Diagnostics -Mechanical

Correct propeller and drive ratio?

–Compare with other similar models

–Check ratio versus the label if a problem since first use

–Check hub for slipping

Bottom paint added or fouling present

–marine growth or barnacles?

Excessive load?

–Is this a new problem?

–Anchor chain in bow locker?

–Dingy or personal watercraft added?

–Any new weight added?

Reduce prop size by 1 (inch or size) for every 1000 additional pounds.

One of the most common complaints we hear is poor top end performance. If the engine does not meet it’s rated RPM, it will not meet it’s rated horsepower. This leads to trying to troubleshoot a perfectly good engine. Left unresolved it can lead to high combustion temperatures due to engine overload that will cause valve or piston damage.

If the problem has existed since the very first day, check the weight of the boat at some local scales. Compare the prop size, drive ratio and performancewith similar sized boats. Be sure to allow for addition of bottom paint and other factors relating to load. Also be sure to check the exhaust for restrictions.

Diagnostics -Electrical

• Battery capacity a minimum of 650CCA “starting”battery.

• Optional accessories added to the engine wiring? (if alternator capacity is exceeded, then a storage battery is required to supply additional current needs)

• Battery cabling of the correct gauge?

• Are the ground stud/cables tight?

• Remove wing nuts and use nylocknuts for a more secure connection

• Check battery switch connections if appropriate

• Battery Isolators can cause voltage drop to ECM

Battery Isolator Installation Bulletin

Fuel injected engines and the computers that run them require consistent voltage supply. A battery that has too few cold cranking amps or using a deep cycle battery for starting can lead to low voltages during cranking. If the voltage is severelylow, you can have a crank, but no start condition. If it does start, it can change the “Baro derived from MAP”, which can lean the fuel mixture thinking it is now at high altitude (as talked about earlier in this book). An analog voltmeter such as the one on the dash can be very helpful here. A digital meter moves too fast and does not allow you a clear picture of the voltage drop during cranking (unless it has a record function).

Be aware also that the typical emergency stop switch interrupts the power lead from the key switch to the ECM. Test the voltage in and out of this switch ifso equipped.

Volvo Penta of the Americas

1300 Volvo Penta Drive

Chesapeake, Virginia 23320-9810

Battery isolators, correct installation

Models: EFI engines, see list

Distribution: MDate: Apr-2005Binder: C

Engines affected;

4.3GXi; -C,-CF,-D,-DF,-E,-EF5.7OSi; -B,-BF,-C,-CF,-D,-DF

4.3OSi; -C,-CF,-D,-DF,-E,-EF5.7OSXi; -B,-BF,-C,-CF,-D,-DF

5.0GXi; -C,-CF,-D,-DF,-E,-EF8.1Gi; -C,-CF,-D,-DF,-E,-EF,-F,-FF

5.0OSi; -C,-CF,-D,-DF,-E,-EF8.1GiI; -C,-D,-E,-F,

5.7Gi; -C,-CF,-D,-DF,-E,-EF8.1GXi; -B,-BF,-C,-CF,-D,-DF,-E,-EF

5.7GiI; -C,-D,-E,8.1GXiI; -B,-C,-D,-E

5.7GXi; -D,-DF,-E,-EF,-F,-FF8.1OSi-; -A,-AF,-B,-BF

5.7GXiI; -D,-E,-F

EFI engines have been found in the field with incorrectly installed battery isolators. This can lead to voltage drops in the electrical system and poor battery charging. If these symptoms are present, check the installation of the isolator. The installation should comply with the guidelines below.

Correct installation of battery isolators

Caution! Disconnect all power to the engine before proceeding

A. Disconnect alternator from engine harness;

At Bussman fuse/relay box, Remove gray connector with orange wire (C) from box.

Tape or tie strap the connector/wire to engine harness.

Install sealed connector 3817796 in box where gray connector/wire was removed.

B. Connect alternator to isolator; Note! The alternator output wire assembly, which carries alternator output to the isolator, is critical to correct operation of the charging system. The wire must meet all current ABYC specifications regarding materials, attaching terminals and routing and protecting the wire.

At rear of alternator, Remove ring terminal/orange wire/ boot (OR) from the B+ terminal. Remove ring terminal (T) and boot (B) from wire, save boot.

Seal cut end of wire with electrical tape or liquid tape. Tape or tie strap the wire (OR) to engine harness.

Alternator and wire (OR) are now disconnected from the engine harness.

Note! Wire size of the output wire is critical to correct operation of the isolator and charging system. Wire size is determined by the total length of wire. The size of the output wire used in the installation must meet these ABYC standards; 0 - 3m (0-10 ft)6 AWG 3m to 6m (11-20 ft)4 AWG over 6m (over 20 ft)2 AWG

Using the correct wire size ensures that voltage drop occurs through the isolator diodes, and not in the wire.

Place boot (B) over output wire. Install a 5/16” or 8mm ring terminal (N) on output wire.

Recommended terminal has mechanical crimping of the wire’s conductor and a heat shrink seal.

Install ring terminal/boot/wire on B+ stud on alternator.

Nut torque = 10-17Nm or 7-13 ft/lbs Route the wire to avoid sharp edges or other chafe points. Sheathing the wire is recommended.

Complete the wiring of the battery isolator per manufacturer's recommended procedures.