This repair manual covers 1964-1986 OMC Stern Drive units with the following engines:

• Ford 90
• Ford 302
• Ford 351W
• General Motors 2.5L
• General Motors 3.0L
• General Motors 225
• General Motors 229
• General Motors 250
• General Motors 262

Book Excerpt: OMC Stern Drive Ford, GM 1964-1986 Repair Manual LAY-UP, COOLING SYSTEM SERVICE AND FITTING OUT

OUT-OF-WATER PREPARATION

1. Adjust trailer or cradle so that engine is in a level position. Lower stern drive unit to its "down" position.
2. Loosen drive belt tension and inspect condition of al belts. Replace as required. Tighten accessory unit adjusting bolts without putting tension on drive belts.
3. Drain cooling system as described in this chapter.
4. Check all hoses for deterioration, cracks or other defects and replace as required.
5. Remove the spark plugs and pour one ounce of SAE 30 SF engine oil into each cylinder.
6. Disconnect coil high tension lead at coil (Figure 7). Ground lead and crank engine over 15-20 seconds with the starter to coat cylinder walls with oil.
7. Wipe up any excess oil from plug holes. Wipe a thin film of SAE 30 engine oil on spark plug threads. Reinstall spark plugs and connect coil lead.
8. Remove the rocker arm cover(s) and check for signs of condensation in the rocker arm area. Carefully wipe away any oil-water mixture found. Coat valve mechanism and inside of rocker arm covers(s) generously with SAE 30 engine oil. Reinstall rocker arm cover(s) using new gasket(s).

ELECTRICAL SYSTEMS

IGNITION SWITCH Disconnect the negative battery cable when testing the ignition switch in the boat. Refer to Figure 45 for this procedure. Terminals M and C on the switch are not used in stern drive applications.

1. Disconnect all leads at the ignition switch.
2. Connect an ohmmeter or self-powered test lamp between the B and A terminals.
3. Turn the switch ON and then to START. There should be continnuity in both switch positions.
4. Move ohmmeter lead form A to S terminal. Turn key to START position. There should be continuity.
5. If the switch fails to indicate continuity as described in any position, replace it.

Subject: 1964, 1965, 1966, 1967, 1968, 1969, 1970, 1971, 1972, 1973, 1974, 1975, 1976, 1977, 1978, 1979, 1980, 1981, 1982, 1983, 1984, 1985, 1986 OMC Stern Drive Ford and GM service, maintenance, repair. ISBN-10: 0892873981 | ISBN-13: 9780892873982