cA fuel transducer may be clogged. If so, remove the transducer from the fuel line and gently blow through it in the opposite direction to the fuel flow.
A fuel filter between the fuel transducer and the fuel tank must be installed as per the fuel installation guide. Failure to do so will void the warranty.
dInspect the fuel cable from end to end for damage such as cuts, breaks, trapped or squashed sections.
eCheck that the fuel filter is clean.
3-3 A twin engine installation shows only one flow rate:
aCheck that the number of engines is set to 2 (see section
3-4 Erratic Fuel Flow readings:
aThe fuel flow transducer may have been mounted too close to the fuel pump or may be subject to excessive vibration. Refer to the installation instructions supplied with the fuel transducer.
bCheck for leaks in the fuel line or in the fuel pickup in the tank.
cThe Flow filter value is not suitable for the engine. Check that the value is not set to zero, then try increasing the value until a steady flow rate is shown (see section
3-5 There is no reading for fuel economy:
aThe boat must be travelling through the water to generate an Economy reading.
bCheck that the paddlewheel on the transducer is spinning freely and that the two magnets in the paddlewheel are still in place.
B-4 Sonar fishfinding problems
4-1 The 657 operates erratically:
aCheck that the transducer does not have debris (e.g. weed, plastic bag) caught around it.
bThe transducer may have been damaged during launching, running aground or while underway with debris etc. If the transducer has been impacted, it may have been kicked up on the bracket. If it is not physically damaged, reset the transducer back to its original position. (See the Transom Transducer Installation Guide.)
cWhen the transducer is less that 2 ft (0.6 m) from the bottom, the depth readings may become inconsistent and erratic.
dManual Gain may be set too low, which may cause weak bottom echo or no fish signals. If in Manual Gain, try increasing the Gain.
eEnsure the back of the bottom surface of the transducer is slightly lower than the front and the front is as deep in the water as possible in order to minimize the generation of bubbles through cavitation. (See the Transom Transducers Installation Guide)
fCheck the transducer and power cable connectors at the back of the display unit
are securely plugged in and the collars are locked in place. The collars must be secure for watertight connection.
gInspect the power cable from end to end for damage such as cuts, breaks, squashed or trapped sections.
hEnsure there is not another fishfinder or depth sounder turned on, which may interfere with this 657.
iElectrical noise from the boat’s engine or an accessory may be interfering with the transducer(s) and/or the 657. This may cause the 657 to automatically decrease the Gain unless using Manual Gain.
The 657 thus eliminates weaker signals such as fish or even the bottom from the display. This may be checked by switching off other instruments, accessories (e.g. bilge pump) and the motor until the offending device is located. To stop problems from electrical noise, try:
-
-routing the display unit’s power cable directly to the battery with an
88 | Northstar Explorer 657 Installation and Operation Manual |