TESTING FOR COMMON CHARGING AND NO SPARK PROBLEMS ON BRITISH BIKES WITH ALTERNATORS AND BATTERY/COIL IGNITION, NON DISTRIBUTOR TYPE.
CHARGING
PROBLEMS: TEST STATOR FOR CONTINUITY
BETWEEN BOTH WIRES AFTER UNPLUGGING
FROM RECTIFIER. YOU SHOULD THEN CHECK FOR CONTINUITY
TO
ENGINE CASE. YOU SHOULD HAVE NONE.
IF STATOR IS OK, CHECK ROTOR FOR
LOOSENESS ON SHAFT AND IF OK, REMOVE FROM CRANK AND TEST MAGNETISM. A CRUDE TEST
CAN BE MADE BY ATTEMPTING TO PICK IT UP
WITH
A SCREWDRIVER FROM YOUR WOODEN
WORKBENCH BY EACH OF THE SIX MAGNETIC POLES. A NEW STATOR TAKES APPROX. 16
POUNDS OF PULL ON EACH MAGNET TO PULL IT OFF OF A METAL SURFACE, AND CAN BE
ACCURATELY BE CHECKED BY TYING A STRING THROUGH THE HOLE AND PULLING IT OFF THE
TOP OF A BENCH VICE ANVIL WITH A FISHING SCALE, ON EACH OF THE SIX MAGNETS.
IF IT FAILS THIS TEST BY MUCH,
OR IS
LOOSE ON SHAFT, REPLACE. CHECK RECTIFIER FOR CONTINUITY ACROSS EVERY
PAIR OF
TERMINALS BACK & FORTH. YOU SHOULD
ONLY GET CONTINUITY IN ONE
DIRECTION!
SPARK PROBLEM: UNPLUG POINTS WIRES FROM
COILS. TEST FOR CONTINUITY FROM EACH
POINTS WIRE TO GROUND WHILE KICKING OVER BIKE. IF IT DOES NOT
MAKE AND BREAK CONNECTION TO GROUND, REMOVE NUT ON EACH
SET OF POINTS HOLDING POINTS WIRE
ON, AND REASSEMBLE AS FOLLOWS ON THREADED STUD FOR EACH SET OF
POINTS:
INSULATING WASHER, POINTS SPRING, POINTS WIRE, INSULATION WASHER,
NUT.
TRY AGAIN. IF YOU THEN GET INTERMITTENT CONTINUITY AS YOU ROTATE
ENGINE,
MAKE SURE THE POINTS FOR EACH CYLINDER ARE JUST OPENING AS THAT
PISTON IS APPROACHING TOP DEAD
CENTRE ON COMPRESSION STROKE. OF COURSE, BEFORE GOING
RIDING, MAKE SURE POINTS GAP FOR EACH SET OF POINTS IS CORRECT
WHEN THE ADVANCE CAM SCRIBE MARK IS LINED UP WITH THE
POINTS "HEEL", THEN CLEAN EACH SET OF CONTACTS OFF WITH
SURFACES INSIDE THE ADVANCE UNIT) SHOULD ALL BE CLEAN AND LUBED
WITH DISTRIBUTOR GREASE.
CHECK WITH STROBE LIGHT AFTER YOU START BIKE TO MAKE SURE TIMING MARKS IN PRIMARY CASE LINE UP AT 3000 RPM AND MOVE BACK TO RETARDED POSITION WHEN ENGINE IDLES. IF YOU HAVE NO TIMING MARKS IN PRIMARY CASE, CONTACT US (OR BUY A COPY OF "MODERN MOTORCYCLE MECHANICS" ) TO GET THE DISTANCE BEFORE TOP DEAD CENTRE ON COMPRESSION STROKE THE PISTON SHOULD BE LOCATED AT (MEASURED THRU THE SPARKPLUG HOLE) WHEN YOU TURN THE ADVANCE CAM AGAINST SPRING PRESSURE AND ADJUST THE TIMING ON EACH SET OF POINTS TO JUST BE BREAKING AT THE END OF THE TRAVEL OF THE ADVANCE CAM, BEFORE ROTATING THE ENGINE A FULL TURN ON A TWIN TO SET THE OTHER SET OF POINTS.