BSA Owners' Club Forum

The BSA Workshop => Twins => Topic started by: Fereday on 27 May, 2017, 06:06:55

Title: No spark
Post by: Fereday on 27 May, 2017, 06:06:55
Bikes been starting and running good .then there was no spark at plugs I have a wassel electronic ignition how do you check power at coils thanks
Title: Re: No spark
Post by: Bess on 27 May, 2017, 08:21:16
Hi Fereday,
                  Hope this helps...

1 Check the battery has power
2 Using a test bulb or voltmeter/multimeter check for a power feed to the ignition module from
the ignition switch. Measure between the ignition feed wire and ground with ignition switch on
3 The voltage reading here should be the same as the voltage on the motorcycle battery
(12volts). If a significantly lower voltage is detected then this can indicate a faulty ignition
switch or a bad connection in the ignition circuit/wiring loom. A simple test is to take a direct
feed from the battery to the ignition pack, bypassing the normal feed from the ignition switch
1 Check wiring connections on black/white / black /yellow wires. Check for any visable signs of
damage on the stator plate and ensure the rotor is correctly located in taper seating
2 Using a multi meter check continuity through the stator plate. Set the meter to ohms. The
resistance reading for each coil should be 73 ohms. Connect the meter to the black/white &
black/yellow leads and the combined resistance should be 146 ohms
1 Check polarity of wires from the ignition module to stator (y/b to y/b & w/b to w/b). If these
wires are connected incorrectly ignition will produce a spark but the timing will be retarded
1 This indicates a poor supply to the ignition. Check battery for a bad cell. A bad battery with
charger connected can cause this problem
2 Check for good engine earth connection and battery earth point
3 Wrong type of ignition coil fitted with low primary resistance
Title: Re: No spark
Post by: Fereday on 28 May, 2017, 14:40:09
Done all the checks and it seems like I've fried the transistor box RJ33 because I was running on two 12 volt coils which gave too much amps does anyone now where I can purchase a transistor box  thank you
Title: Re: No spark
Post by: LIONELSMITH on 11 June, 2017, 20:11:49

It appears to be Wassell part number WW19375 (x2). 6 VOLT. You could try contacting Wassell and asking where you could buy. They seem to come in Positive and Negative earth so make sure you specify.

Contact them at