Atco Standard 16” renovation.

14 posts / 0 new
Last post
UTC
Offline
Last seen: 2 weeks 4 days ago
Joined: 03/09/2020 - 12:28
Atco Standard 16” renovation.

Some time ago I bought this mower on the popular auction site and as so often happens it proved to be in worse condition than I had hoped. In fairness I don’t think the vendor realised the extent of this and indeed I did not pay a large sum for it.

It has a Villiers Mk VI C engine with an H prefix, which I think, dates it to 1923 and therefore is an early model. Even more reason to try to recover it. It has clearly been left very exposed out in the open for many years so that just about all the parts have rusted solid, including the engine. Some of the parts have rusted and deteriorated way past my skills of renovation but we’ll not worry about these at the moment.

After many weeks of working on the engine I have at last got it free enough to revolve.

Now for a few of what I think will be many questions. I have made some attempt to find answers by searching the forum but haven’t found exactly what I am looking for, however if answers already exist please do direct me to them.

1. As you can see from the picture the spark plug lead has disintegrated and I need to replace this. On the rear of the magneto back plate and passing in front of the spark plug lead connection there is a curved piece of wire which is attached to the backplate by a screw at each end. What is this?

 

2. On the other side of the backplate is what appears to be another connection to the magneto, see the picture below. What is this? The only things I can think of are a connection for lights but this seems pretty unlikely for a lawnmower! or some form of ignition cut-out.

 

3. The original Atco carburettor was still attached, see the picture below, but unfortunately is missing its float needle and float clip; the float itself is dented but useable I think. I’ve read somewhere on this forum (but now can’t find it) that unlike the clips on most Amal floats the clip on these is a separate part sitting on top of the float and upside down to the way they are fitted to Amal floats. Interestingly, inside the float chamber was the small brass ring, is this some part of the carb? What I’d especially like of course is another float needle but maybe one can be made. In order to get one made I need to know the diameter of the straight section (at the bottom of which is a cone shaped section which sits through the bottom of the float chamber to control the flow of fuel). Also the overall length of the needle (including cone section) and the distance of the groove (for the clip) below the top of the needle. The needle it seems protrudes through the top of the float chamber and is used to ‘tickle’ the carb. Incidentally, as a completely unrelated and nonsense question, why, when we tickle the carb do we keep pressing and releasing the tickler rather than simply holding it down until the carburettor floods?

 

4. The disc clutch plates are completely seized on the countershaft and I’ve not been able to find a drawing or picture of how the various parts are assembled. I’ve removed the outer collar by drilling through the retaining pin but I still can’t get anything to move, I guess I simply have to persevere with penetrating fluid etc or is there something I’ve not realised? Presumably the outer disc (the fixed disc) should now simply slide off the shaft? Also presumably the inner (sliding) disc should slide along the countershaft on a Woodruff key? I’ve poured diesel oil onto the friction plate (yes, I know it’s oil) but have been reluctant to try to drive a wedge between the two discs in order to help free them. Can someone tell me please which metal disc is the friction disc attached to?

Many thanks very much to anyone who can provide any help.

UTC

Adrian
Offline
Last seen: 1 hour 47 min ago
Joined: 16/06/2010 - 23:06
I can help with a couple of

I can help with a couple of these, as I fettled my magneto earlier this year.

1. That wire is a clip that holds the plug lead in place - see pic below. There's a groove in the end of the lead, and it sits in there. You can get a replacement lead here: http://www.villiersparts.co.uk/ignition.html - scroll well down the page until you get to the second row of HT leads and it's the one on the left. He sells everything you'd need to completely rebuild the mag - though probably way in excess of what your mower originally  cost!

2. Again, as you can see in the photo, I have the same place on my mag, fitted with a (rubber?) blank. My guess is that, as the engine would have been a proprietary item to be fitted to whatever, it was for eg lights or alternative HT lead placement should a customer company's machine need it. So you are not missing anything important. 

Can't help with 3 and 4, I'm afraid, as I have a Villiers carb and a drum clutch, but I hope that helps.

 

wristpin
wristpin's picture
Offline
Last seen: 3 hours 37 min ago
Joined: 23/05/2012 - 22:09
I’ve poured diesel oil onto

I’ve poured diesel oil onto the friction plate (yes, I know it’s oil) but have been reluctant to try to drive a wedge between the two discs in order to help free them

At this stage I think that it is more important to dismantle without breaking anything, so I have a 25 litre drum of red diesel  ( big enough to fully immerse a Marquis rear roller) and leave things to soak , sometimes for a week or more - very effective !

