Getting the Atco Standard to start - advice, please.

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Adrian
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Getting the Atco Standard to start - advice, please.

I've just spent an enjoyable day at the Annual Rally being inundated with advice on getting my Standard running. It's spent twenty-odd years in a barn while I lived in rooms and flats where I couldn't keep a mower, and has suffered somewhat! Unfortunately I'm not there for the Sunday. However, if I can get it going before Bloxham... Suspicion is it's electrical, so I'm posting here for recommendations as to what I need to check and specs for things like multimeters.

The symptoms:

It will start and runs roughly for a few seconds before expiring again - compared to other Standards it sounds as though it's not firing on every revolution. Fuel is getting through OK - we've had the carb apart and checked the fuel filter as well. The clutch has freed up, and a bit of Plus Gas has loosened various other tight bits (oo er). The "sump" is dry as it should be. The points open, have been cleaned, and there is a spark (gap uncertain - no feeler gauge handy). The timing marks on the flywheel  are no more than a degree or two out from the one on the end of the crankshaft. Having checked with other MkVI-C engines today, maybe this is too good, as the range is between about ten degrees retarded to the same advanced!

So... what should the points gap be, please?

Plug is a Champion 7 - I believe the original spec was a 7Com, advice as to a modern equivalent, please? And the appropriate gap as well.

Testing the coil/condenser - testing electrics is a closed book to me, so any advice you can offer on the spec to use for multimeters etc, as well as what to do, would be appreciated.

Thanks!

Adrian

 

 

 

 

 

 

 

 

 

u

wristpin
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Joined: 23/05/2012 - 22:09
The 8 Com is no longer

The 8 Com is no longer available new but the equivalent is the D16, available from the Green Spark Plug Co.   I would avoid the NGK equivalent, the A6 as it just doesn’t seem to suit older engines.

In the absence of the “book figure” for the points gap , I’d settle for between 12 and 15 thou.

If you had no spark at all the first suspect would be old and corroded coil windings or a failed condenser. Even though you have some life in the sparks department this may still be the case but I’d start by removing the points and giving them a thorough clean and if they are pitted dress them on a fine slip stone.  When reassembling the points make sure that the two faces meet square . If they don’t a little tweaking can rectify the situation. Also mak sure that the moving point is  free on its pivot and not “ hanging” slightly.

New coils and condensers are available - at a price , the condenser being the cheaper component to try - I have 10 or 15  failed condensers removed from not quite so old engines in the last eighteen months alone !

if it comes to replacing the coil, be wary of some of the new old stock coils offered on auction sites . They may have suffered from as much internal corrosion while sitting on the shelf as though they had spent their time on a machine.

Fuel mixture. I believe in old oil for old engines; not modern thin semi or fully synthetic mixing oils, use a straight non detergent  30 or 40 grade motor oil at the correct ratio - 16 / 20:1 ?  Both Millers and Morris Lubricants both made a suitable Classic mixing oil.

Good luck!

Condenser graveyard!

Edit. Sorry, I ignored your question about testing.

Coil. You can check the resistance of the primary and secondary windings with a Digital Multi-Meter (DMM) but you need to know what they should be for your engine/coil.  Dedicated coil testers do stress the coil and where the coil is old and "on the edge", could just be the final straw!

Condenser, The only real test of a condenser is with a capacitance meter or a dedicated tester. It is possible DMM but there's also a risk of destroying the meter itself so my advice is DON'T!  New condensers are available for around £12 -15.

Condenser onr test

 

Adrian
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Joined: 16/06/2010 - 23:06
Thanks, Wristpin - I wondered

Thanks, Wristpin - I wondered if it would be you to reply first!

I'll get a couple of plugs, and I've unearthed my copy of The Villiers Engine by Browning that covers these early engines so I may well be able to get a figure for the points and plug gap from that. It might even have a resistance figure for the coil, though I think I'll have to convert from micro farads (I was reading it whilst exhausted last night, so it's not really lodged in any brain cells).

I'm using a "classic" oil at 16-1ish (the top line on the mix bottle is 25-1, so I've gone over it by some way), so that should be OK - should generate a decent blue fug, anyway. I'd have to hit the shed to check who made it - not Morris, anyway. It seems to spit a little from the aircleaner when conking out - is that a hint as to anything timing-wise, I wonder?

I will have to find the spanner I used to use for the flywheel next time I'm at Mum's, and nick iit, before I take it off - not doing that with an adjustable.

Despite the temptation to try to destroy a multimeter.... I think I'm a bit late for the Maplins fire sale! At the price for a new condensor that is probably worth the risk. Isn't there a club member who sells rewound coils? Not cheaply, but I can't imagine they are cheap to make in small numbers. I suspect that if the coil is so cranky it blows up under test, it was onto go anyway - is that right?

 

Sorry about all the questions, trying to get as many possibilities as possible all in one place so if I start the job I can (hopefully - old machinery is full of surprises) finish it.

Thanks,

Adrian

 

 

 

wristpin
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Joined: 23/05/2012 - 22:09
Ohms for resistance (coils)

Ohms for resistance (coils) and micro farads  for capacitance (condensers / capacitors)

Villiers used to do two versions of what were referred to as slogging spanners for freeing off or tightening the flywheel nuts. They were, and still may be,  available on eBay or from L and S  Engineers . 

New coils can usually be obtained from George Shead at Villiers Parts or Paul at Meetens. A club member put me in touch with a man who rewinds coils who said that he had a two month waiting list and would contact me  - he never did! 

Adrian
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Joined: 16/06/2010 - 23:06
That'll teach me to attempt

That'll teach me to attempt to read up on electrics in bed whilst knackered!

Thanks - I can remember being astounded as to what you could still get 25 years ago, so now I'm still astounded. I can see I need a little shop...

 

Adrian