TROUBLE SHOOTING
32 Copyright © 2009 Mastervolt / December 2009 / WHISPER 3.5 / EN
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
3000 (50 Hz) RPM. A RPM drop of 5% at full load is
acceptable. Therefore a no load setting should be at ±
3150 RPM = 52.5 Hz. Under no circumstances should the
RPM be under full load below 2940 RPM = 49 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 assembly (refer to fig. 16).The screw is to be
locked in position with the lock-nut.
Figure 16: Setting assembly
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.
Rocker arm bracket mounting: M8 x 1,25:
23.5 to 27,4 Nm; 2,4 to 2,8 kgf-m.
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 gas flow 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. 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)
Figure 17: Measuring exhaust backpressure
0
4
To Next Page
Loading...