UTC
Offline
Last seen: 2 weeks 4 days ago
Joined: 03/09/2020 - 12:28
Thank you very much Adrian

Thank you very much Adrian for your helpful response and the link. I take it you are referring to the plug lead described as "Original Villiers HT lead, push in type.

I want this mower to be a usable machine and not a shiny exhibit so I'm very keen to get the engine running and a spark plug lead is pretty essential! Let's hope the ignition coil doesn't need replacing, it will spoil the pleasure of renovating this mower if it requires large sums of money spent on it.

I believe this 147cc engine was primarily used in small motorcycles and the Villiers Parts Book does show a lighting set was available for it so you are likely correct that the second hole in the backplate was to provide a connection to lighting coils. I'll seal it with some black silicone sealant.

Thanks Wristpin, unfortunately I don't have a 25 litre drum of diesel, however the clutch friction plate has been saturated and regularly topped up with diesel not for just a few days or even a week but for several weeks. I've kept the disc oiler filled with PlusGas and continually apply this to the shaft and end of the fixed disc.

I have a puller attached to the sprocket on the fixed disc and periodically apply heat to the shaft with a blowtorch but the disc shows absolutely no sign of moving. This is why I increasingly wonder whether there is something I've misunderstood or need to know about dismantling this clutch.

I really don't want to resort to the malicious use of a large hammer and damage a 100 year old piece of machinery.

UTC

Adrian
Offline
Last seen: 1 hour 47 min ago
Joined: 16/06/2010 - 23:06
Yes, that's the one - if you

Yes, that's the one - if you look closely (very, it's a tiny pic!) you'll see it's got the same shaped end at the right angle - by the 1930s, they were screw-in.

Adrian
Offline
Last seen: 1 hour 47 min ago
Joined: 16/06/2010 - 23:06
Dunno if this helps? with any

Dunno if this helps? with any of your enquiries?

https://www.oldlawnmowerclub.co.uk/forum/general-topics/general-discussi...

UTC
Offline
Last seen: 2 weeks 4 days ago
Joined: 03/09/2020 - 12:28
Very many thanks again Adrian

Very many thanks again Adrian and my apologies for the slight delay in acknowledging your help.

Yes indeed, this does help. Although we don’t actually see him remove the fixed clutch disc after drilling out the taper pin and removing the collar (which I have done) I would imagine he would have shown any other significant steps before getting to the clutch sliding disc.

So I guess I must just persevere with what I’m doing before getting a larger hammer!

UTC

 

UTC
Offline
Last seen: 2 weeks 4 days ago
Joined: 03/09/2020 - 12:28
I've been checking back

I've been checking back regularly to see whether anybody had any advise but unfortunately not. In the meantime I’ve been persevering and by trying a number of different techniques have at last managed to free the clutch plates on the shaft and remove them without damage. That’s a relief!

I’ve realised that the clutch friction disc is surely the original 100 year old part and appears to be asbestos so I’ll keep it carefully wrapped up until refitting it.

Thanks to Adrian’s advice I’ve bought a replacement HT lead from George Shead. This was a genuine NOS Villiers item; it must be a few years old.

Unfortunately the spark is extremely weak despite having cleaned and reset the points and will certainly never run or start the engine. I’ve read on this forum that this is almost certainly due to a deteriorated ignition coil. However I’ve also noticed that the magnets in the flywheel don’t appear to be very strong, is that normal? Maybe I should try to get the flywheel re-magnetised?

Ideally I should take the unit to an expert to have the whole ignition system checked but I’ve not found anybody who can undertake this on these 100 year old ignition systems. In the meantime I’ve read that the Resistance of the Ignition Coil Secondary Winding should be in the 3K to 5K range and in testing mine I find there is not even continuity so presumably the wires have probably corroded through. Apart from any other problems then it seems I need a replacement coil; I’ve read the warnings related to the purchase of NOS ignition coils and the price of good replacement coils!

