Overheat Warning all VRO Models
The overheat warning circuit consists of two sending units mounted in the cylinder heads and connected to the warning horn through the key switch.
The warning horn is activated when the powerhead exceeds 99 degrees Celsius (211 degrees Fahrenheit). The horn will sound continuously.
If horn sounds, back off throttle until horn stops.
If horn continues to sound, stop the engine immediately and check for a restricted water intake.
Start the engine and run it at a fast idle in neutral, or shift to forward and proceed slowly, observing the water pump indicator which should discharge a steady stream of water.
You may have to allow the engine to run for about 2 minutes to allow the powerhead to cool. The warning horn is deactivated when the powerhead cools to 79 degrees Celsius (175 degrees Fahrenheit).
If the indicator does not resume discharging a steady stream or if the horn continues to sound after 2 minutes, stop the engine immediately or serious powerhead damage may occur.
Cylinder heads should be retorqued after the engine has been overheated and the warning horn has sounded. This will reduce the chance of permanent powerhead damage due to blown cylinder head gaskets.
Servicing VRO Equipped Models
Since the warning horn is used for two systems in the V-4 models and three systems in the V-6 and 2.6 models, the horn should be tested to make sure it is sounding each time the engine is brought in for service.
Slide the insulating sleeve aside to expose the knife disconnect between the temperature switch and the horn lead.
Turn key switch to “ON” position.
Touch terminals to a good ground on engine block.
The horn should sound; if not, check wiring and horn for problem.
A spark arrestor is installed in the pulse hose to the VRO pump. A clamp is positioned on the hose to prevent the spark arrestor from migrating up the hose to the pump. If it is necessary to remove the pulse hose at the engine, make sure the spark arrestor stays in the hose.
Failure to position the spark arrestor in the pulse hose may cause permanent damage to the VRO pump.
Oil Inlet Filter - A filter is provided in the clear oil inlet hose to the VRO pump. This should prevent any dirt from entering the pump. If the filter requires cleaning, the hose assembly should be carefully removed and reverse flushed using clean solvent. Do not attempt to remove the filter as the hose and filter are serviced as an assembly.