420cc OHV Horizontal Gas Engine Owner’s Manual WARNING: Read carefully and understand all ASSEMBLY AND OPERATION INSTRUCTIONS before operating. Failure to follow the safety rules and other basic safety precautions may result in serious personal injury.
® Thank you very much for choosing a Powerhorse product! For future reference, please complete the owner’s record below: Serial Number/Lot Date Code: ________________________________ Purchase Date: ____________________________________________ Save the receipt, warranty, and this manual. It is important that you read the entire manual to become familiar with this product before you begin using it. This engine is designed for certain applications only.
Table of Contents Technical Specifications ...................................................................................................................... 4 Important Safety Information ............................................................................................................... 4 Specific Operation Warnings ............................................................................................................... 6 Safety Labels .................................................
Technical Specifications Property Model Displacement Bore Stroke Oil Capacity Net Weight Specification DH420 420cc 3.54 inches 2.60 inches 0.29 gal.(1.1L) 68.89 lbs. Important Safety Information SAFETY REFERENCES The safety alert symbol is used to identify safety information about hazards that can result in personal injury. A signal word (DANGER, WARNING, or CAUTION) is used with the alert symbol to indicate the likelihood and the potential severity of injury.
WARNING WORK AREA SAFETY Inspect the work area before each use. Keep work area clean, dry, free of clutter, and well-lit. Cluttered, wet, or dark work areas can result in injury. Using the engine in confined work areas may put you dangerously close to other cutting tools and rotating parts. Do not allow the engine to come into contact with an electrical source. The engine is not insulated and contact will cause electrical shock.
and perform its intended function. Replace damaged or worn parts immediately. Never operate the engine with a damaged part. Specific Operation Warnings WARNING Gasoline and its vapors are extremely flammable and explosive. Fire or an explosion can cause severe burns or death. When Adding Fuel Turn engine 'off' and let it cool at least 2 minutes before removing the fuel filler cap. Fill the fuel tank outdoors or in a well-ventilated area. Do not overfill the fuel tank.
WARNING Rapid retraction of starter cord (kickback) will pull hand and arm toward engine faster than you can let go. Broken bones, fractures, bruises or sprains could result. When starting engine, pull cord slowly until resistance is felt, then pull rapidly. Direct coupled equipment components such as, but not limited to, blades, impellers, pulleys, sprockets, etc., must be securely attached. WARNING Rotating parts can contact or entangle hands, feet, hair, clothing, or accessories.
Safety Labels Page 8 of 35
Main Engine Parts Reference A Subassembly B Muffler C Spark Plug D Throttle Lever E Recoil Starter F Starting Handle G Fuel Shut-off H Choke Lever I Fuel Filler Cap J Fuel Tank K Oil Dipstick L Drain Plug M Control Box Air Cleaner Page 9 of 35
Before Each Use ⚠WARNING Improperly maintaining this engine, or failure to correct a problem before operation, can cause a malfunction in which you can be seriously hurt or killed. Always perform a pre-operation inspection before each operation, and correct any problem. Pre-Operation Checks For your safety, and to maximize the service life of your equipment, it is very important to take a few moments before you operate the engine to check its condition.
Operating Instructions ⚠WARNING Gasoline and its vapors are extremely flammable and explosive. Fire or explosion can cause severe burns or death. Engines give off carbon monoxide, an odorless colorless, poison gas. Breathing carbon monoxide can cause nausea, fainting or death. Unintentional sparking can result in fire or electric shock. Unintentional start-up can result in entanglement, traumatic amputation, or laceration.
2. To start a cold engine, move the choke lever to the CHOKE position. To restart a warm engine, leave the choke lever in the RUN position. 3. Move the throttle lever away from the MIN. position, about 1/3 of the way toward the MAX. position. 4. Turn the engine switch to the ON position.
5. Operate the starter. Recoil Start Pull the starter grip lightly until you feel resistance, then pull briskly in the direction of the arrow as shown below. Return the starter grip gently. ⚠WARNING Do not allow the starter grip to snap back against the engine. Return it gently to prevent damage to the starter. Electric Starter Turn the key to the START position, and hold it there until the engine starts.
