This Clymer repair manual covers 1994-1997 Mercury Mariner 2-Stroke Outboard Motors 75HP through 275HP, including Jet Drive models:
Book Excerpt: 1994-1997 Mercury Mariner 75-275 HP 2-Stroke Repair Manual
- 75 HP, 90 HP
- 100 HP, 115 HP, 125 HP, 135 HP
- 150 HP, 150 XR6, 150 Magnum III
- 175 HP
- 200 HP, 200 DFI
- 225 HP, 250 HP, 275 HP
- 65 Jet, 80 Jet, 105 Jet, 140 Jet
SPARK PLUG REPLACEMENT
Improper installation and incorrect application are common causes of poor spark plug performance in outboard motors. The gasket on the plug must be fully compressed against a clean plug seat for heat transfer to take place effectively.
IGNITION AND ELECTRICAL SYSTEMS: NEUTRAL SAFETY SWITCH
If heat transfer cannot take place, the spark plug will overheat and fail. This may also lead to preignition and detonation. Make sure the spark plugs are correctly torqued.
Incorrect application can cause not only spark plug problems, but can also lead to ignition system symptoms or failure from RFI (radio frequency interference).
Most engines with an ECM (electronic contol module) require suppression or inductor spark plugs that reduce the RFI caused by the spark jumping the air gap of the spark plug. Always use the recommended spark plugs.
If the engine does not require inductor or suppression spark plugs, yet ignition interference with onboard accessories is noted, install the recommended inductor or suppression spark plug as recommended in Table 2.
CAUTION: When the spark plug(s) are removed, dirt or other foreign material surrounding the spark plug hole(s) can fall into the cylinder(s). Foreign material inside the cylinders can cause engine damage when the engine is started.
On tiller models, the neutral safety switch is mounted on the engine shift linkage. On remote control models, the neutal safety switch is mounted in the remote control box.
Refer to Chapter 12 for Mercury/Mariner remote control box service procedures. If your boat is equipped with an aftermarket control box, consult with the control box manufacturer for service procedures.
The neutral safety switch is designed to prevent the engine from starting in gear. In other words, the electric starter can only engage when the engine shift linkage is in neutral.
A neutral safety switch should have continuity across its two terminals (or leads) any time the shift linkage is in neutral. The switch should indicate no continuity any time the shift linage is in gear.
Subject: 1994, 1995, 1996, 1997 Mercury Mariner 75-275 HP 2-Stroke service, maintenance, repair. ISBN-10: 0892877073 | ISBN-13: 9780892877072