Why does my Mercury/Mariner 25 MARATHON engine misfire at high RPM?
Engine misfiring at high RPM can be caused by a defective coil or a defective switch box. You should check or replace the defective coil and/or switch box to resolve this issue.
What to do if my Mercury/Mariner Outboard Motor engine starts hard when cold?
If your engine is hard to start when cold, it could be due to a defective trigger assembly or a defective ignition switch box. Check the trigger assembly and ignition switch box to resolve this.
What causes no spark or weak spark on both cylinders of my Mercury/Mariner 25 MARATHON Outboard Motor?
If there's no spark, the cause may be the trigger, stator, ignition switch box, or a bad ground connection from the switch box to the block. If there's a weak spark, it could be the stator. Check the trigger, stator, ignition switch box, or ground connection. If the spark is weak, focus on checking the stator.
What causes my Mercury/Mariner 25 MARATHON to start hard when hot?
A defective switch box or trigger can cause your engine to start hard when it is hot. Check or replace the defective switch box or trigger.
What causes timing fluctuations in my Mercury/Mariner 25 MARATHON?
Timing fluctuations can be caused by a shorted trigger wire or a defective ignition switch box. Check the trigger wire or replace the ignition switch box to fix this.
What to do if my Mercury/Mariner Outboard Motor engine misfires at low RPM but runs smooth at high RPM?
If your engine misfires at low RPM but runs smoothly at high RPM, it could be due to a defective harness or loose connections, a defective switch box, or a defective stator. Check the harness and connections, switch box, and stator.
Why won't the timing advance on my Mercury/Mariner 25 MARATHON Outboard Motor?
If the timing will not advance, it is likely due to a defective switch box. Replace the switch box to resolve this.
What causes no spark or weak spark on one cylinder of my Mercury/Mariner Outboard Motor?
If you have no spark or a weak spark on one cylinder, the cause could be the ignition switch box or the coil. Check the ignition switch box or coil.
What to do if my Mercury/Mariner 25 MARATHON Outboard Motor occasionally misfires?
If your engine occasionally misfires, replace the standard spark plug with an inductor plug. Also, check for a bad ground connection from the switch box to the block. Replace the spark plug with an inductor plug and check the ground connection.
General| Brand | Mercury/Mariner |
|---|---|
| Model | 25 MARATHON |
| Category | Outboard Motor |
| Language | English |
Details specific technical data and parameters for the outboard motor models.
Outlines routine inspection and maintenance tasks for the outboard motor.
Covers the procedures and safety for installing the outboard motor onto a boat.
Details the ignition system components, specifications, and troubleshooting for engine starting.
Explains the battery, charging system, and starting system components and maintenance.
Presents various wiring diagrams for different models and systems of the outboard.
Details specifications, adjustments, and components of the carburetor and fuel pump system.
Explains exhaust emissions, standards, and control methods for marine engines.
Lists specifications for engine components like bore, stroke, pistons, and crankshaft.
Outlines the steps for safely removing the powerhead from the engine assembly.
Provides instructions for reassembling the powerhead after disassembly or repair.
Details the components and assembly of the clamp bracket used for mounting the outboard.
Explains the assembly and components of the swivel bracket, critical for steering.
Lists specifications for the gear housing, including ratio, capacity, and lubricant.
Outlines the steps for safely removing the gear housing from the outboard.
Provides instructions for reassembling the gear housing after disassembly or repair.
Lists specifications for the jet drive system, including impeller clearance.
Explains how to set the correct outboard mounting height to prevent cavitation or drag.
Details the procedure for adjusting the shift link rod to ensure proper gear engagement and safety.
Details the components and assembly of the throttle and shift linkage for tiller handle models.
Covers the removal, disassembly, reassembly, and installation of the control platform.
Covers the removal, installation, and securing of the horizontal shift shaft.
Details the components and assembly of the tiller handle, including various models and colors.
Outlines the steps for removing and disassembling the tiller handle assembly.
Details the components and linkage for throttle and shift operations on side shift models.
Covers the reassembly and installation of the throttle cam and control lever for side shift models.
Provides specifications for the manual starting system, including rope length.
Details the components and assembly of the manual starter system.
Outlines the removal and installation procedures for the rewind starter assembly.
Provides instructions for replacing the starter rope on the rewind starter assembly.
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