SPRING OVERHAUL.

Auckland Star, Volume LX, Issue 229, 27 September 1929, Page 14

SPRING OVERHAUL.

TUNING UP THE ENGINE.

HINTS FOR AMATEUR ENGINEERS.

AKARANA'S THIRTY-FOURTH ANNUAL MEETING.

Every spring the sailing fleet receives a general overhaul in readiness for tlie season, and some useful hints were lecently given in tliis column on the various work necessary to refitting. It must not he overlooked, even by the most ardent lover of sailing, that his brother sportsman, who owns a motor boat, is deserving of such help as can be given him on the work of reconditioning the engine, and the following notes should be found useful to motor boat men.

If not already done, the engine should receive a thorough overhaul, the extent of which will depend on the quality of the motor, its age and the amount of use (or abuse) it has received. An engine of one of the dozen or so good makes, British and American, should not require much overhauling after its first year. The writer Is a great believer in letting well alone on a new job. Some years ago he was persuaded that an engine, which ran well during the whole of its first year, should be taken ri°ht down. This was done, although beyond a little carbon, nothing was wrong with it, but when put together again" it never ran as well as it did the first year.

On the first year's engine the only work should be to clean out the caibon, grind in valves and adjust breaker points and ignition jrenerallv, clean the spark plugs °and drain the oil from the crankcase. This is all that should be necessary to put an engine one year old in good condition. On an engine which has run for two seasons the above work may require to be supplemented by taking up the main and crank-shaft bearings. After its third season, the engine will want more work done to it. Crank-shaft bearings will require adjustment or renewal, and new piston rings should be fitted, while new spark plugs and wiring may be necessary. t

An engine four years old will need, in addition to this work, attention to the valves and valve stem guides. Warped valves and bent valve stems may appear and will cause loss of power. They should be renewed. After this age, the work gradually gets more extensive each •year, and will include new pistons and regrinding of the cylinders. Any engine, which lias seen five years' service in a boat without being taken down, is justly entitled to a complete overhaul at the hands of a professional engineering firm. If the engine is not a big, heavy job, it will be better to lift It out of the boat. After a thorough overhaul, including tlie replacement of all worn parts, it should be good for another four or five years, given reasonable care and attention. This work should be taken in hand at once to avoid any delay in getting the boat into commission by Labour Day. When making repair jobs yourself, remember, if it is necessary to dissemble any part, always put a tag or label on the part. Where gears mesh, mark them with a punch to-facilitate putting them together. This is especially necessary with timing gears, as a tooth too many will throw the whole job out. Clean the parts with kerosene, inspect for cracks or flaws and note their general condition.

The following will give an idea of the points needing attention, and the sequence of operations will be found to work well, although it is not absolutely necessary to follow any" set rule in the matter: — Crankcase. — Drain and refill with new oil and keep this up to the right level when in use. Grinding Valves and Removing Carbon. —This operation can be done by anyone who is in the habit of working on their engine. It is necessary to remove the cylinder head, scrape carbon from the piston heads and valves and regrind the valves. If the heads are warped or stems bent, they must be replaced as even if straightened out they will go again. The springs must be tested to find if they have lost tension. Valves are by coating their face with valve grinding compound, and rotating the valve about a quarter turn each way. A sprintr under the valve will lift it off its seat° each time the pressure of the "rinding tool is released. The pressure should not be heavy. Clean off tlie face and repeat the process until a uniformly bright surface is obtained. Do not get the° valves mixed. Adjust the tappet

