________________________________________________________________________________________
Briggs and Stratton 31H777 Problems
| Engine Model: Briggs and Stratton 31H777 |
| Engine Type: 4-cycle single cylinder OHV vertical shaft gasoline engine |
| Total Displacement: 30.6 cu.in (502 cc) |
| Rated Engine Power: 18 Hp (13.3 kW) at 3600 rpm |
| Fuel System: Float type carburetor with fixed main jet |
| Engine won't start or hard to start |
No gasoline in tank - Fill it up.
Wrong grade of gasoline - Change gasoline.
Dirt and debris in fuel system - Remove debris and dirt.
Defective wiring connection of spark plug - Inspect spark plug wiring connection, change or repair.
Spark plug is faulty - Change spark plug.
Clogged fuel filter - Install new filter.
Safety contact for brake pedal defective - Install new part.
Carburetor is clogged - Clean the carburetor.
Low engine compression - Inspect cylinder block and change defective components.
Damaged or incorrectly adjusted choke cable - Replace cable or adjust correctly.
Air intake screen is blocked - Wash or clean as required.
Ignition system failure - Test ignition and replace failed parts.
Choke cable is faulty or stuck - Service or change the cable.
Dirty air filter element - Replace or service air filter.
Clogged or defective fuel pump - Service or replace fuel pump.
| Engine starts and stops immediately |
Spark plug is faulty - Change spark plug.
Carburetor is faulty or dirty - Service or replace carburetor.
Ignition coil is faulty - Replace ignition coil as necessary.
Loose or broken valve springs - Install new valve springs.
Valves are stuck - Valves need to be cleaned.
Not enough engine oil - Fill the crankcase with engine oil.
Engine overloaded - Load reducing is recommended.
Air intake grill is clogged - Need to clean or wash.
Carburetor fuel mixture is too lean - Adjust carburetor correctly.
Improper ignition timing - Set the ignition timing correctly.
Valve setting is wrong - Adjust valves as required.
| Abnormal engine noise or knocking |
Low octane fuel - Change gasoline.
Engine overloaded - Load reducing is recommended.
Insufficient engine oil - Fill up the oil to required level.
Too low idle RPM - Correct idle adjustment.
Dirty or damaged fuel pump - Test fuel pump and replace if necessary.
Worn crankshaft or main bearings - Worn parts replacement required.
Valve clearance is wrong - Adjust to proper valve clearance.
Worn piston rings or cylinder bore - Change faulty parts.
Carburetor is clogged or incorrectly adjusted - Clean or properly adjust carburetor.
Air filter element is plugged - Replace or service air filter.
Clogged or defective fuel pump - Test fuel pump and replace if necessary.
Ignition system problems - Test ignition and replace failed parts.
Cylinder head gasket is defective - Install new cylinder head gasket.
Burned or stuck valves - Change or clean valves.
Worn or defective push rod - Push rod needs to be changed.
Cylinder block components are faulty - Change defective parts.
Oil filter is dirty (if equipped) - Service or replace oil filter.
| Engine uses too much fuel |
Choke didn't open fully - Adjust or change choke cable.
Incorrect carburetor main jet adjustment - Adjust the carburetor main jet properly.
Spark plug is loose or faulty - Re-tighten or change the spark plug.
Worn, stuck, or burned valves - Clean or change valves.
Piston, sleeve, or rings are damaged - Change faulty parts.
Valve clearance is wrong - Adjust to proper valve clearance.
| Engine using too much oil |
Worn gaskets or seals - New components need to be installed.
Valve stems and guides are worn - Valves replacement required.
Piston rings are defective or worn - Replace piston rings.
Cylinder liner or piston is damaged - Inspect liner and piston, replace as necessary.
Blocked breather hose or pipe - Service or replace.
________________________________________________________________________________________
________________________________________________________________________________________
| Engines Technical Specifications |
| Lawn and Garden Tractors Technical Specs |
| Farm Tractors Technical Specifications |
