Bradford 'CA' starting/starter/electrics issue

[1942kemp1942]

Can anyone help with suggestions as to what might be the problem here ? Bought a restored 1946 'CA' last year. Seller described it as having a 'lazy' starter. When I press the starter the engine begins to turn over but doesn't complete a full revolution before stopping turning even though starter button is still pressed, I release the button and press it again and the engine then turns until it starts. This happens EVERY time I start it.

[Forumadmin]

Possibly a brush or winding issue on the starter or a problem with a worn starter ring. But first try a new fully charged battery and clean the battery, starter switch, starter and earth contacts.

You can check the electrical side by measuring the delivered voltage to the starter whilst it is trying to turn. It should be initially over 6v and then as the starter takes current perhaps drop by at the most 2 v.
If the voltage returns to 6v when the starter ' locks' up then it is likely a winding or brush issue. if it stays dropped to 4v or so then it is either the electrical connection or the mechanical side is locked or the starter is faulty.

I am assuming the starter is rated at 6v and not a 12 v one!

[1942kemp1942]

Going to re-check all these things over the next few days but what baffles me is why, having pressed the starter button and got a partial revolution of the engine, the second push of the button immediately turns the engine until it fires up. And yes, it's 6v.

[Forumadmin]

It may be stiction a bit like me getting up in the morning.
The cylinder will be full of fresh charge so fires on half a rev before battery runs out of puff but maybe there is enough inertia to rotate over any starter issue.

[1942kemp1942]

Been looking at it again. Battery appears to be OK. I have found that after pushing the starter button the pinion engages with the ring gear, engine turns less than a full revolution, then nothing, even though the button is still pushed down. The ammeter however continues to show a discharge even after the button is released. Pressing the button again then turns the engine until it starts without any clunk from the pinion engaging with the ring gear, so it clearly stayed in mesh after the engine stopped turning. Releasing the button returns the ammeter to mid-scale.
Noticed that after engine stops turning, if I 'juggle' with the starter button whilst keeping it pushed down, the engine will resume turning. By 'juggle' I mean that although I initially pushed it centrally, if I keep it pushed but move my finger to one side or the other, it makes the engine start turning again. So now wondering if there is a fault with the button ?

[Keith Clements]

You may be able to dismantle the button and clean the contacts.

[1942kemp1942]

Removed the starter button/switch, contacts slightly pitted but probably not enough to cause my problem. Cleaned them up but can't re-assemble the two halves since have no hollow rivets. Need 2 but have had to order 100 from China (!) to get 2. Won't be here for a couple of weeks but will see what happens when I re-install it.