clearance as recommended by tlie makers. From .004 to .OOGin, when the engine is warm, will be right. When replacing the cylinder head be sure the gasket is good. If in doubt, fit a new one. Ignitions.—Remove and clean all spark plugs. The gap should be .020 to .02oin. The breaker points should be cleaned, as dirt is a frequent cause of misfiring. Check over wiring and connections, and repair or replace damaged wires. Bearings.—lf an engine knocks or pounds when speeded up, the main and connecting rod bearings need taking up. These are usually fitted with laminated' (shims between the caps. Wh/en adjusting, the cap should be removed, and a shim taken from each side until the' bearing fits close to the crankcase. Pistons and Rings.—Pistons which have a rocking motion in the cylinder will cause piston slap. Excessive wear also allows dilution of the crank case oil. The remedy is to fit oversize' pistons and new rings, which often cures all such troubles. Piston pins and bearings can be tested by clamping the connecting rod in a vice and attempting to move the piston on its pin bearings. Fitting new piston pins and bushings should be done professionally. Cylinders.—lf these show a ridge at the "top of the bore, they want regrinding. Carburettor. —Clean the inside for foreign matter. Dry the float and give two thin coats of shellac. Renew any defective packing or gaskets. Adjustments should be made to carburettor when the engine is idle and when under load. Reverse Gear. —This is a portion which cannot be neglected. Generally, a good cleaning and adjustment of bearings is all that is required. An engine which has had new parts fitted should be handled as a new engine for the first 40 hours' running. The addition of a pint of lubricating oil to five gallons of fuel for the first ten hours' run will be an advantage. Whether the engine has been removed or not, it pays to realign with the propeller shaft. To test this, when the boat is afloat and going, pull out the clutch and if the propeller shaft continues to rotate from the drag of the water then the engine is not far out of alignment. Oil and water pumps should be inspected. New gears, packing, screens., plungers or check valves are not hard to replace. Water jackets should be flushed out with strong soda and water. New high tension wires are a good in-' vestment.

AEARANA CLUB.

34TH ANNUAL MEETING.

Tho Akarana Yacht Club held its thirty-fourth annual meeting in the clubhouse, Mechanics' Bay, last evening, Commodore T. McKay presiding over a good attendance of members. The annual report stated that the past season had been the most successful in the history of the club. Racing occupied five days, all classes being catered for, the entries being good all round. The most popular events were the cruising races to Awaroa and the Wade. The sum of £399 was paid off the clubhouse account in addition to the season's expenses. A special dance in aid of the Mayor's earthquake fund realised £7 for this worthy object. The club was represented at all social functions of sister clubs and a very cordial feeling exists between all clubs. The club's best thanks were due to the ladies' committee for their efforts on behalf of the clubhouse funds. Also to Mr. G. Miller for presenting a 7-footer to the club for use of the junior members. The balance-sheet showed receipts to include £74 from subscriptions, £37 entry fees, £47 donations, £90 locker rents, £239 socials and £26 art union. The expenditure included £203 for clubhouse account, £234 for general account and £34 for skidway. The liabilities were £442 on debentures, sundry accounts £172, bank overdraft £96, leaving a balance of assets over liabilities of £1636. The election of officers resulted as follows: Patron, Mr. H. R. Mackenzie; vice-patrons, Hon J. B. Donald and Mr. C. G. Macindoe; president, Mr." W. R. Ingram; vice-presidents, as last year; commodore, Mr. T. McKay; vice-com-modore, Mr. H. Howell; rear-commodore, Mr. H. Smith; hon. treasurer, Mr. H. Howell; assistant, Mr. F. W. Jeffers; hon. secretary, Mr. G. E. Laycock, assistant, Mr. W. Ure; clubhouse captain, Mr. Geo. Grimmer; hon. auditor, Mr. T. H. Hanson,* hon. solicitor, Mr. John Alexander, C.M.G.; hon. architect, Mr. M. K. DrafSn; chaplain, Rev. Jasper Calder; hon. measurers, Messrs. G. Miller and G. Grimmer; timekeeper, Mr. T. McKnigkt; judge, Mr. G. Grimmer; starter, Mr. G. Miller; recorder, Mr. G. E. Laycock; delegates to Yacht and Motor Boat Association, Messrs. E. B. Webster G. Miller; committee, Messrs. L. Heard, E. B. Webster, G. Grimmer, G. Miller, K. Peachey, L. Vickermann, E. Edgcumbe, T. Boswell, J. Skelton, C. Cook, C. Chapman and T. Carter.