Generac Power Systems XT-EFI Series

DIAGNOSTIC
REPAIR
MANUAL
PORTABLE GENERATORS
50/60 Hz GC/RS/XC/XG/XP//HL/XT
and XT-EFI Series Portable Generators
60 HZ MODELS: 50 HZ MODELS:
RS5500 XC6500 XG4000 XP4000 XT8000E XG5600E
RS7000E XC6500E XG5600 XP6500E XT8000EFI XG6400E
XC8000E XG6400 XP8000E GC8100
XG6500 XP10000E HL6500E
XG7000E
XG10000E
Important Note: Always use the unit specific Schematics and
Wiring Diagrams for troubleshooting.

Generac Power Systems XT-EFI Series Specifications

General

Brand	Generac Power Systems
Model	XT-EFI Series
Category	Portable Generator
Language	English

Summary

Brushless Capacitor Excitation System

Troubleshooting Brushless AC Output

Guides users through diagnosing AC output problems using flowcharts and specific tests.

Problem 1: Zero or Residual Voltage Output

Outlines diagnostic steps for a generator that produces no or very low output voltage.

Direct Excitation (Brush Type) System

Troubleshooting Brush Type AC Output

Guides users through diagnosing AC output problems for brush type generators.

Problem 5: Zero or Residual Voltage Output

Outlines diagnostic steps for a generator that produces no or very low output voltage.

Problem 6: High or Low Voltage & Frequency

Provides troubleshooting steps for generators with incorrect voltage and frequency output.

Problem 7: VoltageFrequency Droop Under Load

Guides diagnosis for voltage/frequency drops when electrical load is applied.

Problem 8: High Voltage at No-Load

Steps to diagnose generators that output excessively high voltage without load.

AC Diagnostic Tests for Generators

Test 1: Check No-Load Voltage and Frequency

Test 2: Check Main Circuit Breaker

Test 3: Check Receptacle Panel Continuity

Test 4: Fixed ExcitationRotor Amp Draw Test

Test 5: Field Flash Alternator Procedure

Test 6: Check Generator Capacitor

Test 7: Test Brushless DPE Windings

Test 8: Test Brushless Stator Windings

Test 9: Test Brushed Stator Windings

Test 10: Check Load Voltage & Frequency

Test 11: Check Load Watts & Amperage

Test 12: Adjust Voltage Regulator Settings

Procedure to adjust the voltage regulator to achieve the correct output voltage.

EFI Engine Control Diagnostic Tests

EFI Fault Code Diagnostics

Engine Diagnostic Tests and Troubleshooting

Engine Diagnostic Flow Charts

Guides users through diagnosing engine issues using flowcharts and specific tests.

Problem 9: Recoil Cord Will Not Pull

Troubleshooting steps for a generator recoil cord that will not pull.

Problem 10: Engine Starts Hard and Runs Rough

Diagnostic steps for an engine that starts with difficulty and runs unevenly.

Problem 11: Engine Cranks But Will Not Start

Troubleshooting for engines that crank but fail to start, focusing on fuel and spark.

Problem 12: Engine Hunts or Has Erratic Idle

Steps to diagnose and resolve engines that exhibit unstable or fluctuating idle speeds.

Problem 13: Engine Will Not Crank

Diagnostic procedures for engines that fail to crank, checking battery, starter, and switch.

Problem 15: Engine Cranks But Will Not Start

Troubleshooting for engines that crank but fail to start, focusing on fuel, spark, and ignition.

Problem 17: Engine Starts Then Shuts Down

Troubleshooting for engines that start and then immediately shut off, checking oil level and pressure.

Problem 18: Battery Will Not Charge

Steps to diagnose why the generator's battery is not charging, checking charger and circuit.

Test 15: Check Battery and Cables

Test 20: Check Ignition Spark

Tests the engine's ignition system for proper spark generation using a spark tester.

Test 22: Check Carburetion

Test 25: Cylinder Leak DownCompression Test

Test 36: Test Battery Charging Circuit