OPERATOR’S MANUAL UT10517 / 18 in. 42cc Chain Saw UT10518 / 18 in. 46cc Chain Saw UT10520 / 20 in. 46cc Chain Saw Your chain saw has been engineered and manufactured to Homelite’s high standard for dependability, ease of operation, and operator safety. When properly cared for, it will give you years of rugged, trouble-free performance. WARNING: To reduce the risk of injury, the user must read and understand the operator’s manual before using this product. Thank you for buying a Homelite product.
table of contents Introduction...................................................................................................................................................................... 2 General Safety Rules..................................................................................................................................................... 3-4 Specific Safety Rules..............................................................................................................
general safety rules WARNING: Read and understand all instructions. Failure to follow all instructions listed below, may result in electric shock, fire and/or serious personal injury. READ ALL INSTRUCTIONS Heavy protective clothing may increase operator fatigue, which could lead to heat stroke. During weather that is hot and humid, heavy work should be scheduled for early morning or late afternoon hours when temperatures are cooler.
general safety rules Use only the replacement guide bars and low kickback chains specified for the saw. ■ Do not adapt the powerhead to a bow guide or use it to power any attachments or devices not listed for the saw. ■ The gas powered saw (or electrically powered saw) is classified by CSA as a Class 1C (or Class 2C) saw. It is intended for infrequent use by homeowners, cottagers, and campers, and for such general applications as clearing, pruning, cutting firewood, etc.
symbols Some of the following symbols may be used on this product. Please study them and learn their meaning. Proper interpretation of these symbols will allow you to operate the product better and safer. SYMBOL NAME DESIGNATION/EXPLANATION Safety Alert Precautions that involve your safety. Read The Operator’s Manual To reduce the risk of injury, user must read and understand operator’s manual before using this product.
symbols The following signal words and meanings are intended to explain the levels of risk associated with this product. SYMBOL SIGNAL MEANING DANGER: Indicates an imminently hazardous situation, which, if not avoided, will result in death or serious injury. WARNING: Indicates a potentially hazardous situation, which, if not avoided, could result in death or serious injury. CAUTION: Indicates a potentially hazardous situation, which, if not avoided, may result in minor or moderate injury.
glossary of terms Bucking The process of cross cutting a felled tree or log into lengths. Chain Brake A device used to stop the saw chain. Chain Saw Powerhead A chain saw without the saw chain and guide bar. Clutch A mechanism for connecting and disconnecting a driven member to and from a rotating source of power. Drive Sprocket or Sprocket The toothed part that drives the saw chain.
features PRODUCT SPECIFICATIONS Bar length: UT10517, UT10518..................................................18 in. UT10520..................................................................20 in. Engine displacement....................................................46cc Chain pitch: UT10517.............................................................. .375 in. UT10518, UT10520.............................................. .325 in. Engine power....................................................2.
features Starter grip Starter/Fan housing Rear handle STOP Ignition Switch Fuel cap Throttle trigger Fig. 1b KNOW YOUR CHAIN SAW LOW KICKBACK SAW CHAIN See Figures 1a - 1b. The safe use of this product requires an understanding of the information on the tool and in this operator’s manual as well as a knowledge of the project you are attempting. Before use of this product, familiarize yourself with all operating features and safety rules.
assembly UNPACKING WARNING: This product has been shipped completely assembled. n Carefully remove the tool and any accessories from the box. Make sure that all items listed in the packing list are included. n Inspect the tool carefully to make sure no breakage or damage occurred during shipping. n Do not discard the packing material until you have carefully inspected and satisfactorily operated the tool. n If any parts are damaged or missing, please call 1-800-242-4672 for assistance.
operation FUEL AND REFUELING OXYGENATED FUELS HANDLING THE FUEL SAFELY Some conventional gasolines are blended with alcohol or an ether compound. These gasolines are collectively referred to as oxygenated fuels. To meet clean air standards, some areas of the United States and Canada use oxygenated fuels to help reduce emissions. If using an oxygenated fuel, make sure it is unleaded and meets the minimum octane rating requirements. Before using an oxygenated fuel, try to confirm the fuel’s contents.
