The 1986 Briggs and Stratton 5 HP Motor is a classic small engine designed for various applications including lawn mowers, tillers, and other outdoor power equipment. This parts manual provides comprehensive information on engine components, part numbers, assembly diagrams, maintenance procedures, and troubleshooting guidance for the 5 horsepower vertical and horizontal shaft models manufactured in 1986.
Technical specifications for the 1986 Briggs and Stratton 5 HP engine models.
| Specification | Details |
|---|---|
| Engine Type | 4-cycle, single cylinder, air-cooled |
| Bore x Stroke | 2.437" x 1.750" (61.9mm x 44.5mm) |
| Displacement | 8.18 cu in (134 cc) |
| Compression Ratio | 6.0:1 |
| Ignition System | Solid State Magnetron |
| Fuel Tank Capacity | 1.0 gallon (3.8 liters) |
| Oil Capacity | 20 oz (0.6 liters) |
| Governor Type | Mechanical |
| Carburetor | Pulsa-Jet or Flo-Jet |
| Starting System | Recoil starter |
Major engine components and their corresponding part numbers.
NOTE! Always verify part numbers with your engine model code before ordering.
Detailed breakdown of cylinder head, piston, rings, and valves.
TORQUE SPECIFICATIONS: Cylinder head bolts: 165-180 in-lbs, Spark plug: 180-210 in-lbs
Crankshaft, connecting rod, bearings, and related components.
| Component | Part Number | Description |
|---|---|---|
| Crankshaft | 291617 | Forged steel, 1" diameter shaft |
| Connecting Rod | 291617 | Forged steel with bearing |
| Main Bearings | 690318 | Ball bearings, both ends |
| Seal Kit | 491588 | Crankshaft seals and gaskets |
| Flywheel | 692748 | Cast aluminum with magnets |
| Key | 701314 | Woodruff key 1/4" x 1-1/4" |
Carburetor components, adjustment procedures, and service information.
WARNING! Gasoline is flammable - work in well-ventilated area away from ignition sources.
Magnetron ignition system components and service procedures.
TESTING: Spark should jump 1/4" gap on tester. No spark indicates faulty coil or flywheel.
Fuel tank, lines, filter, and carburetor fuel delivery system.
MAINTENANCE: Clean fuel tank annually, replace fuel lines every 2 years.
Splash lubrication system components and oil specifications.
| Component | Service Interval | Specification |
|---|---|---|
| Engine Oil | Every 25 hours or season | SAE 30 detergent oil |
| Oil Change | Annually | 20 oz capacity |
| Dipstick | Check each use | Fill to FULL mark |
| Oil Drain | With oil change | Remove drain plug or tip engine |
| Oil Seal | As needed | Part # 491588 |
Air cooling system components and maintenance requirements.
CAUTION! Never operate engine without cooling shrouds in place.
Recommended maintenance intervals for optimal performance.
| Service Item | Frequency | Procedure |
|---|---|---|
| Oil Change | Every 25 hours or season | Drain and refill with SAE 30 |
| Air Filter | Every 25 hours | Clean or replace foam element |
| Spark Plug | Every 100 hours | Clean and gap or replace |
| Fuel System | Annually | Clean tank and carburetor |
| Valve Clearance | Every 300 hours | Set intake: 0.005-0.007", exhaust: 0.009-0.011" |
| Compression Test | As needed | Should be 60+ PSI |
Common problems and solutions for the 5 HP Briggs engine.
| Symptom | Possible Cause | Corrective Action |
|---|---|---|
| Engine won't start | No spark, bad fuel, choke | Check spark, fresh gas, proper choke setting |
| Hard starting | Dirty carburetor, bad plug | Clean carburetor, replace spark plug |
| Loss of power | Dirty air filter, governor | Clean filter, check governor springs |
| Overheating | Dirty cooling fins | Clean fins and shrouding |
| Oil consumption | Worn rings, bad seals | Check compression, replace seals |
| Engine surges | Fuel delivery, governor | Clean carburetor, adjust governor |
Service Support: Briggs & Stratton dealer locator: 1-800-233-3723
Parts Ordering: Use engine model and type numbers for correct parts