Typical Automatic Idle Control System - Briggs & Stratton 86262GS Familiarization & Troubleshooting Manual

Typical Automatic Idle Control
System
Some portable generators may be equipped with an
automatic idle control system. Such a system provides
greatly improved fuel economy by running the engine at
normal governed speed only when electrical loads are
plugged in and turned on.When electrical loads are
disconnected or turned off, reduction to idle speed will
occur.
A typical idle control system consists of:
• A Sensing Transformer
• An Idle Control Circuit Board
• An On-Off switch
• An Idle Control Coil
The sensing transformer and circuit board (Figure 2.81) are
housed in an idle control box located just behind the unit's
receptacle panel.
Figure 2.81 — Idle Control System Components
The on-off switch is usually mounted to the idle control box
as well.
The idle control coil is attached to a bracket on the engine
carburetor. A flapper attaches to the throttle.When the
engine is shut down, the throttle is held against the high
speed side of a throttle stop. During operation at "no-load"
and with the idle control switch set to OFF, the flapper will
be at approximately the "no-load" position (Figure 2.82).
Portable Generator Familiarization & Troubleshooting Guide
Section 2 • Generator Components & Systems
Figure 2.82 — Idle Control Coil And Flapper
To run at high governed speed with the unit loaded and at
no-load, set the idle control switch to OFF.
To operate at idle speed with the electrical load
disconnected and at high governed speed with electrical
loads turned on, set the idle control switch to ON
(Figure 2.83).
Figure 2.83 — Idle Control Switch
Always start the engine with the idle control switch set to
OFF. Set the switch to ON after the engine has stabilized at
governed speed. If the engine is started with the switch at
ON, it may start and then shut down. In some cases, surging
or hunting may occur as the idle control solenoid energizes
and de-energizes.
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