This Clymer repair manual covers 1972-1989 Mercury 3.5-40 HP, including electric motors:

• Mercury 3.5, Mercury 3.6
• Mercury 4 (40), Mercury 4.5 (45)
• Mercury 5
• Mercury 6
• Mercury 7.5 (75)
• Mercury 8
• Mercury 9.8 (110), Mercury 9.9
• Mercury 15
• Mercury 18
• Mercury 20 (200), Mercury 25
• Mercury 35
• Mercury 40 (402)

Book Excerpt: 1972-1989 Mercury Outboard 3.5-40 HP Repair and Service Manual TROUBLESHOOTING

STATOR TEST

1. Disconnect the red and blue stator leads at the terminal block on the left corner of the front support bracket.
2. Connect an ohmmeter to the blue stator lead and a good engine ground. With the meter set on the R X 1,000 scale, it should read 5-6 ohms.
3. Connect the ohmmeter to the red stator lead and a good engine ground. With the meter set on the R X 1 scale, it should read 50-60 ohms.
4. If the stator assembly performs as indicated in each step, reconnect the leads to the terminal box. If it does not, replace the stator assembly. See Chapter Seven.

LOWER UNIT

WATER PUMP: REMOVAL AND DISASSEMBLY Mercury Marine recommends that all seals and gaskets be replaced whenever the water pump is removed. It is also a good idea to install a new impeller at this time. Figure 16 (pressure type) and Figure 17 (volume type) are exploded views of the typical water pumps used with Merc outboards. MERC 3.5, 3.6 AND 2-CYL. 4 HP

1. Secure the gear housing in a suitable holding device or a vise with protective jaws. If protective jaws are not available for the vise, position the unit upright with the skeg between wooden blocks.
2. Remove 2 locknuts and flat washers holding pump cover to gear housing.
3. Slide centrifugal slinger, pump cover and face plate off drive shaft (Figure 18).
4. Pry impeller from water pump insert with 2 screwdrivers. Remove impeller from drive shaft.
5. Retrieve impeller drive key from pump insert with needle nose pliers.
6. Remove locknut and flat washer holding pump base to gear housing.
7. Carefully pry pump base from gear housing with a screwdriver.
8. Remove and discard pump base gasket. Remove metal insert from pump base. Pry oil seal from pump base.
9. Pull water tube guide from pump cover with pliers and a rotating motion.
10. Insert a small tapered punch in cover as shown in Figure 19. Push in and up on tube seal tab with punch. Remove seal and plastic washer under seal from cover. Discard seal; save washer.
11. Pry oil seal from pump cover.

Subject: 1972, 1973, 1975, 1976, 1977, 1978, 1979, 1980, 1981, 1982, 1983, 1984, 1985, 1986, 1987, 1988, 1989 Mercury Outboard 3.5-40 HP and electric motors service, maintenance, repair. ISBN-10: 0892873957 | ISBN-13: 9780892873951