Mariner 100, Service Manual, Page: 60 / 391

2C-1 ELECTRICAL AND IGNITION 90-13645--2 1095
Timing/Synchronizing/
Adjusting (3 Cylinder Models)
Specifications
70, 75 and 80 Models
Serial Number and Above
U.S. B239242
Belgium 9502135
Canada A730007
Full Throttle RPM Range 4750 - 5250
Idle RPM (in “FORWARD” Gear) 650 - 700
Maximum Timing @ 5000 RPM
(@ Cranking Speed)
26 B.T.D.C.
(28 B.T.D.C.)
Idle Timing 0 - 4 B.T.D.C.
Spark Plug NGK BUHW-2
Firing Order 1-3-2
70, 75 and 80 Models
Serial Number and Below
U.S. B239241
Belgium 9502134
Canada A730006
Full Throttle RPM Range 4750 - 5250
Idle RPM (in “FORWARD” Gear) 650 - 700
Maximum Timing @ 5000 RPM
(@ Cranking Speed)
22 B.T.D.C.
(24 B.T.D.C.)
Idle Timing 0 - 4 B.T.D.C.
Spark Plug NGK BUHW-2
Firing Order 1-3-2
90 Models
Full Throttle RPM Range 5000 - 5500
Idle RPM (in “FORWARD” Gear) 650 - 700
Maximum Timing @ 5000 RPM
(@ Cranking Speed)
26 B.T.D.C.
(28 B.T.D.C.)
Idle Timing 0 - 4 B.T.D.C.
Spark Plug NGK BUHW-2
Firing Order 1-3-2
Mariner 75 Marathon/Merc 75XD
Full Throttle RPM Range 4750 - 5250
Idle RPM (in “FORWARD” Gear) 650 - 700
Maximum Timing @ 5000 RPM
(@ Cranking Speed)
16 B.T.D.C.
(18 B.T.D.C.)
Idle Timing 0 - 4 B.T.D.C.
Spark Plug NGK BUHW-2
Firing Order 1-3-2
Special Tools
Part No. Description
*91-58222A1 Dial Indicator Gauge Kit
*91-59339 Service Tachometer
*91-99379 Timing Light
91-63998A1 Spark Gap Tool
* May be obtained locally.
Timing Pointer Adjustment
WARNING
Engine could start when turning flywheel to check
timing pointer alignment. Remove spark plugs
from engine to prevent engine from starting.
1. Install Dial Indicator P/N 91-58222A1 into no. 1
(top) cylinder.
2. Turn flywheel clockwise until no. 1 (top) piston is
at top dead center (TDC). Set Dial Indicator to “0”
(zero).
19062
91-58222A1
3. Turn flywheel counterclockwise until Dial Indica-
tor needle reads approximately 0.550 (13.97mm)
BTDC, then turn flywheel clockwise so that
needle reads 0.491 in. (12.47 mm) BTDC exactly.