3to 11hp 4-cycle l-head engines - Small Engine Suppliers

CHECKING THE SYSTEM: To check the system,
disconnect the plug and measure the D.C. voltage at the
red wire terminal (diag. 24). Measure the A.C. voltage at
the yellow wire terminal. With the engine running, the
minimum values should be:
3 Amp D.C.
2500 R.P.M. - 8.0 Volts D.C.
3000 R.P.M. - 11.0 Volts D.C.
3600 R.P.M. - 13.0 Volts D.C.
5 Amp A.C.
2500 R.P.M. - 8.0 Volts A.C.
3000 R.P.M. - 11.0 Volts A.C.
3600 R.P.M. - 13.0 Volts A.C.
If the above minimum values are noted, system is okay.
Check for defective lights, wiring or switches. If less than
above values are noted, pull back the protective shrink
tubing from the diode. Using an A.C. voltmeter, check the
voltage going into the diode from alternator, at the lead
on the alternator side of the diode (diag.25).
All Models
With the engine running, the minimum values should read:
2500 R.P.M. - 20.0 Volts A.C.
3000 R.P.M. - 25.0 Volts A.C.
3300 R.P.M. - 26.5 Volts A.C.
3600 R.P.M. - 29.0 Volts A.C.
If low or no voltage is experienced, replace the alternator.
If the alternator puts out the minimum A.C. voltage,
replace the diode.
7 Amp Alternator System Regulator-Rectifier
External to Engine
B + TERMINAL WIRE
A.C.
YELLOW
RED
D.C. VOLTMETER
REGULATOR/RECTIFIER
MUST BE GROUNDED
25
26
CHECKING THE SYSTEM: To check the system,
disconnect the D.C. or B+ wire at the switch end and
measure D.C. voltage between the lead and ground (diag.
26).
With the engine running, minimum values should read:
2500 R.P.M. - 9.0 Volts D.C.
3000 R.P.M. - 11.0 Volts D.C.
3600 R.P.M. - 14.0 Volts D.C.
If the minimum readings are noted, system is okay. Check
for defective ammeter, wiring, etc. If less than the above
readings, disconnect the plug from the regulator-rectifier,
and insert the A.C. voltmeter probes in the two outside
terminals (diag. 27).
With the engine running, minimum values should read:
2500 R.P.M. - 12.0 Volts A.C.
3000 R.P.M. - 14.0 Volts A.C.
3600 R.P.M. - 18.0 Volts A.C.
If the minimum readings are noted, the alternator is okay;
the regulator-rectifier is defective. If less than the above
readings, the alternator is defective. See Chapter 9 for
"Disassembly Procedure".
54
A.C.
27