BSA Motorcycles 1950s

FITTING INSTRUCTIONS FOR K-TEC 6-VOLT ELECTRONIC REGULATOR

Introduction: [1]

The K-Tec 6 volt is a solid-state voltage regulator, for motorcycles equipped with a Lucas 6 volt dynamo charging system. The regulator must not be used without a battery, as this may damage it!

Step 1: Ensure that you have the correct version of the K-Tec 6 volt regulator depending on whether your motorcycle is negative or positive earth.

Step 2: Disconnect the battery, remove the earth connection first.

Step 2: Remove the dynamo control box from the motorcycle by releasing the two fixing nuts from either end, unscrewing the connector plate and unplugging the wires from underneath.

Step 4: Remove the top cover from the control and take out the two relay units by unscrewing them from the base unit and cutting the wires. Also remove the wire wound resister from underneath the base unit.

Step 5: Fix the K-Tec regulator down to the base unit using the bolt protruding from the bottom, and the existing hole in the base unit. On some versions you may have to drill a new hole.

Step 6: Solder the wires coming out of the top of the K-Tec regulator to the solder tags on the top-front of the base unit. The color code is listed in the table below.

Step 7: Refit the control box to the motorcycle. Reconnect the battery, connecting the earth terminal last.

NEGATIVE EARTH POSITIVE EARTH SOLDER TAG DEFINITION

GREEN BLUE F DYNAMO FIELD

RED BLACK A BATTERY LIVE

YELLOW YELLOW D DYNAMO OUTPUT

BLACK REDE EARTH [FRAME]

NOTE: THE MOUNTING STUD HAS NO INTERNAL CONNECTION AND NEED NOT BE EARTHED.

TROUBLE SHOOTING [WHAT TO DO IF IT DOESN'T WORK]

1: Check that you have the correct version of the regulator depending on whether your motorcycle is positive or negative earth, 6 volt or 12 volt.

2: Ensure that you are using a healthy battery and check through all the wiring and connections paying special attention to the D and F terminals on the back of the dynamo, making sure that these are not shorted together and are the correct way around.

3: If your dynamo has been rebuilt or you are unsure as to its polarity the procedure for re-magnetizing it is as follows:

Disconnect the wires to the dynamo and using a length of spare wire "FLASH" [just make the connection for a couple of seconds] the F terminal on the dynamo to the live battery terminal [the opposite terminal to the one connected to the motorcycle frame]. This will re-magnetize the metalwork in the dynamo with the north and south poles the correct way around.

4: To test the dynamo output on the machine. Disconnect the wires on the terminals on the dynamo and using a short wire connect the D and F terminals together, then connect a 12 volt bulb [or a volt meter] between the link and ground [motorcycle frame]. With the engine running at a moderate speed, the bulb should glow brightly [a volt meter should read between 14 and 20 volts].

5: To motors test the dynamo on the bench. Using a short wire join the D and F terminals on the dynamo, then connect a good 6-volt battery between the body of the dynamo and the link. FOR A POSITIVE EARTH SYSTEM CONNECT THE POSITIVE OF THE BATTERY TO THE BODY OF THE DYNAMO, AND THE NEGATIVE TO THE LINK. FOR A NEGATIVE EARTH SYSTEM CONNECT THE NEGATIVE OF THE BATTERY TO THE DYNAMO AND THE POSITIVE TO THE LINK.

The dynamo should then work as a motor and rotate in the direction it would in the bike, if it runs in the opposite direction then the connections to the ends of the field winding inside the dynamo should be reversed. If the dynamo fails to turn or runs erratically professional advice from a dynamo specialist should be sought.

6:If the regulator appears not to regulate. To test whether the regulator is working correctly measure the voltage across the battery with the engine running at a moderate speed [2000 to 3000 rpm] a reading of 7-7.5 volts on a 6 volt system, or 13.5-14.5 0n a 12 volt system indicates that the unit is OK. If the battery voltage is to high check that the regulator has a good earth connection.

The K-Tec regulator is a sealed solid-state unit and cannot be tested off the bike without the use of specialist equipment. If then unit is suspected of being faulty it should be returned to K-Tec for testing.

Notes. 1. Apologies, diagram/s have gone astray. Ed.