This repair manual covers 1964-1985 Mercruiser Model 0, Model I, Model II, Model II-TR, Model II-TRS, Model III, and Model 215, including 1986-1987 TR and TRS.
GM Inline: 4-cylinder 153 and 181 cid | 6-cylinder 194, 230, 250, and 292 cid
Book Excerpt: Mercruiser Stern Drive Repair Manual 1964-1985 (plus 1986-1987 TR, TRS)
GM V6: 229 and 262 cid
GM V8: 283, 305, 327, 350, 409, 427, 454, and 482 cid
Ford V8: 302 and 351W cid
MerCruiser: 60, 80, 90, 470, 485, 488, 170MR, and 190MR
Fuel system problems must be isolated to the fuel pump, fuel lines, fuel filter or carburetor. The following procedures assume that the ignition system is working properly and is correctly adjusted.
CYLINDER HEAD: REMOVAL
- Engine will not start ? First make sure that fuel is being delivered to the carburetor. Remove the flame arrestor, look into the carburetor throat and operate the throttle linkage several times.
There should be a stream of fuel from the accelerator pump discharge tube each time the throttle linkage is moved (Figure 15). If not, check fuel pump pressure as described in Chapter Eleven.
Also check the float valve and float adjustment. If the engine will not start, check the automatic choke parts for sticking or damage. If necessary, rebuild or replace the carburetor.
- Engine runs at fast idle-Check the choke settings. Check the idle speed and mixture adjustments.
- Rough idle or engine miss with frequent stalling. - Check idle mixture and idle speed adjustments.
- Engine ?diesels? (continues to run) when ignition switch is off. Check idle mixture (probably too rich), ignition timing and idle speed (probably too fast). Check for engine overheating.
- Engine stumbling when accelerating from the idle- Check the idle speed and mixture adjustments. Check the carburetor accelerator pump.
- Engine misses at high speed or lacks power- This indicates possible fuel starvation. Check fuel pump pressure as described in Chapter Eleven. Check float needle valve(s). Check for a clogged fuel filter or dirty flame arrestor.
- Black exhaust smoke-This indicates a badly overrich mixture. Check idle mixture and idle speed adjustments. Check choke settings. Check for excessive fuel pump pressure, leaky float(s) or worn needle valves.
Perform steps 1-8 if engine is in boat. If engine has been removed from boat, begin with Step 9.
- Remove the intake and exhaust manifolds as described in this chapter.
- Open the engine block drain valve(s) and allow the water to drain.
- Disconnect the fuel line support clamps. Remove the fuel line.
- Disconnect the cooling hoses at the water distribution housing.
- Disconnect the temperature sending lead and remove the water distribution housing.
- Disconnect and remove ignition coil.
- Remove circuit breaker bracket and engine lifting eye.
- Disconnect all spark plug cables. Remove the spark plugs.
- Remove the rocker arm cover as described in this chapter.
Subject: 1964, 1965, 1966, 1967, 1968, 1969, 1970, 1971, 1972, 1973, 1974, 1975, 1976, 1977, 1978, 1979, 1980, 1981, 1982, 1983, 1984, 1985 Mercruiser Stern Drive plus 1986, 1987 TR, TRS service, maintenance, repair. ISBN-10: 0892876131 | ISBN-13: 9780892876136