Beta Marine Beta 10 Operator's Maintenance Manual page 33

Problem: Water in lubricating oil - keel cooled
Possible Cause
Oil goes "milky" due to water entering exhaust
manifold and then into the sump:
Problem: Engine overheats
Possible Cause
Check coolant level:
Pressure cap loose:
Switch sender faulty:
Insufficient restrictions in pipe to calorifier:
High exhaust back pressure:
Keel cooler insufficient size:
Problem: Engine overheats - Heat exchanger only
The most common cause of overheating is insufficient seawater flow due to a blocked intake (weed or a plastic bag!). If
this happens then clear the blockage. If the problem is not cured then check the system for sea water flow which should
be 15 litres / minute minimum at 1,500 rpm as follows:
(a) With the boat tied up and out of gear run the engine up to 1500 rpm. Hold a plastic bucket over the exhaust outlet for
10 seconds and measure the amount of water collected*. Multiply this value by 6 to give the flow in litres/min. Repeat
twice and take an average. If the flow rate is noticeably less than the 15 litre per minute minimum at 1,500 rpm, then:
(b) Check impeller in sea water pump - if worn replace.
(c) If impeller has a vane missing then this will be lodged either in the pipe to the heat exchanger or in the end of the
exchanger. This must be removed.
(d) Check flow again as in (a).
*Note: This operation must only be done in safe conditions, in port and with two assistants. Working from a rubber dinghy
is best. The person holding the bucket should take precautions against breathing in the exhaust gasses.
Problem: Engine overheats - Keel cooling only
Sometimes overheating is caused by:
(a) Not fully venting the engine cooling system of air. It is necessary to remove all air from the cooling system - including
the "skin" tanks and (if fitted) the Calorifier and associated piping.
(b) Incorrectly sized "skin" tanks that have been sized for 'usual' canal use (rather than maximum engine output that can
sometimes be required) on fast flowing rivers. An additional "skin" tank may need to be fitted; please refer to our
website: Inland waterways - Guidelines: keel cooling tank sizes.
Solution
Check installation - has dry exhaust system been fitted
correctly, and ensuring rain water cannot enter the
exhaust port and run back? (See Dry Exhaust System).
Change engine oil and run engine for 10 minutes each
time to eliminate any water. Get injection pump checked
by Service Agent.
Solution
Top up.
Tighten correctly or replace.
Replace.
Clamp off pipe to confirm.
Beta 10 to Beta 25 maximum 70 mmHg;
Beta 30 to Beta 60 maximum 80 mmHg,
and Beta 75 to Beta 105 maximum 90 mmHg.
Contact boat builder
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