Troubleshooting Yamaha Inverter Generators - Yamaha EF4500iSE Theory & Diagnostics Manual

Yamaha Generator Theory & Diagnostics Guide

TROUBLESHOOTING YAMAHA INVERTER GENERATORS

This guide has troubleshooting flow charts and information to help the Service Department technician cor-
rectly diagnose electrical output and engine running problems. Many diagnostic procedures are the same for
all Yamaha inverter generators, and differences among generators are noted. However, this guide is meant as
a familiarization tool and should not be substituted for the appropriate service manual. Test specifications vary
from model to model, so these numbers are in Section 3 of this book.
Determining if a Problem is
Generator or Engine Related
One item of importance when troubleshooting a generator is differentiating between an electrical problem with
the generator and a mechanical problem with the engine.
It is important we remember that the generator depends on the engines ability to maintain a specific speed,
for it to provide a constant current output.
Be sure you have not overlooked the possibility that the reason the generator does not have the proper output,
is because the engine has lost it's ability to keep up with the generator's needs.
A typical scenario for this may be that the generator's output is OK with no load or a light load, but the output
decreases or becomes erratic as the load increases. Providing that given load would not normally exceed the
rated output.
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