• ABOUT IGNITION TROUBLES.
Page 31
If you've noticed an error in this article please click here to report it so we can fix it.
Interesting Contributions from Our Driver and Mechanic Readers.
IGNITION _TROUBLES are engine troubles, and in stating, last week, that engine troubles were few and far between we incidentally, therefore, paid a compliment to the modern magneto, which, notwithstanding the inroads made by combined electric lighting and ignition outfits in the touring car world, still remains the supreme and most popular means of effecting the ignition DTI commercial-motor chassis. Out of three letters which we have selected for reference only two actually deal with troubles, and these are very exceptional indeed.
Both of these letters indicate to us that their writers possess, to an unusual degree, a capacity to surmount difficulties, and to effect running repairs. But the palm, which, in this case is the 15s. prize, must go to "-V.M.," of Rotherham.
It appears that following some ignition trouble, he examined the magneto and found that the condenser was beyond repair. Subsequent inquiries went to show that considerable time would elapse before a new one could be procured. It was not convenient, either, to borrow a magneto temporarily to replace
the damaged one. V.31.', therefore removed the condenser from the magneto, soldered the end of the primary winding to the plate into which enters the screw for securing the distributor plate, and then reassembled the magneto. He next removed the condenser from an old Ford coil, wrapped it up in a piece of rubber water hose, soldered a length of insulated wire to both condenser connections, sealed the condenser in the hose by running into it melted bitumen procured from the dismantled coil, and then clipped the substitute condenser to the magneto holding-down straps, connecting the wiring in the manner indicated in the sketch.
" V.31.'s " letter dealt with an unusual magneto breakdown, but it was not more strange and exceptional than
the one which occurred to " W.31.C.," of Stonehurst. He tells us that when on the road recently the engine suddenly petered out. He directed his attention to the carburetter, which, however, he discovered to be quite in order.
The next possible source of trouble was the magneto, and this was subjected to a preliminary examination in, situ. The platinum points appeared to be perfectly in order; the surfaces were good, and the make and break were effected in a satisfactory manner. The distributor was removed and the brush and segments examined. They also were as they should be. The collecting ring brush was then removed, cleaned and replaced. So far nothing had been discovered which was likely to have caused trouble.
The 'next thing to be thought of was the switch; this was tested by the usual method of removing the connection on the magneto dust cap. With this off, the engine was turned, but without any useful result, there being no sign of any current at the plug terminals. It was, however, still evident that the trouble lay in the magneto. The magneto was, therefore, removed from the engine and thoroughly examined, when it was discovered that the insulation of.the secondary winding had broken down at the Point where this wire passes through the collecting ring (see sketch). To, effect a repair was something of a problem. Even if insulating tape had been available—and it was not—it is doubtful if any use could have been made of it, as, owing to the high voltage, several thicknesses of the tape would have been required, and for this there was no room. 'However, it occurred to " W.31.C." that a little pure rubber melted on to the bare wire would serve the purpose. Fortunately he was able to procure, from a passing cyclist, a piece of valiie rubber tubing. This was melted on to the wire and moulded round it while in a plastic state, entirely covering the bare patch. The magneto was then assembled, the engine timed, and started on the first swing of the handle.
"A.31.D.," of Lanerk, makes an interesting suggestion as to a method of remagnetizing the magnets of a Ford magneto. It is also applicable, he says, to ignition apparatus of the ordinary OW. From a piece of sheet-iron, which may Is cut from a discarded oil tin or similar leceptaele, cut a piece 2 ins, wide and
51 ins. long. Fold this up as shown in the sketch into a casing 2 ins. by 2 ins. by a in. the extra quarter of an inch of material' overlapping, so that the ends may be soldered together. Then procure two other pieces of sheet-metal of the same kind, 3 ins, long and 11 ins. wide. Cut holes in the middle of each of these, 2 ins. by 1 in., and the resulting hollow rectangle will serve as flanges for the casing already made, to which they should be soldered.
Now procure 100 yds. of silk-covered wire, and wind it closely from end to end of the casing, leaving both ends free for connecting up to a source of current. This completes the remagnetizing coil; it, now requires current of 12 volts in tensity to energize it. This may be obtained either from three 4-volt or two 6-volt accumulators coupled in series.
Having fixed the coil on the bench, connect one end of the wire permanently to one of the battery terminal posts; place one pole of the magnet at the end of the coil, and connect the other end of the wire to the other terminal post of the battery. If the coil does not attract the magnet pole, place the other pole to the same end of the coil, and attrac tion will then be felt. The pole so attracted should then be placed inside the coil, and with battery and coil in circuit, and current flowing, withdrawn again. Break the circuit, replace the magnet 'pole. and repeat the foregoing operation three times. It will be found that the attraction between coil and magnet has considerably intensified. The same procedure should now be adopted with the other pole of the magnet, taking care to introduce it into the coil at the opposite end to that used for the first magnet. Remagnetizing is then complete, and if the magnets be tested, both before and after the operation, the difference in strength, and the increased efficiency of the magneto, will easily be apparent. The magnets should, be carefully keepered until they are replaced in their usual positions on the magneto. When replacing them take particular care to place like poles side by side, north by north and south by south.