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XP20HP REV: XP20HP_rev12072022 5800 Ontario Mills Pkwy This manual provides information regarding the Ontario, CA 91764 USA operation and maintenance of these products. We www.duromaxpower.com have made every effort to ensure the accuracy of the Call our Customer Care Team Toll Free 8-5pm PST Mon-Fri information in this manual.
CONTENTS Introduction Introduction ........................6 General Safety Procedures .................... 8 Unit and Purchase Information................... 12 Engine Components ..................... 13 Package Contents ......................14 Engine Setup Adding Oil ........................16 Adding Gasoline ......................17 High Altitude Operation ....................18 Starting the Engine Check the Oil .........................
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CONTENTS Specifications Specifications ......................... 43 Adjustment and Torque Value Specifications ............44 Engine Diagrams ......................45 Wiring Diagram ......................47 Troubleshooting ......................51 Warranty .......................... 54 Customer Service ......................58 For more information and resources on this model scan the QR code below to link to our website product information page.
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DUROMAX The DuroMax Way is more than just a brand, it is our understanding and appreciation of just how important power can be to someone without it… DUROMAX FOR HOME DUROMAX FOR WORK DUROMAX FOR PLAY Electricity in our home not...
INTRODUCTION DuroMax Power Equipment is headquartered in Ontario, California and is the industry’s leader in Dual Fuel portable generator technology. In addition to a full assortment of portable generators ranging from digital inverters to large 15,000-watt portable standby units, their product line includes pressure washers, engines, pumps, and accessories.
GENERAL SAFETY PROCEDURES SAFETY ALERT SYMBOL The safety alert symbol is used with one of the safety words (DANGER, WARNING, or CAUTION) to alert you of hazards. Please pay attention to these hazard notices both in this manual and on the engine. Please familiarize yourself with the following safety symbols and words: ●...
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WARNING: This engine may emit highly flammable and explosive gasoline vapors, which can cause severe burns or even death. A nearby open flame can lead to an explosion even if not directly in contact with gasoline. ● Do not operate near an open flame. ●...
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GENERAL SAFETY PROCEDURES (CONTINUED) In addition to the above safety notices, please familiarize yourself with the safety and hazard markings on the engine. 1.5”...
UNIT AND PURCHASE INFORMATION Serial Number Serial number The serial number is located on the engine block, to the left of the oil fill. Serial number format The serial number will be shown in two parts. The engine model, followed by the serial number. Engine Model: _____________________________________________ Serial Number: _____________________________________________ STAPLE RECEIPT HERE...
ENGINE COMPONENTS 1. Air Filter 3. Fuel Tank 5. Recoil Handle 6. Muffler 7. Engine Shaft 2. Carburetor 8. Oil Fill 4. Recoil Starter 9. Oil Drain Plug 1. Air Filter - A removable, cleanable, oiled, element that cleans the air going into the engine. 2.
PACKAGE CONTENTS Your engine comes with the items listed below. Please check to see that all of the following items are included with your engine. Spark Plug Wrench Oil Funnel Used in spark plug Used to add oil to the engine maintenance, inspection, and without messy spills.
. You must add the proper amount of oil before operating the engine for the first time. This amount is equal to the oil capacity of the engine crankcase: Model Number XP20HP Engine Oil Capacity 40.5 fl. oz (1.2 L) WARNING: Do not apply engine oils with additives or 2-stroke gasoline engine oils;...
Slowly add unleaded gasoline to the fuel tank. Be careful not to overfill. Replace fuel cap and wipe up any spilled gasoline with a dry cloth. Model Number XP20HP Gas Tank Capacity 1.79 US gal. (6.78 L) DANGER DO NOT OVERFILL 1.5”...
Operation at altitudes below 3,000 feet (900 meters) with a modified carburetor may cause the engine to overheat and result in serious engine damage. Note: Jet kits available for purchase upon request, please contact us at 844-DUROMAX to set up your parts order.
STARTING THE ENGINE If this is not your first time using the engine there are still steps you should take to prepare it for operation each time you use it. IMPORTANT: At this point you should be familiar with the procedures described in the first portion of this section entitled “ENGINE SETUP”...
(see “Adding Oil” portion of the “Maintenance” section). Be sure to replace the cap when finished checking oil. Model Number XP20HP Engine Oil Capacity 40.5 fl. oz (1.2 L)
Step 2 - Check the Fuel Level Check fuel level Before starting your engine, check to see that there is sufficient gasoline in the fuel tank. The gasoline level should always be under the red fuel level indicator located on the bottom of the fuel filter cup.
STARTING THE ENGINE (CONTINUED) Starting the Engine Move fuel valve to ON The gas valve is located above the carburetor bowl. Move the gasoline fuel valve lever all the way to the right-hand position to allow gasoline to flow to the engine carburetor. Move choke lever to ON The choke lever is located above the gas valve.
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Pull the recoil start handle Pull the recoil handle slowly until resistance is felt, then quickly pull the recoil handle until fully extended. Continue this step until the engine starts as needed. CAUTION: Release the recoil handle only after the cord has retracted.
MAINTENANCE AND CARE Proper maintenance and storage of your engine is essential to ensure trouble free use of your Engine when you need it. By following the maintenance and care requirements, you can keep your engine running smooth and efficient for years to come.
MAINTENANCE AND CARE Proper routine maintenance of your engine is essential for safe, economical, and trouble-free operation. It will also help reduce air pollution. WARNING: Improper maintenance, or failure to correct a problem before operation, can cause a malfunction in which you can be seriously injured or killed. Always follow the inspection, maintenance recommendations, and schedules in this instruction manual.
