Yachting and Motor Boating

Progress, Volume VII, Issue 4, 1 February 1912, Page 979

Yachting and Motor Boating

BY E. W. HURST HOUSE.

Hints to Marine Motorists.

The successful running of a marine motor engine—as the expert very well knowsdepends not only upon the mere

fact of knowing how to start the engine, but upon a thorough knowledge of the principle of the explosion and generation of power, a close intimacy with all the working parts, including the electric outfit, and by being conversant with the symptoms leading to irreguWilli lllp LUIIIO £ vu 11 IvJgU" larities. One soon learns to know how to start an engine, and is inclined to the belief that so long as it runs nicely, no further knowledge about it is requisite. There are, however, so many points to be learned, and so much pleasure in learning them, that I am inclined to the

view that many of us would find motoring a very dull pastime, had we not at some time or other an opportunity of displaying our knowledge, and getting at the root of the trouble. Before you can be considered expert enough to take charge of a motor, for

instance, during a race, you must have studied every point about your engine, found out all its peculiarities, in smooth and rough water, running with or against the tide and wind, be conversant with the causes of all failures to run at its best, and to be so much a part of your engine that if anything goes wrong you can in an instant place your finger on the defect. This, of course, aplies also in ordinary cruising, but how much more when racing. The object of this article, then, is to point out some of the causes of failure, and generaly to offer suggestions for the

successful running of a marine motor engine. It will be taken for granted that you have some knowledge of the various parts and the functions each performs; these will have been explained to you, either from catalogues or by the firm from

whom you purchased the engine. This suffices for a beginning—other knowledge is. however, required later, either from your own or another’s experience. Possibly the two chief causes of failure are found in a faulty ignition or incorrect explosive mixture. Taking the first cause. There are three common methods of generating the current 1. By means of storage batteries and an induction coil or coils. 2. By means of a low tension magneto machine. 3. By means of a high-tension magneto machine. The object of each system

being to produce a spark of sufficient intensity to cause the compressed charge of gas to explode. Whatever the system be, you must get a thorough hang of it, because you will find nearly all your double arises from a faulty electric system.

The failure to produce a good spark may be caused by—1. A dirty sparking plug. This should be examined first and tested. 2. The trembler of the coil having become loose and out of adjustment, or the contact points become corroded. 3. Comutator dirty or out of adjustment. 4. Wires loose or broken. 5. Driving mechanism to magneto at fault. 6. Magneto itself out of order. When a defect occurs examination should be made in some systematic order —the writer prefers that as given above. If you are using an accumulator, the following will be worth remembering:— Care must be taken that the + terminal of accumulator is always connected to the + wire of supply, which may be readily found by applying a piece of wetted pole-finding paper to the two supply terminals. The negative wire will then discolour the paper in its neighbourhood. Note. —If pole-paper is not available connect a length of wire to each terminal of the supply, and clean the other ends and hold them apart in a vessel containing slightly acid water. The wire connected to the negative pole will give off bubbles of gas. The battery may be known to be fully charged when the bubbles are given off very freely, the fluid becomes very milky, and the voltmeter shows 4.4 volts when connected, which gradually drops to 4.2. N.B.—Care must be taken that the + wire of supply is always connected to the + terminal of accumulator, the latter being painted red. Accumulator Troubles.— the cell takes longer to charge than usual, does not show more than 2.2 volts when charged, and lasts a short time only, buckling or internal short circuiting is probably the cause. Charge fully, shake gently and pour out acid quickly. If acid

is very muddy and fine powder present, powdering has taken place. If acid is clear but there is a granular deposit, buckling is the cause. 1. Acid should cover plates; if not, add water, not acid, unless cell is leaking or some has been spilt. 2. To add acid ,

use mixture before mentioned, wait till it is cool before filling. 3. Do not leave cells discharged. 4. Never “spark” the terminals of the cells to see if they are charged; this does great harm and produces buckling. As so much depends upon the condition of the cells, special care should be given to them. Defects which may appear are:— Internal Short-circuiting.—Due to charging at too high a rate, discharging

too rapidly, careless or rough handling. Caused by pieces of the lead dropping out and making short circuit between the plates. Buckling.—Caused by charging or discharging too rapidly. Plates warp and short circuit sets up'.

Sulphating.—Shown by white spots or patches on the edge of plates, caused by allowing cells to become and remain empty. This insulates the plates and reduces their output greatly. Sulphating may be remedied by putting .a pinch of washing soda into each cell and charging with a very weak current for a long time. Powdering of Paste. Due to weakness of acid, paste softens and crumbles away, falling to the bottom, and short circuiting. Leaky Casing.— careful always to guard against leaks. A leaky battery is a never-ending trouble, and may mislead you. Terminals. —Much depends upon securing good connections throughout the electrical circuits and particularly on the lowtension circuit, that is, from the battery to the comutator and coil. The ends of the wires should be made clean and bright; the wires should be twisted round the terminal screws in such a manner that they are not likely to shake or pull loose, and the set screws or nuts should be set up to hold the wires securely. It is a good plan to cover the terminals on the accumulators with a good coat of vaseline after the connections are made, as this serves to protect them from corrosion by the fumes of the acid in the cells or from any liquid that may be slopped over. All wires and connections should be properly covered and protected from water, spray or rain, as otherwise there may be a risk of short circuit. For the same reason, wires, however well insulated, should not be led through the bilge, where they are likely to be subjected to continual splashing with oil and water. Oil will rot the rubber insulations and water may then penetrate and set up short circuiting. The failure of the engine to run satisfactorily is also very often due to—-

1. Insufficient petrol supply (nozzle may be choked, or tank empty. 2. Too much petrol (carburettor flooded)—this will be seen by the blackish fumes from exhaust. 3. Needle • valve in float box jammed ' (To be continued.)