Briggs & Stratton 270962, 271172, CE8069, 276535 Flywheel Identification, Testing Alternator Output

Flywheel Identification

OHV single cylinder flywheels have a single ring of magnets which provide the magnetic field for the various alternator systems, except Model Series 97700, 99700, 121600, 126000 which use the magneto magnet. There are two sizes of flywheel magnets. The size of the magnet determines alternator output.

The following table identifies the magnet size to be used with a specific alternator system. NOTICE: Do not use large-magnet flywheels with AC-only, DC-only, or Dual Circuit Alternators.

•Small Magnet - Approx. 28/32” x 21/32” (22mm x 17mm).

•Large Magnet - Approx. 1-3/32” x 29/32” (28mm x 23mm).

Testing Alternator Output

The following alternator test procedures were developed using the Fluke® Digital Multimeter. When performing alternator tests with the UNI-T® Digital Multimeter, refer to the operating manual supplied with that meter for the proper procedure.

All test values will be the same regardless the meter used.

NOTE: Before testing alternator output, use an accurate tachometer to temporarily adjust the engine speed to the RPM specified in the test instructions.

When testing alternators, perform the tests in the following sequence:

1.Test alternator output.

2.Test diode(s) or regulator-rectifier (if equipped).

.5 Amp DC Only Alternator

The .5 Amp, DC alternator is designed to operate as an integral part of the engine and is separate from the starting and ignition system. It is intended to provide DC charging current for a 12 Volt battery. Contact battery or equipment manufacturer for battery information.

Test Alternator Output

Disconnect charging lead to battery at connector.

1.Insert RED test lead into 10 Amp receptacle in meter.

2.Insert BLACK test lead into COM receptacle in meter.

3.Rotate selector to DC Amps position.

4.Attach RED test clip to output terminal (A, Figure 16).

5.Attach BLACK test clip to charging lead (B) that was disconnected at the connector.

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Figure 16

6.With engine running at 2800 RPM, output should be no less than .5 Amp DC.

7.If low or no output, check stator air gap.

8.If stator air gap is within specification and there is low or no output, replace stator.

3-Amp DC Only Alternator

The DC alternator provides DC current for charging a 12 Volt battery. Current from the alternator is unregulated and is rated at 3 Amps. The output rises from 2 Amps at 2400 RPM to 3 Amps at 3600 RPM.

Test Alternator Output

1.Insert RED test lead (A, Figure 17) into 10 Amp receptacle in meter.

2.Insert BLACK test lead (B) into COM receptacle in meter.

3.Rotate selector to DC Amps position.

4.Attach RED test lead clip to DC output terminal connector (C).

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