Break-In Period As the best practice for any new combustion motor it’s recommended to perform the break in procedure as follows: ● Run the engine for the first 6-8 hours on conventional oil, then change the oil. After the break-in period synthetic oil may be used. ●...
(see “Adding Oil” portion of the “Maintenance” section). The oil will be visible in the oil fill spout when full. Be sure to replace the cap when finished checking oil. Model Number XP20HP Engine Oil Capacity 40.5 fl. oz (1.2 L)
Changing the Oil CAUTION: Worn out or dirty oil does not cool the engine properly and can lead to catastrophic engine damage. In addition to regular oil changes, it is necessary to drain the oil from the crankcase if it has become contaminated with water or dirt.
Remove old filter element Remove the wing nut on top of the air filter element and slide filter element off center bolt. This filter is paper and is not reusable. Please call 1-844-DUROMAX to order a replacement filter for your engine.
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Replace new filter element Slide new filter element over center bolt, and replace wing nut. Tighten wing nut hand tight to keep filter in place. Replace filter cover Replace plastic air filter cover over the air filter base. Secure filter cover Fasten the air filter cover with the air filter cover wing nut and tighten about hand tight.
MAINTENANCE AND CARE (CONTINUED) Spark Plug Maintenance The spark plug is important for proper engine operation. SPARK PLUG A good spark plug should be intact, free of deposits, and CONSULT MANUAL properly gapped. BEFORE REMOVING CAUTION: Improper maintenance may cause reduced fuel economy, misfires, trouble starting, or damage to the spark plug threads.
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Measure plug gap Measure the plug gap with a gauge. The gap should be 0.7-0.8 mm (0.028-0.031 in). Clean and re-gap If you are re-using the spark plug, use a wire brush to clean any dirt from around the spark plug base and then re-gap the spark plug.
MAINTENANCE AND CARE (CONTINUED) Emptying the Gas Tank If you have been using gasoline in your engine, before storing your engine for extended periods of time you should drain your engine fuel tank of gasoline. CAUTION: Do not store fuel from one season to another.
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Turn fuel valve ON and drain Turn the fuel valve to “ON” and allow gasoline to drain into the container until the gas tank is empty. Shut fuel valve OFF Once the gasoline is fully drained, move the fuel valve back to the “OFF”...
MAINTENANCE AND CARE (CONTINUED) Storing the Engine for Same Day Use Run the engine Allow the engine to run for 3-5 minutes. Turn engine switch to OFF Flip the switch down to the “OFF” position to shut the engine off. Store engine After the engine shuts off and cools, then you can store the engine.
Storing the Engine for Use Within 30 Days Run the engine Allow the engine to run for 3-5 minutes. Shut fuel valve OFF and run dry Shut the fuel valve “OFF” and allow engine to run until it stalls out. Turn the engine switch OFF Flip the switch down to the “OFF”...
MAINTENANCE AND CARE (CONTINUED) Storing the Engine for Longer Than 30 Days Run the engine Allow the engine to run for 3-5 minutes. Shut fuel valve OFF and run dry Shut the fuel valve “OFF” and allow engine to run until it stalls out.
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Remove spark plug Remove spark plug as shown in “Spark Plug Maintenance” on page 32. Add oil to cylinder Add 2 tablespoons of 10W-30 motor oil directly into the spark plug hole, and pull the recoil to lubricate cylinder. After lubricating cylinder reinstall the spark plug as shown in “Spark Plug Maintenance”...
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SPECIFICATIONS A quick reference to useful information on your new DuroMax engine, please see this section for more details on this engine’s specifications.
SPECIFICATIONS Displacement 500cc Fuel Type ≥87 octane, ≤10% ethanol, unleaded gasoline Dry Weight 77 lbs Maximum Torque 22.87 ft. lb @ 2500 rpm Compression Ratio 8.5:1 Bore X Stroke 94 mm x 72 mm Engine Oil Capacity 40.5 oz. (1.2 L) Fuel Tank Capacity 1.79 gal.
TROUBLESHOOTING Mode Description Solution Engine switch is “OFF” Set engine switch to “ON” Fuel valve is “OFF” Turn fuel valve to “ON” Choke is open Close the choke Engine is out of fuel Add fuel Engine will not start Fuel is old or contaminated Change fuel Spark plug is dirty Clean spark plug...
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WARRANTY This section of the manual is to help you understand your warranty.
OEM parts. Warranty Limitations DuroMax Power Equipment does not claim or hold any obligation to loss of time, freight charges, use of product, or any incidental damages from the use of this product. THIS WARRANTY IS IN LIEU OF ALL OTHER WARRANTIES, EXPRESSED OR IMPLIED.
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As the small off-road engine owner, you should be aware that the DuroMax Power Equipment may deny you warranty coverage if your small off-road engine or a part has failed due to abuse, neglect, or improper maintenance or unapproved modifications.
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The use of any non-exempted add-on or modified parts will be grounds for disallowing a warranty claim made in accordance with this Article. DuroMax Power Equipment will not be liable under this Article to warrant failures of warranted parts caused by the use of an add-on or modified part.
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17. Canister Mounting Brackets 18. Carburetor Purge Port Connector * Note: As they relate to the evaporative emission control system. DuroMax Power Equipment will furnish with each new engine written instructions for the maintenance and use of the engine by the owner...
CUSTOMER SERVICE DuroMax Power Equipment is committed to ensuring that our products perform when they need to. Our generators are your lifeline in the event of an emergency. Should you have any problems, please contact our customer service department: DUROMAX POWER EQUIPMENT...
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5800 Ontario Mills Parkway Ontario, CA 91764 United States 844-DUROMAX REV: XP20HP_rev12072022...