operation FILLING THE fuel TANK See Figure 2. n Clean the surface around the fuel cap to prevent contamination. n Loosen the fuel cap slowly. n Carefully pour the fuel mixture into the tank. Avoid spillage. n Immediately replace the fuel cap and hand tighten. Wipe up any fuel spillage. STOP n Prior to replacing the fuel cap, clean and inspect the o-ring. Fig. 2 Note: It is normal for the engine to emit smoke during and after the first use. ADDING bar and chain OIL See Figure 3.
operation STARTING THE ENGINE See Figures 6 - 11. Starting the product differs depending on whether the engine is cold or warm. IGNITION switch IN THE RUN POSITION WARNING: Keep your body to the left of the chain line. Never straddle the saw or chain, or lean over past the chain line. n Place the chain saw on level ground and ensure that no objects or obstructions are in the immediate vicinity that could come in contact with the bar and chain. Fig.
operation n Pull starter grip until engine runs. Note: Allow the saw to run in this position 15-30 seconds, depending upon the temperature. n Squeeze and release the throttle trigger to return the engine to idle after a total run time of at least 30 seconds. CAUTION: Failure to release partial throttle when chain brake lever is in the brake position will result in serious damage to the unit. Never squeeze and hold the throttle trigger while the chain brake is in the brake position.
operation ADJUSTING IDLE SPEED See Figure 15. n If the engine starts, runs, and accelerates, but will not idle, turn the idle speed screw “T” clockwise to increase idle speed. n If the chain turns at idle, turn the idle speed screw “T” counterclockwise to reduce the idle RPM and stop the chain movement. If the saw chain still moves at idle speed, contact an authorized service center for adjustment and discontinue use until the repair is made. STOP WARNING: THE SAW CHAIN SHOULD NEVER TURN AT IDLE.
operation KICKBACK PRECAUTIONS kickback danger zone See Figures 17 - 18. Rotational kickback occurs when the moving chain contacts an object at the Kickback Danger Zone of the guide bar. The result is a lightning-fast reverse reaction, which kicks the guide bar up and back towards the operator. This reaction can cause loss of control, which can result in serious injury. Fig. 17 PREPARING FOR CUTTING rotational kickback PROPER GRIP ON HANDLES See Figure 19.
operation PROPER CUTTING STANCE See Figure 20. ■n Balance your weight with both feet on solid ground. thumb on underside of handle bar n Keep left arm with elbow locked in a “straight arm” position to withstand any kickback force. chain line straight arm n Keep your body to the left of the chain line. n Keep your thumb on underside of handlebar. WORK AREA PRECAUTIONS See Figure 21. n Cut only wood or materials made from wood; no sheet metal, no plastics, no masonry, no non-wood building materials.
operation FELLING TREES planned line of fall HAZARDOUS CONDITIONS WARNING: Do not fell trees during periods of high wind or heavy precipitation. Wait until the hazardous weather has ended. When felling a tree, it is important that you heed the following warnings to prevent possible serious injury. ■n Do not cut down trees having an extreme lean or large trees with rotten limbs, loose bark, or hollow trunks. Have these trees pushed or dragged down with heavy equipment, then cut them up.
operation n On large diameter trees, stop the back cut before it is deep enough for the tree to either fall or settle back on the stump. Then insert soft wooden or plastic wedges into the cut so they do not touch the chain. Drive wedges in, little by little, to help jack the tree over. n When bucking or felling with a wedge, it may be necessary to remove the SAFE-T-TIP anti-kickback device to allow the bar to be drawn through the cut. After you complete the cut, reinstall the tip immediately.
operation BUCKING WITH A WEDGE See Figure 28. If the wood diameter is large enough for you to insert a soft bucking wedge without touching the chain, you should use the wedge to hold the cut open to prevent pinching. Note: When bucking or felling with a wedge, you may need to remove the SAFE-T-TIP anti-kickback device to allow the bar to be drawn through the cut. After you complete the cut, reinstall the tip. WEDGE BUCKING LOGS UNDER STRESS See Figure 29.
