This do-it-yourself repair and service manual by Seloc covers 2005 to 2011 Mercury 2.5 to 350 HP 4-Stroke Outboard Motors with 1 through 4 cylinders and V6 or V8 motors, including those with Jet Drives. The manual is designed to walk users through the service and repair process, performing routine maintenance, troubleshooting issue and engaging in basic repair tasks. The manual covers a wide range of topics from general information about your Seloc motor to fuel systems, lubrication, powerheads and more. The comprehensive guide includes everything a Mercury outboard owner should know and is a great resource for DIY mechanics, professionals, students and more.
Models included in this manual:
- Mercury 2.5, 3.5 Hp
- Mercury 4, 5, 6 Hp
- Mercury 15, 20 Hp 351cc
- Mercury 25 Hp 498cc
- Mercury 25, 25J, 30 Hp 526cc
- Mercury 30, 40 Hp 747cc
- Mercury 40, 40J, 50, 60 Hp 996cc
- Mercury 75, 90 Hp 1596cc Carb, EFI
- Mercury 115 Hp 1741cc
- Mercury 75, 80, 90, 100, 115 Hp 1732cc
- Mercury 135, 150, 175, 200 Hp 1732cc Verado
- Mercury 200, 225, 250, 275, 300, 350 Hp 1598cc Verado
Book Excerpt: 2005-2011 Mercury 2.5-350 HP, 1-4 Cylinder, V6, V8 4-Stroke Outboards Repair Manual
MERCURY/MARINER SMALL-MOTOR EFI | 30/40 HP (747C) and 40/40J/50/60 HP (996CC) MOTORS (See Figure 70)
CYLINDER HEAD OVERHAUL
The small-motor Mercury/Mariner EFI system is found on the 30/40 hp (747cc) and 40/40J/50/60 hp (996cc) motors. It is generally similar to the Yamaha system with only a few component differences.
For most 30-60 hp inline 3-cyl and 4-cylinder motors (except the 25/30 hp Nissan/Tohatsu based model), Mercury/Mariner opted to install their own fuel injection system as Yamaha had not yet marketed those powerheads with an EFI system of their own.
The Mercury/Mariner EFI 4-stroke system is a tuned multi-port, method of fuel injection which is very similar to the Yamaha system differing mostly in the fuel hose routing/flow of the high pressure circuit (specifically the use of a fuel distribution manifold assembly and non re-circulating fuel at the injectors).
Like the Yamaha system the injectors are mounted to the intake manifold, however, they are NOT mounted to a fuel rail assembly as they are connected by fuel lines to the fuel distribution manifold from which fuel makes a one way only trip to the injectors.
Also like the Yamaha system, the injectors are found between the throttle air valve (throttle body) and the cylinder head intake valves.
Like most marine fuel injection systems made during this timeframe, the 4-stroke EFI system does not contain an oxygen sensor, therefore all engine fuel mapping decisions are based upon a combination of factors including engine speed from the pulsar coil (which provides crankshaft position information and is referred to in Mercury service literature as the crankshaft position sensor of CPS), throttle opening from the throttle position sensor (TPS) and intake air from the manifold air temperature (MAT) and manifold air pressure (MAP) sensors.
In this way the ECM keeps track of just how much air is entering the engine (between the TPS and the temperature/pressure of the air) and can adjust air/fuel mixture ratios to suit operating conditions.
The lack of an oxygen sensor makes this form of injection open-loop only (meaning the ECM receives no feedback on the combustion process).
(See Figures 124 and 125)
As usual, don't remove the valve stem seals unless you are planning on replacing them.
- Remove the cylinder head from the powerhead assembly, as detailed in this section.
- Remove the oil pump from the cylinder head, as detailed in the Lubrication & Cooling section.
- Remove the 5 bolts securing the rocker shaft and rocker arm retainers/tensioners. The clips at either end of the shaft and at center are known as retainers, while the other two (on either side of the center retainer) are normally called tensioners (because they should have an overload spring mounted under them).
If they are reused the retainers and tensioners must not only be installed in the same positions, but also facing with the same orientation. In some cases the tensioners may have arrows stamped on their surface, which must be faced toward the sprocket end of the cylinder head.
- Remove the rocker arm shaft along with the 8 rocker arm assemblies. However, whenever possible, keep the rockers and retainers assembled to the shaft in order to prevent accidentally mixing parts during cleaning and inspection.
When working on the assembly during cleaning either tag all parts as they are removed or keep them arranged carefully to prevent mix-up during assembly.
Subject: 2005, 2006, 2007, 2008, 2009, 2010, 2011 Mercury 4-stroke 1-4 cylinder, V6 and V8 outboard motor service, maintenance, repair. ISBN-10: 0893300845 | ISBN-13: 9780893300845| Seloc 1422