28
April 2004 / WHISPER 20 ULTRA / USA
TROUBLE SHOOTING
The flexible lead connected to the diode should be dis-
connected at the terminal end, and the forward and
reverse resistance checked. A healthy diode will indicate
a very high resistance (infinity) in the reverse direction,
and a low resistance in the forward direction. A faulty
diode will give a full deflection reading in both directions
with the test meter on the 10,000 ohms scale, or an
infinity reading in both directions. Replace the diode.
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 Whisper 20 ULTRA
60Hz-240V
• Resistance both main stator windings
0.15 Ohm
in series
• Resistance both rotor windings
3,90 Ohm
• Resistance exciter stator winding
0,36 Ohm
5.3.4 Meggering
One can try to measure resistance between the housing and
the windings by a multimeter which should read infinitely.
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 1800 RPM (60 Hz). A RPM drop of 5% at full
load is acceptable. Therefore a no load setting should be
at + 1875 RPM = 62.5 Hz.
Under no circumstances the RPM under full load should
be below 1770 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. 18).
The screw is to be locked in position with the lock-nut.
5.4.2. Adjusting valve clearance and retightening the
cylinder head bolts.
Both procedures has to be executed with a cold engine.
When both procedures are executed be sure to retighten
the cylinder head bolts before adjusting the valve clea-
rance.
When retightening the cylinderhead bolts, drain the coo-
lant by removing the drain plug (ref. to fig. 2).
Loosen the bolts slightly, remove the rocker assembly
(the rocker arms, shaft, and stays) and then retighten the
bolts to the specified torque in the numerical order
illustrated (ref. to fig. 19).
Tightening torque cylinder head bolt: 118 ± 5 Nm
Rocker stay tightening torque: long bolts 15 ± 2 Nm
short bolts 12 ± 1 Nm
Front
engine
The clearance of both valves intake and exhaust should
be 0.25 mm in cold condition. Set the piston of the first
cylinder to be adjusted to top dead centre (T.D.C.) of
compression stroke.
The T.D.C. of compression stroke can be found by
aligning the T.D.C. mark -0- on the crankshaft pulley with
the mark on the gear case (ref. to fig. 20).
First align the T.D.C. mark for the No. 1 cylinder. Confirm
that the valves do not move up or down when the
Fig. 18.
2= adjustment screw RPM
Fig. 19.
2
DIODE
Fig. 17.