operation UNDERBUCKING Underbucking See Figure 31. Begin on the under side of the log with the top of the saw against the log; exert light pressure upward. During underbucking, the saw will tend to push back at you. Be prepared for this reaction and hold the saw firmly to maintain control. LIMBING AND PRUNING See Figures 32 - 33. n Work slowly, keeping both hands on the saw with a firm grip. Maintain secure footing and balance. Fig. 31 ■n Keep the tree between you and the chain while limbing.
maintenance WARNING: Run Position When servicing, use only identical Homelite replacement parts. Use of any other parts may create a hazard or cause product damage. WARNING: Always wear safety goggles or safety glasses with side shields during power tool operation or when blowing dust. If operation is dusty, also wear a dust mask. Fig. 35 GENERAL MAINTENANCE Avoid using solvents when cleaning plastic parts.
maintenance n Lay out the new saw chain in a loop and straighten any kinks. The cutters should face in the direction of chain rotation. If they face backwards, turn the loop over. BAR STUDS n Place the chain drive links into the bar groove as shown. n Position the chain so there is a loop at the back of the bar. n Hold the chain in position on the bar and place the loop around the sprocket. n Fit the bar flush against the mounting surface so that the bar studs are in the long slot of the bar.
maintenance n Replace the outer guide bar plate ensuring that the bar pin groove is at the bottom with the upper and lower edges angled away from the guide bar. n Replace the clutch cover and bar mounting nuts. n Finger-tighten the bar mounting nuts. The bar must be free to move for tension adjustment. n Remove all slack from the chain by turning the chain tensioning screw clockwise until the chain seats snugly against the bar with the drive links in the bar groove.
maintenance n Retension the chain whenever the flats on the drive links hang out of the bar groove. Note: During normal saw operation, the temperature of the chain increases. The drive links of a correctly tensioned warm chain will hang approximately .050 in. out of the bar groove. The tip of the combination wrench can be used as a guide to help determine the correct warm chain tension. Note: New chains tend to stretch; check the chain tension frequently and tension as required. ≈ .050 in. Fig.
maintenance SHARPENING THE CUTTERS See Figures 50 - 53. Be careful to file all cutters to the specified angles and to the same length, as fast cutting can only be obtained when all cutters are uniform. Cutting Corner Side Plate Top Plate Depth Gauge Rivet Hole WARNING: Heel The saw chain is very sharp. Always wear protective gloves when performing maintenance to the chain to prevent serious personal injury. Toe Gullet Fig. 50 n Tension the chain prior to sharpening.
maintenance TOP PLATE FILING ANGLE MAINTAINING DEPTH GAUGE CLEARANCE See Figure 54. n CORRECT 30° – file holders are marked with guide marks to align file properly to produce correct top plate angle. See Figure 56 - 58. n Maintain the depth gauge at a clearance of .025 in. Use a depth gauge tool for checking the depth gauge clearances. n LESS THAN 30° – for cross cutting. n Every time the chain is filed, check the depth gauge clearance. n MORE THAN 30° – feathered edge dulls quickly.
maintenance MAINTAINING THE GUIDE BAR See Figure 59. CAUTION: Make sure the chain has stopped before you do any work on the saw. LUBRICATING HOLE Every week of use, reverse the guide bar on the saw to distribute the wear for maximum bar life. The bar should be cleaned every day of use and checked for wear and damage. Feathering or burring of the bar rails is a normal process of bar wear. Such faults should be smoothed with a file as soon as they occur.
maintenance CLEANING THE AIR FILTER See Figures 62 - 64. n For access to the air filter and carburetor area, loosen the three screws holding the cylinder cover. cylinder cover screw n Activate chain brake. screws n Lift the front of the cylinder cover past chain brake lever. n Lift the back of the cylinder cover past the handle. n Before removing the air filter from the carburetor, blow or brush as much loose dirt and sawdust from around the carburetor and chamber as possible.
