This repair and service manual covers 1984-1996 Yamaha 2-250 HP outboards 1-4 cylinder, V4 and V6 2- and 4-Stroke models including Jet Drives. ENGINES COVERED:

• 2 hp, 1 cyl. (43cc) 2-stroke 1984-1996, 2 hp, 1 cyl. (50cc) 2-stroke 1995-1996
• 3 hp, 1 cyl. (70cc) 2-stroke 1989, 3 hp, 1 cyl. (70cc) 2-stroke 1990-1996
• 4 hp, 1 cyl. (83cc) 2-stroke 1984-1996, 4 hp, 1 cyl. (103cc) 2-stroke 1996
• 5 hp, 1 cyl. (103cc) 2-stroke 1984-1996
• 6 hp, 2 cyl. (165cc) 2-stroke 1986-1996
• 8 hp, 2 cyl. (165cc) 2-stroke 1984-1996
• 9.9 hp, 2 cyl. (246cc) 2-stroke 1984-1996, 9.9 hp, 2 cyl. (232cc) 4-stroke 1984-1996
• 15 hp, 2 cyl. (246cc) 2-stroke 1984-1996
• 20 hp, 2-cyl. (395cc) 2-stroke 1996, 20 hp, 2 cyl. (430cc) 2-stroke 1996
• 25 hp, 2 cyl. (395cc) 2-stroke 1988-1996, 25 hp, 2 cyl. (430cc) 2-stroke 1990-1996
• 25 hp, 2 cyl. (496cc) 2-stroke 1984-1996, 25 hp, 3 cyl. (496cc) 2-stroke 1996
• 28 Jet, 3 cyl. (698cc) 2-stroke 1990-1996
• 30 hp, 2 cyl. (496cc) 2-stroke 1984-1996, 30 hp, 3 cyl. (496cc) 2-stroke 1987-1996
• 35 Jet, 3 cyl. (698cc) 2-stroke 1987-1996
• 40 hp, 2 cyl. (592cc) 2-stroke 1989-1996, 40 hp, 3 cyl. (698cc) 2-stroke 1984-1996
• 45 hp, 4 cyl. (935cc) 4-stroke 1996
• 48 hp, 2 cyl. (760cc) 2-stroke 1996
• 50 hp, 3 cyl. (698cc) 2-stroke 1984-1996, 50 hp, 3 cyl. (849cc) 2-stroke 1994-1996, 50 hp, 4 cyl. (935cc) 4-stroke 1995-1996
• 55 hp, 2 cyl. (760cc) 2-stroke 1989-1995
• 60 hp, 3 cyl. (849cc) 2-stroke 1991-1996
• 65 Jet, 3 cyl. (1140cc) 2-stroke 1987-1996
• 70 hp, 3 cyl. (849cc) 2-stroke 1984-1996
• 75 hp, 3 cyl. (1140cc) 2-stroke 1994-1996
• 80 hp, 3 cyl. (1140cc) 2-stroke 1994-1996
• 80 Jet, V4 (1730cc) 2-stroke 1987-1996, 85 hp, 3 cyl. (1140cc) 2-stroke 1989-1996
• 90 hp, 3 cyl. (1140cc) 2-stroke 1984-1996
• 105 Jet, V6 (2596cc) 2-stroke 1996
• 115 hp, V4 (1730cc) 2-stroke 1984-1996
• 130 hp, V4 (1730cc) 2-stroke 1988-1996
• 140 hp, V4 (1730cc) 2-stroke 1984-1996, 140 Jet, V6 (2596cc) 2-stroke 1987-1995
• 150 hp, V6 (2596cc) 2-stroke 1984-1996
• 175 hp, V6 (2596cc) 2-stroke 1984-1996
• 200 hp, V6 (2596cc) 2-stroke 1984-1996
• 220 hp, V6 (2596cc) 2-stroke 1984-1987
• 225 hp, 76 deg. V6 (3130cc) 2-stroke 1994-1996, 225 hp, 90 deg. V6 (2596cc) 2-stroke 1987-1996
• 250 hp, V6 (3130cc) 2-stroke 1990-1996.

Book Excerpt: 1984-1996 Yamaha Outboard Motors: 2-250 HP, 1-4 Cylinder, V4 and V6 2- and 4-Stroke Models Including Jet Drives IGNITION AND ELECTRICAL SYSTEMS

TROUBLESHOOTING ELECTRICAL SYSTEMS When diagnosing a specific problem, organized troubleshooting is a must. The complexity of a modern marine vessel demands that you approach any problem in a logical, organized manner. There are certain troubleshooting techniques, however, which are standard:

• Establish when the problem occurs. Does the problem appear only under certain conditions? Were there any noises, odors or other unusual symptoms? Isolate the problem area. To do this, make some simple tests and observations, and then eliminate the systems that are working properly. Check for obvious problems, such as broken wires and loose or dirty connections. Always check the obvious before assuming something complicated is the cause.
• Test for problems systematically to determine the cause once the problem area is isolated. Are all the components functioning properly? Is there power going to electrical switches and motors? Performing careful, systematic checks will often turn up most causes on the first inspection, without wasting time checking components that have little or no relationship to the problem.
• Test all repairs after the work is done to make sure that the problem is fixed. Some causes can be traced to more than one component, so a careful verification of repair work is important in order to pick up additional malfunctions that may cause a problem to reappear or a different problem to arise. A blown fuse, for example, is a simple problem that may require more than another fuse to repair. If you don't look for a problem that caused a fuse to blow, a shorted wire (for example) may go undetected and cause the new fuse to blow right away (if the short is still present) or during subsequent operation (as soon as the short returns if it is intermittent).

TRIM and TILT SYSTEMS

HYDRO TILT LOCK SYSTEM DESCRIPTION AND OPERATION
(See Figure 1) The Hydro Tilt Lock system consists of a single shock absorber. The shock absorber contains a high pressure gas chamber located in the upper portion of the cylinder bore above the piston assembly. The piston contains a down relief valve and an absorber relief valve. Below the piston assembly, the lower cylinder bore contains an oil chamber. This lower chamber is connected to the upper chamber above the piston by a hydraulic line with a manual check valve. This check valve is located about half way down the hydraulic line. This manual check valve is activated by the tilt lever, when the lever is rotated from the lock (down) position to the tilt (up) position. The check valve cam rotates and pushes the manual check valve push rod against the check valve. This action opens the check valve and allows hydraulic fluid to flow from the lower chamber through the hydraulic line, past the open manual check valve and into the upper gas chamber.

RAISING OUTBOARD UNIT

When the outboard unit is tilted up, the volume below the piston decreases, and at the same time, the volume above the piston increases until the piston has reached the bottom of its stroke. In this position all fluid is contained above the piston. The tilt lever is then rotated to the lock (down) position to engage with the clamp bracket. When the tilt lever is in the lock position, the manual valve push rod rests on a flat spot of the manual valve cam and releases pressure on the check valve. Releasing pressure on the check valve closes off the hydraulic line and the flow of hydraulic fluid. The outboard unit is not in the trailering position.

Subject: 1984, 1985, 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996 Yamaha 2-250 HP, 1-4 Cylinder, V4 and V6 2- and 4-Stroke Models Including Jet Drives service, maintenance, repair. ISBN-10: 0893300640 | ISBN-13: 9780893300647 | Seloc 1701