REPAIR JOBS

Rotorua Morning Post, Volume 2, Issue 237, 27 May 1932, Page 2

REPAIR JOBS

WORK WHICK AMATEURS SHOULD LEAVE ALONE. EXPERIENCE NEEDED. One point which is seldom stressed by writers on motoring subjects is that there are eertain cepair jobs which are far better left alone by the enthusiastic amateur. Others, again, should be attempted only after considerable mechanical experience has been gained. Decarbonisation of an engine with side-by-side valves, or having overhead valves operated by rocVers and push rods, is quite a simple matter for anyone capable of following simple instructions. If the engine, however, has an overhead camshaft, miy an experienced amateur can be rure of escaping a great deal of tr^uble in retiming the valves of all but a few such designs. These remarks, of conrse, must not be taken as a condemnation of engines of this class. Uspally they combine quietness with efficiency and dependability to quite an unusual degree, and need a minimum. of attention to valves and tappets. Carburettors, vacuum tanks and fuel pumps, except for cleaning, are an expert's job. It needs a good deal of experience properly to adjust & earburettor, and the fitt'ng of jets which are too sinall in an actempt to improve fuel consumption beyond a eertain point is likely to cause lurnt valves and other troubles. Similarlv, power will be lost if a eertain jet is exceeded, with waste of fuel and inpid ' carbonisation. Considerable varia- ; tions from normal p'erf ormance stand■ards require alterations of other factors, ' such as choke area. Particularly should interference with the modern types of fuel pumps ,be avoided. They ar'e extremely reliable, but in many cases require special tools for reassembling, and therefore should be dismantled b^ an authorised serviee man. In making adjustments such as tappet, plug and hreaker gap settings, accuracy is of great importance, and a set of feeler gauges should be obtained. The repair of electrical units should be regarded as a specialist job. This applies to a eertain extent also to the setting of breaker gaps in cases where twin magnetos or distributors, or twin breaker arms are used. The whole advantage of such arrangements, which in some cases is very marked, will be lost as a result of apparently the most trivial inaccuracy. A great deal depends on possession of the right tools. Adjustments involving the meshing of gears accurately, such as silencing a noisy crown wh'eel and pinion, should be undertalcen only by an experienced mechanic. The same applies to work on the reciprocating parts of the engine, such as bearing adjustments.