Portable Generator User Manual
MQP20P STANDBY GENERATOR • OPERATION AND PARTS MANUAL — REV. #1 (11/28/11) — PAGE 25
INSPECTION/SETUP
COOLANT (ANTIFREEZE/SUMMER COOLANT)
Perkins recommends antifreeze/summer coolant, for use in 
their engines, which can be purchased in concentrate (and 
mixed with 50% demineralized water) or pre-diluted. See the 
Perkins Engine Owner’s Manual for further details.
The engine coolant capacity is 3.8 quarts (3.6 liters).
OPERATION IN FREEZING WEATHER
When operating in freezing weather, be certain the proper 
amount of antifreeze (Table 10) has been added.
CLEANING THE RADIATOR
The  engine  may  overheat  if  the  radiator  fins  become 
overloaded  with  dust  or  debris.  Periodically  clean  the 
radiator  fins  with  compressed  air.  Cleaning  inside  the 
machine is dangerous, so clean only with the engine turned 
off and the negative battery terminal disconnected.
AIR CLEANER
Periodic cleaning/replacement is necessary. Inspect it in 
accordance with the Perkins Engine Owner’s Manual.
 WARNING
If  adding  coolant/antifreeze  mix  to  the 
radiator, do not remove the radiator cap 
until the unit has completely cooled. The 
possibility of hot coolant exists which can 
cause severe burns.
Table 10. Anti-Freeze Operating Temperatures
Vol % 
Anti-
Freeze
Freezing Point Boiling Point
°C °F °C °F
50 -37 -34 108 226
NOTICE
When the antifreeze is mixed with water, the antifreeze 
mixing ratio must be less than 50%.
FAN BELT TENSION
A  slack  fan  belt  may  contribute  to  overheating,  or  to 
insufficient charging of the battery. Inspect the fan belt for 
damage  and  wear  and  adjust  it  in  accordance  with  the 
Perkins Engine Owner’s Manual.
The fan belt tension is proper if the fan belt bends 10 to 
15  mm  (Figure  12)  when  depressed  with  the  thumb  as 
shown below.
Figure 12. Fan Belt Tension
BATTERY 
This unit is of negative ground. DO NOT connect in reverse. 
Always maintain battery fluid level between the specified 
marks. DO NOT over fill. Battery life will be shortened if 
the fluid level is not properly maintained. Add only distilled 
water when replenishment is necessary.
Check to see whether the battery cables are loose. Poor 
contact may result in poor starting or malfunction. Always 
keep the terminals firmly tightened. Coat the terminals with 
an approved battery terminal treatment compound. Replace 
battery with only recommended type battery.
The  battery  is  sufficiently  charged  if  the  specific  gravity 
of the battery fluid is 1.28 (at 68° F). If the specific gravity 
should fall to 1.245 or lower, the battery is dead and needs 
to be recharged or replaced.
Before charging the battery with an external electric source, 
be sure to disconnect the battery cables.
 CAUTION
NEVER place hands near the belts or fan 
while the generator is running.