When the engine starts, release the key, allowing it to return to the ON position. ⚠WARNING Using the electric starter for more than 5 seconds at a time will overheat the starter motor and can damage it. 6. If the choke lever has been moved to the CHOKE position to start the engine, gradually move it to the RUN position as the engine warms up. Stopping the Engine To stop the engine in an emergency, simply turn the engine switch to the OFF position. Under normal conditions, use the following procedure.
1. Move the throttle lever to the MIN. position. Some engine applications use a remote-mounted throttle control rather than the engine-mounted throttle lever shown here. 2. Turn the engine switch to the OFF position. 3. Turn the fuel shutoff to the OFF position.
Setting Engine Speed Position the throttle lever for the desired engine speed. Some engine applications use a remote-mounted throttle control rather than the engine-mounted throttle lever shown here. Refer to the instructions provided by the equipment manufacturer. For engine speed recommendations, refer to the instructions provided with the equipment powered by this engine. Maintenance ⚠WARNING All the components used to build this engine must remain in place for proper operation.
When Testing for Spark Use an approved spark plug tester. Maintenance Schedule REGULAR SERVICE PERIOD (3) Perform at every indicated month or operating hour interval, Each Use whichever comes first.
Engine Oil Oil is a major factor affecting performance and service life. Use 4-stroke automotive detergent oil. Recommended Oil Use 4-stroke motor oil that meets or exceeds the requirements for API service category SJ or later (or equivalent). Always check the API service label on the oil container to be sure it includes the letters SJ or later (or equivalent). SAE 10W-30 is recommended for general use.
1. Remove the oil dipstick and wipe with a clean cloth. 2. Insert the oil dipstick into the filler neck without screwing it in. 3. Remove the oil dipstick and check the oil level. Make sure the oil is at the FULL mark on the dipstick. 4. If the oil level is near or below the lower limit mark on the dipstick, fill with the recommended oil. Do not overfill. After adding oil, wait one minute and then recheck the oil level. 5. Replace and tighten the oil dipstick. Fuel Recommendations Unleaded gasoline: U.S.
How to Add Fuel ⚠WARNING Gasoline and its vapors are extremely flammable and explosive. Fire or explosion can cause severe burns or death. For refueling, refer to the manufacturer’s instructions provided with the equipment. See the following for a Powerhorse supplied standard fuel tank refueling instruction 1. With the engine stopped and on a level surface, remove the fuel filler cap and check the fuel level. Refill the tank if the fuel level is low. 2.
⚠CAUTION The manufacturer of the equipment on which this engine is installed specifies the top speed at which the engine will be operated. Do not exceed this speed. How to Replace the Spark Plug If the engine has been running, let it cool before servicing the spark plug. For good performance, the spark plug must be properly gapped and free of deposits. 1. Disconnect the spark plug cap, and remove any dirt from around the spark plug area. 2. Remove the spark plug with a 13/16-inch spark plug wrench. 3.
Severe thermal burns can occur on contact. Combustible debris, such as leaves, grass, brush, etc. can catch fire. 1. Allow muffler, engine cylinder, and fins to cool before touching. 2. Remove accumulated debris from muffler area and cylinder area. 3. Replacement parts must be the same and installed in the same position as the original parts or fire could result.
3. Inspect the air filter. Clean dirty air filter with warm water and mild soap. Allow air filter to dry thoroughly before re-installation 4. Install the air filter assembly onto the carburetor and secure with screw. Note: Do not use pressurized air or solvents to clean the filter. Pressurized air can damage the filter and solvents will dissolve the filter.
Removing Oil The oil must be drained from the Oil Drain Plug. (See figure 2.) 1. 2. 3. 4. Remove the dipstick (C) Please an approved container below the oil drain plug. Remove the Oil drain plug (D) and allow oil to the drain into the approved container. Install Oil drain plug (D) and wrench tighten. How to Service the Fuse-see figure 3 (if applicable) ⚠WARNING Never use a fuse with a rating greater than the one originally equipped with the engine.
