Indmar 5.7L Vortec Operator's Manual page 80

7. Insufficient air supply to engine
8. Engine needs tune-up
9. Damaged or incorrect propeller
10. Engine needs to be adjusted for high altitude
operations
11. Engine needs to be adjusted for temperature
extremes
Engine Cranks / Won't Start
1. Weak or shorted coil; no spark at plugs
2. Loose engine grounds
3. Lack of fuel at carburetor (carbureted engines only)
4. Weak or discharged battery
5. Boat Engine Safety switch not attached
6. Vapor lock
Idle — Misses or Runs Rough
1. Spark plugs fouled or cracked
2. Spark plug or distributor wires loose or shorted
3. Plugged positive crankcase ventilation system
4. Engine in need of tune-up
5. Engine needs to be adjusted for high altitude
operations
6. Engine needs to be adjusted for temperature
extremes
7. Carburetor out of adjustment (carbureted engines
only)
8-2
Hard Start Hot
1. Flooding condition
2. Loose electrical ground at engine
3. Closed choke (carbureted engines only)
4. Plugged flame arrestor
5. Fouled spark plugs
6. Loose coil or ignition wires
7. Battery cables loose or corroded
8. Weak or discharged battery
9. Vapor lock
Engine Won't Crank
1. Weak or discharged battery; loose or corroded
battery cables
2. Defective neutral safety switch or adjustment needed
3. Defective starter motor
4. Ignition switch problems
5. Hydrostatic lockup — remove spark plugs to look for
water or gasoline in cylinders
6. Seized engine — turn crank pulley with socket and
ratchet
Indmar Marine Engines