CONTACT BREAKER

Hawera Star, Volume LIII, 10 June 1933, Page 12

CONTACT BREAKER

VITAL PART OF COIL SYSTEM. The contact breaker points are the most vital part of the coil system and need rather more care in adjustment. The majority of failures are due to some small fault in the points. Owing to the low low-tension voltage (12 or six volts) any electrical resistance m the points will cause complete failure to generate a spark. The contact breaker gap should not exceed 0.012 in. Any increase m this gap reduces the time during which the contacts are- closed, so .preventing a proper “building-up” of voltage m the primary winding of the coil. Considerable pitting occurs after a time; usually a. hollow appears in one contact, while the other builds u.p a little pip which fits neatly into the hollow when the points close. Hus is clue to deposition of metal oft one contact on to the other owing to the fact that the current always flows in one direction through the points 1 here is no reversal of current each half revolution as with a magneto. This particular form of pitting can be left alone for some time provided the points are not adjusted or altered in any way. When the pit or hole has become' very deep, however, it if. advisable to renew the pitted contact and to true up the other one. In the event of ignition trouble the points must, of course, be trued up and adjusted at once.