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| Home / Engines / Briggs and Stratton Engines / Briggs and Stratton 31R777 |
Briggs and Stratton 31R777 Problems
| Engine Model: Briggs and Stratton 31R777 |
| Engine Type: 4-cycle single cylinder OHV vertical shaft gasoline engine |
| Total Displacement: 30.6 cu.in (501 cc) |
| Rated Engine Power: 15.5 Hp (11.5 kW) at 3600 rpm |
| Fuel System: Float type carburetor with fixed main jet |
| Engine hard to start or will not start |
Gas tank is empty - Fill fuel up.
Incorrect fuel grade - Use quality gasoline.
There is air in the fuel system - Bleed the system.
Spark plug wiring connection is damaged - Check the spark plug wire connection, repair or replace.
Defective spark plug - Change spark plug as required.
Plugged fuel filter - Install new filter.
Brake pedal not depressed - Press the brake pedal.
Carburetor not adjusted - Adjust according to instructions.
Engine has low compression - Check cylinder block and replace defective parts.
Improperly adjusted or worn throttle cable - Replace cable or adjust properly.
| Engine runs roughly |
Cooling fins are blocked - Need to wash or clean.
Ignition system malfunction - Test ignition and replace failed parts.
Choke cable is stuck or defective - Replace or service the cable.
Plugged air filter - Replace or service air filter.
Fuel pump is faulty or clogged - Clean or install new fuel pump.
| Engine starts and stalls immediately |
Spark plug is faulty - Change spark plug.
Carburetor is dirty or faulty - Carburetor needs to be replaced or cleaned.
Defective ignition coil - Change ignition coil as required.
Broken or bad valve springs - Replace valve springs.
Valves sticking - Valves must be cleaned.
| Engine keeps overheating |
Engine oil level low - Checking oil level and add if necessary.
Excessive engine load - Reduce the load.
Cooling fins are clogged - Wash or clean as required.
Carburetor is running lean - Adjust carburetor correctly.
Ignition timing is improper - Set the ignition timing properly.
Improper valve setting - Set the valves correctly.
| Engine noises or knocks |
Stale fuel - Use proper fuel.
Excessive engine load - Reduce the load.
Low engine oil level - Checking oil level and add if necessary.
Incorrect low idle setting - Adjustment required.
Fuel pump is faulty or clogged - Check fuel pump and replace if necessary.
Crankshaft or main bearings wear - Replace crankshaft or bearings.
Valve clearance is wrong - Check and adjust.
Cylinder bore or piston rings are worn - Change defective components.
| Engine lacks power |
Clogged or improperly adjusted carburetor - Service or properly adjust carburetor.
Clogged air filter - Replace or service air filter.
Fuel pump is damaged or dirty - Inspect fuel pump and change as required.
Ignition failure - Check ignition system and replace faulty parts.
Damaged cylinder-head gasket - Cylinder-head gasket replacement required.
Valves are burned or stuck - Change or service valves.
Worn or damaged push rod - Push rod needs to be changed.
Cylinder block parts are damaged - Defective components need to be replaced.
Clogged oil filter (if equipped) - Service or change oil filter.
| High fuel consumption |
Throttle is not fully open - Change or adjust throttle cable.
Improper carburetor main jet adjustment - Adjust it correctly.
Spark plug is defective or loose - Re-tighten or replace spark plug.
Stuck, burned, or worn valves - Change or clean valves.
Worn sleeve, rings, or piston - Replace faulty components as required.
Improper valve clearance - Adjust to proper valve clearance.
| Excessive oil consumption |
Damaged seals or gaskets - Worn parts need to be replaced.
Valve guides or stems are damaged - Valves must be replaced.
Piston rings are stuck or worn - Piston rings need to be replaced.
Scored cylinder liner or piston - Inspect piston and liner, fit new components as necessary.
Blocked breather pipe or hose - Clean or change.
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