Windings Resistance Values; Meggering; Special Procedures Engine; Readjusting Rpm - Mastervolt WHISPER 3,5 User Manual

5.3.3 Winding resistant values
If after establishing and correcting any fault on the
capacitor and diodes output is still low when separately
excited, then the main rotor, stator and exciter stator
winding resistance should be checked as the fault must
be in one of these windings. The respective leads must
be disconnected before taking the readings.
Resistance values should be within 10% of the values
given in the table below:
Resistance
• Resistance both main stator windings
in series
• Resistance both rotor windings
• Resistance battery charger winding
• Resistance exciter stator winding

5.3.4 Meggering

One can try to measure resistance between the housing
and the windings by a multimeter which should read
infinity.
When readings indicate infinity but a fault is suspected
one can do a high voltage resistance test (MEGGERING)
This procedure should be carried out by an expert
5.4

SPECIAL PROCEDURES ENGINE

5.4.1 Setting the RPM
RPM is set by the manufacturer and should not need
readjustment! However a very slight offset after running
in could occur. RPM can be measured by a frequency
meter. Before readjustment check any other explanation
for the wrong speed. Engine speed is set at the factory
at nominal 3600 (60 Hz) RPM. A RPM drop of 5% at full
load is acceptable. Therefore a no load setting should be
USA / WHISPER 3,5 / April 2004
60Hz
0.71 Ohm
2.1 Ohm
0.13 Ohm
2 Ohm
Fig. 16: Setting assembly.
at ± 3750 RPM = 62.5 Hz. Under no circumstances
should the RPM under full load be below 3540 RPM =
59 Hz. When no cause can be found for a wrong speed,
the setting can be adjusted:
It is very important to identify the correct setting assem-
bly (refer to fig. 16).
The screw is to be locked in position with the lock-nut.

5.4.2 Tightening torques

Valve clearance Refer to Maintenance, §4.2.3.
Cylinder head screws M10x1.5 51.9 to 56.8 Nm; 5.3 to
5.8 kgf-m; 38.3 to 42.0 ft-lbs.
Rocker arm bracket mounting M8x1.25 23.5 to 27.4 Nm;
2.4 to 2.8 kgf-m; 17.4 to 20.3 ft-lbs.

5.4.3 measuring exhaust backpressure

The exhaust system must be of adequate size -
1 5/8"/ 40 mm no more-no less - and maximal length
(refer to installation manual). This is true for all
generators, but specially for the Whisper 3,5, because
this small engine has a small gasflow that easily can be
blocked by a water trap in the exhaust system. When any
doubt; backpressure has to be measured. An easy way
to measure for back-pressure is to use a water column.
Fig. 17: Measuring exhaust backpressure
A water column can be made visible in a plastic tube
along a yardstick and fitting the end to a hose connection
to fit in the adaptor on the injection bent after removing
the exhaust temperature switch.
The bent A hanging down should not be to short helping
to damp the pulsating effect of the gas discharge, that is
characteristic for a one cylinder engine. The water
column should be no more than 24 inches (60 cm.) of
water (0,87 PSI - 0,06 bar)
TROUBLE SHOOTING
60
24
27