UTC

 

wristpin
wristpin's picture
Offline
Last seen: 3 hours 37 min ago
Joined: 23/05/2012 - 22:09
I’ve never found the need to

I’ve never found the need to have a flywheel remagnetised but I believe that Villiers Services  ( not Villiers Parts) do offer that service. I would treat remagnetising as a last resort after fitting a new coil and condenser. Avoid  suppressed plug caps and resistor plugs.

It has been my experience that many old engines run satisfactorily while only exhibiting what by modern standards is a fairly puny spark. 

 

Adrian
Offline
Last seen: 1 hour 47 min ago
Joined: 16/06/2010 - 23:06
I'm more than happy to offer

I'm more than happy to offer assistance - there's a whole thread of it round here somewhere! 

Most of it was surprisingly idiot-proof, though you do need to watch exactly where the insulated bushes in the points box go - they had me beat for a while.

UTC
Offline
Last seen: 2 weeks 4 days ago
Joined: 03/09/2020 - 12:28
Thanks for your thoughts

Thanks for your thoughts Wristpin. The spark plug is an 18mm dismantlable non-resistor plug which I’ve taken apart and thoroughly cleaned. To give it the best chance the HT lead is screwed directly to the terminal. I’ve tried a range of spark plug gaps and even EasyStart yet I can’t get it to fire even once.

I understood the fact there was no circuit through the secondary winding pretty much confirmed the coil had failed.

I’m surprised people suffer so much from failed condensers, despite their age. From my experience old capacitors were of much better construction and reliability than the cheap items available today. I don’t remember them being a particular problem on old two stroke Villiers engined motorcycles.

I appreciate what you write about these simple old engines not needing the strong high voltage spark that modern petrol engines require. Back in their day petrol would have been very low octane and compression ratios were equally low, they even had to run on pool petrol in the 40’s.

Thanks Adrian, you’ve already been a great help. I’ve read through your many extensive postings on ignition problems, in particular ‘Getting the Atco Standard started’ which began in May 2018 and have learned a lot from these. Yes, it’s clearly important to get those little insulating washers in the correct place, also to make sure they’re not cracked, broken or deformed.

 

wristpin
wristpin's picture
Offline
Last seen: 3 hours 37 min ago
Joined: 23/05/2012 - 22:09
I’m surprised people suffer

I’m surprised people suffer so much from failed condensers, despite their age. From my experience old capacitors were of much better construction and reliability than the cheap items available today. I don’t remember them being a particular problem on old two stroke Villiers engined motorcycles.

In the course of a year I often work on over a dozen small engines, both two and four stroke and probably condemn up to seventy five percent of their condensers.  I’m fortunate to have a proper old school ignition tester with a dedicated condenser test function which will test a condenser’s  ability to take a one shot charge to full capacity , hold that charge and then discharge it fully - what is needed on an engine running at anything between three and five thousand rpm. Failure to take a charge or to hold it  is a misfire on a running engine ; may be an obvious misfire detectable by ear or a not so obvious one that results in incomplete combustion of the fuel air mixture and gives rise to a lot of fiddling with the carburettor .

My tester will identify totally dud, iffy and good condensers . Nothing other than 100% good leaves my bench; saves a lot of time and angst in the long run. Nothing worse than an engine that starts playing up after a few minutes running, having started apparently healthy.

Remember VICtor , which stands for Valves, Ignition, Carburettor - in that order; saves a lot of messing about.

UTC
Offline
Last seen: 2 weeks 4 days ago
Joined: 03/09/2020 - 12:28
How very interesting Wristpin

How very interesting Wristpin. I find this extremely surprising and good to know. 75% is an extremely high percentage.

You clearly speak from considerable experience and it sounds as though they should be replaced as a matter of routine as almost none of us are able to check whether we have the one in four good ones.

I'd always understood and my limited experience showed these old condensers were typically reliable, unlike the cheap modern replacements, and only tended to fail after running for some time and having warmed up.

Thanks for that.

 

wristpin
wristpin's picture
Offline
Last seen: 3 hours 37 min ago
Joined: 23/05/2012 - 22:09
Most of the engines that I

Most of the engines that I work on are definitely vintage and in a good few cases have spent time in the open and are sorely neglected. White corrosion and even spider’s eggs in flywheel magnetos are not unusual so perhaps I’m a glutton for punishment . Expect the worst and try to get the job right the first time .

Here's one I did earlier - as they say. Been sitting partly covered at the end of a garden for at least ten years!