Troubleshooting ⚠WARNING Do not crank engine with spark plug removed. Failure Possible Cause Corrective Action If engine is cold, ensure choke lever is set correctly. Add fuel. Set choke lever to open/run position. Remove spark plug and clean it. Check the Out of fuel Engine flooded spacing on the electrode and set the gap to If engine will not start the .correct dimension. See Maintenance Dirty or faulty spark plug/engine fails to product spark Section.
** Engine power will decrease 3.5% for each 1,000 feet (300 meters) above sea level and 1% for each 10°F (5.6°C) above 77°F (25°C). The engine will operate satisfactorily at an angle up to 15°. Refer to the equipment operator’s manual for safe allowable operating limits on slopes. We recommend that you see an authorized service center for all maintenance and service of the engine and engine parts. Use only our genuine parts.
Parts Diagram Page 27 of 35
Parts List Ref Code 1 2 3 4 5 6 Part Description Qty Ref Code 260213 CRANKCASE 1 56 260502 SHROUD 1 93029 BALL BEARING 2 57 91325 11 OIL SEAL 2 58 BOLT M6X12 COVER COMP, CYLINDER HEAD 1 59 PACKING, HEADCOVER 1 1 60 LOCK BOLT 1 1 61 SHROUD ASSY, UPPER 1 PIN, LOCK 1 62 93511 93516 263901 96806 SEAL, GOVERNOR ARM SHAFT SHAFT, GOVERNOR ARM WASHER, GOVERNOR ARM SHAFT 261104 96075 91819 264407 Part Description Qty 1 8 91817 BOLT, DRAIN PLUG 2 63 260402 RUBBER, ST
Ref 37 38 Code Part Description Qty Ref Code Part Description Qty 94403 CLIP, FUEL LINE 7.5 1 92 262603 BRACKET 1 1 CHARGE COIL 1 264001 GOVERNOR ARM 93 97210 39 91822 BOLT, GOVERNOR ARM 1 94 260802 LOCKING FLAPS 4 40 90016 NUT M6 1 95 94409 CLIP, FUEL LINE 9.
Limited Warranty Northern Tool and Equipment Company, Inc. ("We'' or "Us'') warrants to the original purchaser only ("You'' or “Your”) that the Powerhorse product purchased will be free from material defects in both materials and workmanship, normal wear and tear excepted, for a period of two years from date of purchase. The foregoing warranty is valid only if the installation and use of the product is strictly in accordance with product instructions.
U.S EPA AND CALIFORNIA EMISSION CONTROL WARRANTY STATEMENT YOUR WARRANTY RIGHTS AND OBLIGATIONS The California Air Resources Board, The United States Environmental Protection Agency (US EPA) and Northern Tool & Equipment Company, Inc. are pleased to explain the emission control system warranty on your 2016 and later model year small off-road engine. In the United States and California new small off-road engines must be designed built and equipped to meet the State’s stringent antismog standards.
DEFECTS WARRANTY COVERAGE Adopted by the Air Resources Board, Northern Tool & Equipment Company, Inc.
to warrant failures of warranted parts caused by the use of a non-exempted add-on or modified part. (11) The manufacturer issuing the warranty shall provide any documents that describe that manufacturer’s warranty procedures or policies within five working days of request by the Air Resources Board. ENGINE INFORMATION Brand: Powerhorse Engine Family: GCDPS.2121DJ, GCDPS.
(e) Air Injection System: (1) Air pump or pulse valve. (2) Valves affecting distribution of flow. (3) Distribution manifold. (f) Catalyst or Thermal Reactor System: (1) Catalytic converter. (2) Thermal reactor. (3) Exhaust manifold. (g) Particulate Controls: (1) Traps, filters, precipitators, and any other device used to capture particulate emissions. (h) Miscellaneous Items Used in Above Systems: (1) Electronic controls. (2) Vacuum, temperature, and time sensitive valves and switches.
Distributed by: Northern Tool & Equipment Company, Inc. Burnsville, Minnesota 55306 www.northerntool.
