1986 Onan Generator Manual

The 1986 Onan Generator is a reliable power generation unit designed for various applications including residential backup power, construction sites, and recreational use. This manual covers models from the 1986 production year featuring gasoline and diesel engines, electric start capability, automatic voltage regulation, circuit breaker protection, hour meter, fuel gauge, and comprehensive maintenance requirements. Below are key sections for safety, operation, maintenance, troubleshooting, and specifications.

1. Safety Precautions 2. Generator Overview 3. Installation Requirements 4. Starting Procedures 5. Operating Instructions 6. Maintenance Schedule 7. Technical Specifications 8. Fuel System 9. Electrical System 10. Storage Procedures 11. Troubleshooting Guide

Safety Precautions

Critical safety information for proper generator operation and maintenance.

HazardPrecaution
Carbon MonoxideOperate outdoors only; never in enclosed spaces
Electrical ShockKeep dry; use grounded outlets; avoid wet conditions
Fire HazardKeep away from flammable materials; no smoking near unit
Hot SurfacesAllow cooling before servicing; wear protective gloves
Moving PartsKeep hands clear during operation; secure loose clothing
Fuel HandlingRefuel when cool; use approved containers only
Battery SafetyDisconnect battery before maintenance; avoid sparks
Exhaust FumesEnsure proper ventilation; direct exhaust away from occupied areas

Generator Overview

Key components and control panel features of the 1986 Onan Generator.

  1. Control Panel: Includes start/stop switch, circuit breakers, voltage meter, hour meter
  2. Engine: 4-cycle air-cooled engine with overhead valves
  3. Alternator: Brushless design with automatic voltage regulation
  4. Fuel System: Integrated fuel pump and carburetor with sediment bowl
  5. Cooling System: Forced air cooling with flywheel fan
  6. Battery: 12V DC for electric start models

WARNING! Always perform pre-operation inspection before starting generator.

Installation Requirements

Proper installation guidelines for safe and efficient operation.

  1. Location: Level, well-ventilated area with minimum 3 feet clearance on all sides
  2. Foundation: Concrete pad or other stable, level surface
  3. Electrical Connections: Use proper gauge wiring for load requirements
  4. Grounding: Connect to approved grounding rod per local codes
  5. Weather Protection: Install weatherproof enclosure if exposed to elements
  6. Transfer Switch: Required for home backup power applications

CAUTION! Installation must comply with all local electrical and building codes.

Starting Procedures

Step-by-step instructions for starting the generator.

  1. Pre-Start Check: Verify oil level, fuel level, and battery charge
  2. Electrical Load: Ensure all loads are disconnected before starting
  3. Fuel Valve: Turn fuel valve to ON position
  4. Choke: Set choke to CLOSED position for cold starts
  5. Start Switch: Turn to START position; release when engine starts
  6. Warm-up: Allow 2-3 minutes of no-load operation
  7. Choke Adjustment: Gradually open choke as engine warms
  8. Load Application: Connect loads one at a time, monitoring voltage

NOTE: For electric start models, ensure battery is fully charged.

Operating Instructions

Proper operation procedures and monitoring requirements.

Maintenance Schedule

Recommended maintenance intervals and procedures.

IntervalMaintenance Task
Before Each UseCheck oil level, fuel level, air cleaner, loose parts
8 Hours/WeeklyClean air filter, check battery terminals
50 Hours/MonthlyChange oil, inspect spark plug, check valves
100 Hours/6 MonthsReplace air filter, fuel filter, check compression
200 Hours/AnnualComplete tune-up, decarbonize, inspect brushes
500 HoursMajor overhaul, replace wear components

Technical Specifications

Fuel System

Fuel system components and maintenance requirements.

  1. Fuel Tank: Check for rust and sediment accumulation
  2. Fuel Pump: Mechanical diaphragm type; inspect for leaks
  3. Carburetor: Clean jets and passages regularly
  4. Fuel Filter: Replace every 100 hours or when clogged
  5. Fuel Lines: Inspect for cracks and deterioration
  6. Sediment Bowl: Clean and reseal during oil changes

WARNING! Use fresh fuel only; stale fuel can damage engine components.

Electrical System

Electrical components and testing procedures.

ComponentFunctionTesting
Starter MotorElectric startingCheck amp draw, brush wear
AlternatorAC power generationOutput voltage under load
Voltage RegulatorMaintains stable voltageAdjust per service manual
Circuit BreakersOverload protectionTest trip function
BatteryStarting powerSpecific gravity, voltage
Control BoardOperation controlContinuity and function tests

Storage Procedures

Proper storage preparation for extended non-use periods.

  1. Fuel System: Add fuel stabilizer and run for 10 minutes
  2. Oil: Change oil and filter before storage
  3. Battery: Disconnect and store fully charged
  4. Spark Plug: Remove and add oil to cylinder; reinstall
  5. Exterior: Clean thoroughly and apply protective coating
  6. Cover: Use breathable waterproof cover
  7. Location: Store in dry, rodent-free environment

NOTE: Exercise generator monthly during extended storage.

Troubleshooting Guide

ProblemPossible CauseSolution
Engine won't startNo fuel, bad spark, dead batteryCheck fuel, spark plug, battery charge
No power outputBreaker tripped, brush wornReset breaker, inspect/replace brushes
Low voltageEngine speed, regulator faultAdjust governor, test regulator
OverheatingDirty cooling fins, low oilClean cooling system, check oil level
Excessive vibrationMounting loose, imbalanceTighten mounts, check alignment
Fuel leakageCracked lines, loose fittingsReplace lines, tighten connections
Battery not chargingFaulty alternator, bad connectionsTest alternator output, clean terminals

Service Contact: Certified Onan service centers only

Parts: Genuine Onan parts recommended for all replacements

1986 Onan Generator Manual © - All Rights Reserved 2025