Condenser Missing?

[Hancock]

Hello

I have recently bought A BSA B40 1962. I am having troubles with the ignition, the bike runs if I keep the revs up on the throttle.
It looks like I am missing a condenser within the distributer comparing it with the manual. Is this the case? what does it do?

Thank you
Clive

[AWJDThumper]

Yes - the condenser should be bolted on to the threaded pillar at the top and connected to the input terminal on the left. The condenser stops all the energy stored in the coil arcing across the points when they open. Without it, most of the energy is lost in this way rather than generating a high voltage which discharges across the spark plug gap.

[Hancock]

Thanks it looked like there was something missing. The bike fired up but would not run.Does anyone know which condenser I need . Save me ordering the wrong one. Thanks again.

[AWJDThumper]

This is the type you require but try contacting one of the UK suppliers to see if they have one (Feked, Dragonfly, Burton Bike Bits, etc):

https://www.ebay.co.uk/itm/NOS-Lucas-421327-Condenser-1960-1962-Triumph-w-Lucas-15D1-Distributor/322873274942?hash=item4b2cbf323e:g:lUcAAOSwA~VaBL1N

[JulianS]

I would be suprised if the bike would run without the condenser fitted.

It could be remotely mounted - it is just connected in parallel with the points - between the input terminal to the distributor and earth. It was not always easy to find the appropriate one to fit inside the distributor and owners improvised. Follow the wires from distributor and you may find it.

[AWJDThumper]

I think the bike will still run without the condenser and will probably do what you've experienced because the coil energy lost across the points will reduce with higher revs - this is simply because the time the point's gap is very small (which is when the energy is lost) will reduce. The condenser needs to be mounted as close to the points as possible - if it was mounted near the coil it would still probably result in arcing across the points and poor running.

[JulianS]

Bikes fitted with the 6CA points assembly, fitted to BSA unit singles and twins from around 1967,  had remote mounted condensers - there was just not enough room for one on the new design points assembly.

[Hancock]

Thanks for your comments and knowledge .ive had a look and there is no condenserI’ll source one from somewhere.

[phill]

Hi, - interesting. As you know I'm having misfiring problems. My condenser is fitted remotely near the coil. Please explain why it needs to be near the points - I haven't heard this before.

Many thanks,
Phil

[Hancock]

Hello. I’ve put a condenser in the distributor. The bike will only run if I keep reving the engine  and there’s quite a bit of arching at the points,? The bike also misfires quite a bit ?

[AWJDThumper]

If you didn't have a condenser connected before, you would have got a very weak spark. If you've now fitted a condenser and it hasn't made a difference to how the engine runs, I would double check the condenser is doing what it should be. To check, you can do the following:

Take out the plug and connect it to the HT cap and earth the threads against the bare metal of the engine. Rotate the engine so that the points are closed and switch on the ignition. If you then open the points with a screwdriver, or preferably something made of plastic, you should then get a spark at the spark plug. If you disconnect the condenser it will change the spark produced from a healthy one to a weak one which may be difficult to see. If disconnecting the condenser doesn't produce this change, it's not doing its job either because it isn't connected correctly; it's the wrong polarity condenser or it simply doesn't work.

[ducati2242]

If you didn't have a condenser connected before, you would have got a very weak spark. If you've now fitted a condenser and it hasn't made a difference to how the engine runs, I would double check the condenser is doing what it should be. To check, you can do the following:

Take out the plug and connect it to the HT cap and earth the threads against the bare metal of the engine. Rotate the engine so that the points are closed and switch on the ignition. If you then open the points with a screwdriver, or preferably something made of plastic, you should then get a spark at the spark plug. If you disconnect the condenser it will change the spark produced from a healthy one to a weak one which may be difficult to see. If disconnecting the condenser doesn't produce this change, it's not doing its job either because it isn't connected correctly; it's the wrong polarity condenser or it simply doesn't work.

Excellent advice .

[Hancock]

I’ll give that a go thanks

[Dean Southall]

I have been using the Brightsparks Easycap condenser in my bikes and have been very pleased. As well as beening solid state they are very compact.
http://brightsparkmagnetos.com/easycap/

[AWJDThumper]

I think the jury may still be out on whether these ceramic multilayer capacitors are reliable in the longer term for this type of application. Brightspark's recommendation for replacing them after 4 years or subjecting them to high voltage capacitance testing after 4 years and every year thereafter doesn't inspire a huge amount of confidence, especially as normal electrolytic capacitors last many years longer. For magneto use, it is a different matter because they provide a very neat way of accommodating the capacitor.