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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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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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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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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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

 

 

Adrian
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Well, it's only taken a year

Well, it's only taken a year to fit a new plug and get back here, good job there's no hurry! As you can probably imagine the mower didn't make Bloxham - last year or this - but I did get a nice Atco spanner off of Keith.

The spark with the new plug is pathetic, so it's time to investigate the condenser and the coil. Condenser first as it's cheaper (think mortgage).

 

Adrian

Adrian
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Righty ho, new Condenser

Righty ho, new Condenser purchased! To my amusement, George Shead lives somewhere I used to know quite well, had an aunt and uncle just down the road from him.

 

Next idiot question - how do I get it out? I have a spare points box and as far as I can see there are two bolts holding it on to the back plate of the mag that pass through the "ears" of the condenser. Is this one of those things where I need to take the nuts off the remove the points box, then put them back to unscrew the bolts through the ears? Browning's book is less than helpful on this point - obviously condensers didn't go pearshaped in his day.

Thanks.

Adrian

 

gtc
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The condenser should be a

The condenser should be a little square thing mounted behind the points:

https://i.pinimg.com/474x/54/b7/00/54b700d3dde30f61c1f49082fbc6c373.jpg

 

 

 

atcocrazy
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If you are fitting the

If you are fitting the original style of condenser in its original position, then you need to remove the stator/coil backplate after the flywheel is off. This will be held either with straps to the engine or bolt in the centre depending on which Villiers 2 stroke engine is fitted, also by the boss in the centre so having removed the above you can twist off.

Once that is off you can remove the nuts and studs holding it in position.

The alternative would be to disconnect the original condenser wire from the coil and moving contact terminal, other styles like the cylindrical type used on cars can be mounted and grounded somewhere suitable, such as the exterior of the backplate, then the wire from this substituted for the one on the old condenser.

I think theres some people now selling the original style for around £10-14 but there's a little more work replacing them.

Hope this helps, think i could have fixed by the time it took to write this lol.

Best regards

 

Steve Smith

atcocrazy
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On reflection, if replacing

On reflection, if replacing the original condenser, you will have to weigh up whether the backplate has to come off to remove the circular points/condenser box, it's just that I find it easier that way. This box will have to come off since the condenser lives (if it is not already dead) sandwiched between the recess at the rear of the box and the backplate.

Adrian
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Thanks, Steve. Now to fit the

Thanks, Steve. Now to fit the job round crickt and gardening...

Adrian

 

Adrian
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Righty-ho - having a bit of

Righty-ho - having a bit of spare cash (if anyone reads Amateur Photographer, and saw the recent article on box cameras... that's where the cash is from!), I've just ordered a new coil for my Standard. Well, they're promiscuous little buggers, and the last thing you want is to find a shed full of baby mowers...

So... a word to the wise. I will most likely be appearing here again with idiot questions, or at least questions born out of ignorance, again. Beware!

Adrian

 

Adrian
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OK, this one really is from

OK, this one really is from the Dept of Stupid Questions.

Just how dark does it need to be to see the spark from a spark plug? I've no visible spark, having gone right through the mag and replaced the coil and condenser. The plug is new, I have continuity in my plug lead (I am assuming, as seems reasonable, that zero resistance means that the wire is intact), and I have continuity through to the coil. I suppose I should check whether this changes when the points are open or closed?

I thought I'd check the plug in my usual mower, testing the plug against one that I know works, and I couldn't see a spark there... but when I replaced the plug, it fired! I'm a bit mystified as I've replaced the condenser and the coil, I have continuity all the way through from the condenser box to the plug when the points are closed and lose it when they are open, so the circuit seems OK...

 

Adrian
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...and the points gap poked.

...and the points gap poked. Still nothing!

wristpin
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For what help it is, my

For what help it is, my experience of ancient Villiers is that they need immaculate points , closing squarely,  and spot on timing. Even finding a true top dead centre can be a fiddle , whether by a screwdriver through the plug hole or even a DTI , there’s always that “ swishy” bit between up and down.  The only totally accurate way is with the positive stop method and a timing disc.

 

 

 

Adrian
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That's just it - the points

That's just it - the points are clean, no pits, they meet as square as I can make them (that has meant some poking). Nothing. I don't think an engine as basic as the Mk VI-C can be that fussy timing-wise, as the other ones I checked at the 2018 AGM had timing marks all over the shop. I've even rubbed down a bit of metal on the cylinder to give a good earth, checked it with the multimeter, nowt. And surely, even if the timing is out, I should get a spark?

