Mariner 30 JET 40 (4 CYL) Service Manual page 71

Timing/Synchronizing &
Adjusting
Specifications
Full Throttle RPM Range
Idle RPM (in Forward Gear)
Maximum Timing
Throttle Primary Pick Up
Throttle Secondary Pick Up
Recommended Spark Plug
Firing Order
Special Tools
Part No.
91-99379
91-59339
91-63998A1
Timing Adjustments
STATIC TIMING (OUTBOARD NOT RUNNING)
IMPORTANT: On ELECTRIC START MODELS,
outboard battery MUST BE FULLY CHARGED
when making timing checks. MANUAL START
MODELS MUST BE RUNNING in order to make
any timing checks.
ELECTRIC START MODELS
1. Remove top cowling.
2. Remove spark plug leads from spark plugs and
remove spark plugs from outboard.
NOTE: Removing spark plugs eliminates possibility
of outboard accidentally starting and also allows
starter motor to turn outboards over faster thus pro-
viding more accurate timing readings.
90-814676R1 DECEMBER 1996
5000-5500
600-700
(3 - 10 ATDC)
30 BTDC
@ 5500 RPM
2 BTDC - 2 ATDC
30 BTDC
NGK BUHW-2
1-3-2-4
Description
Timing Light
Tachometer
Spark Gap Tester
3. Install SPARK GAP TESTER (91-63998A1) be-
tween No. 1 (TOP) spark plug lead and engine
ground.
4. Connect TIMING LIGHT (91-99379) to No. 1
(TOP) spark plug lead.
IMPORTANT: If carburetors were previously re-
moved, it is recommended that they be synchro-
nized prior to making any timing adjustments.
Refer to SECTION 3 for proper synchronization
procedures.
THROTTLE PRIMARY PICK UP ADJUSTMENT
1. Engage electric starter and advance throttle/
spark arm until specified primary pickup timing
mark aligns with "V" notch in timing pointer win-
dow of flywheel cover.
a
a - "V" Notch
b - Window
2. Hold throttle/spark arm steady and turn IDLE
RPM SCREW until it just touches its stop. WHile
holding throttle/spark arm against IDLE RPM
SCREW STOP, verify specified primary pick up
timing mark is still aligned with "V" notch. If timing
mark has changed, adjust IDLE RPM SCREW to
realign timing mark.
ELECTRICAL AND IGNITION - 2C-1
b
54658