maintenance ADJUSTING THE CARBURETOR See Figures 65 - 67. Before adjusting the carburetor: n Use a brush or compressed air to clean the starter cover vents. air filter n Clean the air filter. Refer to Cleaning the Air Filter in the Maintenance section of this manual. n Allow the engine to warm up prior to adjustment of engine idle speed. Fig. 65 warning: Weather conditions and altitude may affect carburetion. Do not allow bystanders close to the chain saw while adjusting the carburetor.
maintenance CLEANING THE ENGINE See Figures 68 - 69. Clean the cylinder fins and flywheel fins with compressed air or a brush periodically. Dangerous overheating of the engine may occur due to impurities on the cylinder. WARNING clean cylinder fins Never run the saw without all the parts, including the drivecase cover and starter housing, securely in place.
maintenance INSPECTING/CLEANING THE SPARK arrestor screen spark arrestor screen See Figure 72. The muffler is equipped with a spark arrestor screen. A faulty spark arrestor screen can create a fire hazard. Through normal use the screen can become dirty and should be inspected weekly and cleaned as required. Always keep the muffler and spark arrestor on the saw in good condition. WARNING Muffler surfaces are very hot during and after operation of the chain saw.
bar and chain combinations Model No. UT10517 UT10518 UT10520 Length of Bar 18 in. 18 in. 20 in. Guide Bar Part Number 310627001 310628001 310629001 Chain Part Number Drive Links 671258001 62 link 3/8 in. low profile 901430001 72 link 0.325 in. standard 900920027 78 link 0.325 in. standard troubleshooting Problem Possible Cause Solution Engine will not start. [Make sure ignition switch is in the RUN ( l ) position.] No spark. Clean or replace spark plug. Reset spark plug gap.
troubleshooting Problem Bar and chain running hot and smoking. Engine starts and runs, but chain is not rotating. Possible Cause Solution Chain oil tank empty. Oil tank should be filled every time fuel tank is filled. Chain tension is too tight. Tension chain per instructions in Adjusting the Chain Tension in the Maintenance section of this manual. Oiler is not functioning. Run at half throttle 30 to 45 seconds. Stop saw and check for oil dripping from SAFE-T-TIP and guide bar.
WARRANTY LIMITED WARRANTY STATEMENT Homelite Consumer Products, Inc., (“Homelite”) warrants to the original retail purchaser that this HOMELITE brand outdoor product is free from defect in material and workmanship and agrees to repair or replace, at Homelite’s, discretion, any defective product free of charge within these time periods from the date of purchase.
WARRANTY The following California Air Resources Board (CARB) statement only applies to model numbers required to meet the CARB requirements. Homelite consumer products, INC., LIMITED WARRANTY STATEMENT FOR FEDERAL AND CALIFORNIA EMISSION CONTROL SYSTEMS NON-ROAD AND SMALL OFF-ROAD ENGINES YOUR WARRANTY RIGHTS AND OBLIGATIONS The U.S. Environmental Protection Agency (EPA), the California Air Resources Board (CARB), and Homelite Consumer Products, Inc.
warranty EMISSIONS MAINTENANCE SCHEDULE AND WARRANTED PARTS LIST Emissions Parts Inspect Before Each Use Clean Every 5 Hours Replace Every 25 Hours or Yearly Clean Every 25 Hours or Yearly Replace Every 50 Hours AIR FILTER ASSY includes: Filter................................................................... X.............................X SPARK ARRESTOR..............................................................................................................
OPERATOR’S MANUAL UT10517 / 18 in. 42cc Chain Saw UT10518 / 18 in. 46cc Chain Saw UT10520 / 20 in. 46cc Chain Saw WARNING: The engine exhaust from this product contains chemicals known to the State of California to cause cancer, birth defects, or other reproductive harm. CALIFORNIA PROPOSITION 65 SERVICE For parts or service, contact your nearest Homelite authorized service dealer. Be sure to provide all relevant information when you call or visit.