Operating Instructions
below 25 psi (172 kPa) at 1200 rpm or 30 psi (207 kPa)
Engine Temperature
at 2100 rpm and normal operating pressure should be
Normal engine coolant temperature is 160-185F (71-
higher.
85C).
Crankcase
Warm- Up
If the engine crankcase was refilled. stop the engine
Run the engine at part throttle and no load for
after normal operating temperature has been reached,
approximately five minutes. allowing it to warm-up
allow the oil to drain (approximately 20 minutes) back
before applying a load.
into the crankcase and check the oil level. Add oil, if
necessary, to bring it to the proper level on the
If the unit is operating in a closed room, start the
dipstick.
room ventilating fan or open the windows, as weather
conditions permit, so ample air is available for the
Use only the heavy duty lubricating oil specified under
engine.
Lubricating Oil Specifcations.
Clutch
Inspection
Do not engage the clutch (with a sintered iron clutch
While the engine is running at operating temperature,
plate) at engine speeds over 850 rpm. A clutch with an
check for coolant. fuel or lubricating oil leaks. Tighten
asbestos or vegetable fiber material clutch plate must
the line connections where necessary to stop leaks.
not be engaged at speeds over 1000 rpm.
Operating Oil Pressure at 180 F (82 C)*
Position
Position
Marine Gear
† Test
T e s t Pressure
Marine Gear
† Test
Test
Pressure
rpm
kPa
kPa
rpm
psi
psi
Neutral and
MG-506 (except
Neutral
M C - 5 1 4 (less
138-448
600
20-65
280-315
1930-2170
than 4:1 ratio)
1.5:1 and 2:1 ratios,
Engaged
600
Neutral
1800
45-92
310-634
Neutral and
1447-1619
Engaged
(shallow case)
600
210-235
Engaged
1800
300-320
2067-2205
228-237
Engaged
1800
1571-1633
Min.
C'ulslng
270
1861
Cruising
Min.
1481
215
MG-506 (only
Neutral and
MG-514 (4:1 and
Neutral
600
241-448
35-65
1.5:1 and 2:1 ratios)
Engaged
600
330-365
2274-2515
greater ratio)
Neutral
1800
50-85
379-586
Neutral and
( d e e p case)
187-215
600
1289-1481
Engaged
1800
Engaged
350-370
2412-2550
1800
193-220
Engaged
1330-1516
Cruising
Min.
Min.
335
2308
Cruising
185
1275
600
45-85
241-483
MG-509
310-586
Neutral
600
35-70
Neutral
MG-521
1800
75-100
517-689
Neutral
1800
345-586
50-85
Neutral
1289-1481
600
187-215
600
180-215
1241-1481
Engaged
Engaged
1800
193-220
1800
188-220
Engaged
1330-1516
Engaged
1296-1516
Cruising
Min.
1137
Min.
1137
165
Cruising
165
MG-512
Neutral
600
45-70
310-483
MG-527
Neutral
600
45-85
310-586
Neutral
1800
60-90
414-621
Neutral
1800
448-689
65-100
Engaged
600
185-215
1275-1481
600
Engaged
1241-1481
180-215
1800
Engaged
195-220
1344-1516
1800
Engaged
188-220
1296-1516
Cruising
Min.
185
1275
Cruising
Min.
1137
165
Neutral
MG-513
600
70-110
483-758
Neutral
1800
90-130
621-896
600
230-270
Engaged
1585-1861
1800
Engaged
240-280
1654-1930
Cruising
Min.
234
1612
* Sump or heat exchanger inlet 210 F (99 C) maximum Normal operating range desired 140-180 F (60-82 C) minimum
continuous duty
† Sump or heat exchanger inlet 225F (107C) maximum intermittent permissable in pleasure craft.
TABLE 2 -Twin Disc Marine Gear Operating Conditions
Page 56
