize wear and prolong the life of the bar
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