Workboat

Maintenance

Engine Problems Solved

What are your problems with marine engines, power pumps, generators or other engine gear? This month PIM starts a question-answer service for planters. Send us your questions and our technical expert will answer them through the columns of Practical Planter. To get the ball rolling, our man answers

some representative problems.

Drop In Power

I have an air-cooled diesel engine in a general purpose work boat.

Lately I have noticed a drop in power and rpm, even though the fuel filters are kept clean and the engine oil is changed regularly. How can I remedy this?

A. There are several answers to this one. Worn piston rings and/or valve seats can cause loss of com pression. We suggest you grind in your valves before changing piston rings. Check your in jectors. A leaky injector, while apparently firing properly, can give poor combustion. Check also your exhaust line and silencer for back-pressure—a common fault often overlooked. If your pro peller is fouled it will lower your rpm.

Vibration In Engine

We have noticed a vibration in our popular and efficient diesel engine.

The vibration varies at different speeds. It is not noticeable in neutral and the engine is very satisfactory otherwise. What can we do about this?

A. Examine your propeller. A bent blade or pitch variation in the propeller—even a small one—will tend to unbalance your engine.

Check your tail-end bearing on the propeller shaft—a slack or worn bearing will create a knock with a vibration which can be transmitted back through to the engine. Check your propeller shaft in case it is bent.

Reverse Gear Worn

We have a good petrol engine in our small launch. It is not new but still very good and reliable. However, our reverse gear is very badly worn and we are told that the gear—a Joes—is out of production. Is this so?

A. I have checked with the original makers—production has ceased.

I suggest you fit a modern reverse gear, and I will give you the addresses of supplying companies.

What Type Of Jointing?

Would you please tell me what type of jointing I should use on my fuel pipe line? I find that red lead compound is not satisfactory. Also, can you recommend a control which will not rust up if left for a few days?

A. To your first question—with petrol, kerosene or distillate you should use a litharge-glycerine base jointing. There are several brands on the market. When using it on unions, flanges, etc., allow to dry for 12 hours if possible. In re gard to your second question, I can send you the names of con trol equipment available in Aus tralia. • Questions for this department should be addressed to: The

Editor, Practical Planter section,

Pacific Islands Monthly, GPO Box

3408, Sydney, NSW, 2001.