What worries me is that Wristpin appears to be beat - it must be bad! I'm utterly at a loss, having spent over 80 quid on parts I'm a bit cheesed off with the thing. It's gone back in the shed accompanied by swearing. Later on I'll compare the before and after pics in case I can spot something stupid I've done, but right know I shall chuck it in the phuckit bucket for the day.

 

wristpin
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I’m not “ beat” as you put it

I’m not “ beat” as you put it , you are the man on the spot. The difficulty with offering advice on line is that one is having to assume that everything is as described or as expected ; is that insulating washer or top hat bush correctly positioned and is the timing correct? You comment about timing marks “ being all over the shop” . May be a non original flywheel  and the owner has found what works.  I’m no Villiers expert but I have found that they have used different methods of marking their flywheels. Some require  the engine to be turned and the btdc to be measured and set every time the flywheel is removed while others have a timing mark the misses out the measuring stage but just requires the piston to be set to TDC and the flywheel set to that - the factory have simplified the job for future servicemen or repairers.

Go through everything again, check and recheck

 

 

 

 

Adrian
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Sorry, I think I let my

Sorry, I think I let my frustration spill over a bit. My apologies

Definitely no spark - I tried in the shed in the near dark, and it was so sparkless that I even risked holding the plug spade and cranking. Not a tingle.
The fact there's so little in the mag to go wrong is bugging me. Most of it, like the two top hat bushes in the breaker assembly (now I know what one of those is!), can really only go in one place that I can see. Please tell me if I am wrong but surely even if the timing is out there will be a spark when the contact is broken? I can understand why it might not run if the spark is at the wrong stage in the cycle but I can't see how the timing affects *generating* a spark, unless it's so far out that the electrical charge hasn't been generated. I know it's a lot of questions, but I'm trying to get my head round what's going on and electrics are very definitely not my thing.

I take your point about the flywheels. On the MkVI-C engine, you have to reset it every time you remove the flywheel - years ago it refused to start, having been running quite sweetly, and it took me a long while to twig that it had backfired when I stopped it, and the flywheel had moved about a quarter of a turn! Mine has matching numbers, so is presumably original, but that doesn't mean any of the others I looked at did.

I'm told that the HT lead may break down at spark loads even if it's OK when not loaded - given that the lead is elderly, maybe even original, I think that will be my next port of call, and I'm seriously considering finding a bit of new wire to replace the one between the points and the coil.

Watch this space...

 

wristpin
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The copper core of the HT

The copper core of the HT lead is unlikely to fail and a simple continuity test will determine that, but if it’s insulation is hard and crispy the high voltage may well track out and find an easier path to earth than the plug gap. If your lead has the Bakelite screw in fitting to the back of the mag and the little spring loaded plunger contacting the back of the coil you can, with care, renew just the lead, but the whole assembly is available from the likes of Villiers Parts. 

If renewing the lead you need to carefully stretch the spring slightly and insert a thin “ electricians” screwdriver between the coils to undo a small brass wood screw that secures the spring to the end of the lead.  A bit of a fiddle but doable. The main issue may be obtaining a suitable length of copper cored “rubber”  covered HT cable.

http://www.villiersparts.co.uk/ignition.html

 

Adrian
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Wristpin speak wise words,

Wristpin speak wise words, Grasshopper!*

Eventually discovered that the lead from the coil was on the wrong side of an insulated bush and lo! A spark! I need a feeler guage for the plug gap, but it is enough to get it to start and run for a few seconds, even on elderly petroil. That's the best I've had in at nearly 20 years. I'm going to the clean the carb up next and clean out the fuel line, and maybe get a new throttle cable as the old one is flaccid enough to always be resting on something it shouldn't be.

*Bounces off wall!*

*Grassboxer?

Adrian
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Sure I'd posted this already.

Sure I'd posted this already... must have pressed the wrong button. 

https://flic.kr/p/2jov74y

It lives! Eventually realised that the flywheel was still slipping - it can take a LOT of tightening, sorted the timing by trial and cursing, and off it went. Seems a bit fast - maybe the later carb is over-delivering mixture? - but it runs and cuts, though the roller is prone to slipping despite its substantial weight.

 

 

gtc
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Thanks for the video. Great

Thanks for the video. Great to see and hear.

Two-strokes tend to run flat out for power. I used to run behind my father's Atco as a kid. The trick was to stop and turn it before slamming into the sandstone raised garden beds and being yelled at. :-)

wristpin
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Just revived a 1954 machine

Just revived a 1954 machine and that is fairly swift. Fortunately with a nice sharp cylinder and bottom blade the engine is quite happy to run at little more than idle so the machine is manageable for a mature pilot!