Electrical problem

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Rob Buckland
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Last seen: 3 days 17 hours ago
Joined: 22/08/2019 - 08:28
Electrical problem

Hi

Let me start by saying this: My knowledge of electrics is close to zero (if I wire a plug and it doesn’t go bang!, I’m overjoyed).

I have no spark on my Villiers 4 stroke from an Atco 12 from 1962.

Points have been cleaned, and both surfaces now shine. Gap set. New spark plug. 

Flywheel removed, all cleaned up and replaced. Timing marks line up nicely.

Still nothing.

Do I start with changing the Condenser or should I do Condenser and Coil together? The coil looks quite yellowed on the wrapping.

Can I do some tests? I have a multimeter, but to be honest, it’s probably more intelligent than me.

Does anyone have a step- by- step guide for a duffer like me?

Any help would most welcome.

Rob.

 

 

 

 

wristpin
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Last seen: 6 hours 21 min ago
Joined: 23/05/2012 - 22:09
Set your meter to ohms

Set your meter to ohms/resistance touch one probe (doesn’t mater which colour) to the end of the plug ( HT) lead and the other to metal frame of the magneto - earth. That is measuring the resistance of the coil secondary winding. Expect a reading of between 5 and 7 ohms. What you don’t want to see is no resistance which suggests an internal short  or an open circuit suggesting a break in the winding. 

Then disconnect the wire from the coil to the points so that it is free from both the points and the condenser and take a reading between that wire and earth . Another resistance reading suggests that the primary is ok.

Those readings are indications , not dead certainties.

The condenser, the cheaper component, is best tested with a dedicated tester which will test its capacity to take a charge and hold it without self discharging. Testing with a multimeter, preferably analogue, is not as reliable - see Google / YouTube .

Expect to pay around £ 15 for a condenser and £70 for a newly manufactured coil from a reputable supplier such as  Meetens or Villiers Parts. ( Meetens are on Holiday for a week).

There are cheaper coils which may need modifications to their pole pieces to fit your stator and may be of dubious quality and age. Buyer be aware!