Workboat

Maintenance

How To Go About

That Overhaul

The time comes when your workboat needs a thorough overhaul. Here’s a step-by-step account of how to go about it, prepared for PIM by a leading marine engine specialist.

1. Slip the craft and thoroughly clean the hull. Then, with a sharp pointed knife, lightly probe the keel, the lower plank ing, the stem and the shaft log.

If the knife finds easy entry in any of these areas look for borers or dry-rot. Caulking should be checked and, if necessary, renewed. 2. Look inside the hull and the stern and under the decking for dry-rot. The steering gear, from steering wheel to rudder, should be overhauled if possible.

Examine fastenings, wires, and the rudder shaft quadrant fitting. 3. Remove all floor boards and clean out the bilges, checking the bilge pump and pipes at the same time.

Check, renew

4. Thoroughly inspect the propeller and shaft. Examine the propeller nut (and lock-nut if fitted) for slackness, and check shaft and propeller for corrosion. If zinc plates or anodes are fitted, renew them—they are cheaper than propellers and shafts. Check rudder pintle bearing if fitted— since a loose bearing will cause vibration. The same applies if the tailshaft aft end bearing is worn. A loose, worn bearing will cause excessive wear to the shaft. Therefore, examine the stern tube aft end bolts and bearing.

5. If the engine exhaust outlet is aft, inspect the piping, and clean out the silencer. 6. With the engine, check the in jectors first and give the engine a top overhaul. This may not be necessary if the workboat hasn’t been used much, but a change of oil and good crank case flush out are always worth while. Renew the oil and fuel filter elements to get the full benefit of new oil. 7. If the engine has been running in a rough or uneven manner it may pay to re-calibrate the fuel injection pump. 8. Clean and flush out the reverse gear—residue from clutch plate wear can affect the ball bearings.

Adjust the ahead clutch and also the reverse band. Clean the re duction gear and renew oil. 9. Overhaul the water circulation system—unless it is air-cooled.

Examine the pump for wear and clean or- flush out all water jackets, including the fresh water heat exchanger. This is par ticularly important if the boat is operating in sandy or muddy water, since build up of silt will cause excessive pitting. 10. Finally, check the instruments and tachometer for accuracy. e Readers who wish to know more about workboat main tenance should address their

questions to: The Editor,

Practical Planter section, Pacific Islands Monthly, GPO Box 3408,

Sydney, NSW, 2001.