Air-cooled Gasoline Engine Instruction Manual

This series features single-cylinder, 4-stroke, contactless transistor ignition, side-valve, forced air-cooled gasoline engines, with compact structure, reliable performance, easy maintenance and economical use. They are ideal power matches for agricultural water pumps, threshers, generator sets and various agricultural/construction machinery.

As our products are continuously improved, there may be slight discrepancies between the manual and the actual product.

I.Overview

Our general-purpose gasoline engine is a single-cylinder, side-valve, 4-stroke air-cooled unit, widely compatible and well-received by users.Proper use and regular maintenance are essential for reliable operation and long service life. Please read this manual carefully to master operation and maintenance methods for optimal performance.

II.Technical Specification

III. Pre-operation Preparation

1. Check Engine Oil Level

Make sure the engine is stopped. Remove the oil dipstick and check whether the oil level is within the standard range.If the oil level is too low, add proper engine oil through the filler port to the specified height.

2. Check Fuel Level

Open the fuel tank cap and check the fuel. Add 92# gasoline as required, up to the red baffle inside the filter. Never mix gasoline with engine oil or use impure fuel.

3. Check the Air Filter

The air filter is of dry type with paper and foam filter elements. Remove the air filter cover for inspection and check if the element is clean. Clean the element if contaminated by dirt, wash it by gentle rubbing, wring it out repeatedly, and reinstall it after fully drained.

IV. Engine Starting and Stopping

1. Engine Starting

Turn on the fuel switch, loosen the drain screw at the bottom of the carburetor until fuel flows out, then tighten the screw to prevent oil leakage. Close the choke and adjust the throttle to the proper position. Pull the starter handle gently first, then pull firmly when resistance appears to start the engine.

After starting the engine, run it at idle for 1–3 minutes to check smooth operation and abnormal noise. Fully open the choke and adjust the throttle to the required speed. The starting operation is completed.

2. Engine Stopping

Adjust the throttle to a proper position to keep the engine running at the minimum stable speed. Close the choke and turn the stop switch to the off position, then the engine will shut down.The starter assembly of general gasoline engines is equipped with a stop switch; simply turn the switch to the OFF position to stop the engine.

V. Regular Maintenance Items

1. Daily Maintenance

• Inspect the air filter element and remove debris to keep it clean.
• Check all fastener bolts and ensure no looseness.
• Verify that the lubricant level is within the specified range.

2. Maintenance Every 25 Working Hours

The air filter element must be cleaned after every 25 working hours, following the cleaning method specified in Item 3 of Chapter 3.

3. Maintenance Every 50 Working Hours

After every 50 working hours, remove carbon deposits from the spark plug, check and adjust the electrode gap to 0.6–0.7mm, and clean dirt between cooling fins.Replace the lubricating oil: loosen the oil drain bolt, tilt the engine slightly to drain the old oil completely. Add clean oil for flushing, tighten the drain bolt after the residual oil flows out, then fill fresh engine oil from the oil filler port up to the specified level.

4. Maintenance Every 100 Working Hours

After every 100 working hours, clean the fuel tank and fuel filter screen. Open the fuel tank cap and take out the filter screen, then clean it gently with a soft brush. Remove the fuel tank, clean the interior to remove attached dirt and moisture. After reinstalling the tank, place the filter screen properly at the f iller inlet, then fill with new fuel up to the red reference line. (See Item 2 of Chapter 3)

5. Biennial Maintenance

Check the fuel hose for aging, hardening and cracks. Replace the hose if damaged. Fasten the connectors after replacement and check for fuel leakage.

• When operating in dusty conditions, perform maintenance more frequently.
• Unless you have the proper tools and mechanical expertise, these maintenance items must be performed by a qualified service technician.

VI. Troubleshooting

Hard Starting

Insufficient Power

Unstable Operation

Sudden Stalling

Engine Overheating

Abnormal Noise in Gasoline Engine Cover

VII. Maintenance Before Long-term Shutdown

If the engine will be out of service for a long time, perform maintenance before storage:

• Remove the fuel tank and drain all fuel, clean dirt and water inside the tank to keep the inner cavity clean.
• Turn on the fuel cock, loosen the drain plug at the bottom to drain residual fuel from the carburetor, then refit the plug.
• Loosen the drain bolt at the bottom of the crankcase, drain all engine oil, then tighten the bolt.
• Wipe off oil stains and dust on the outer surface with clean cotton yarn, and clear dirt between cooling fins.
• Store the engine in a clean and well-ventilated place after cleaning.