Help - Lawnmower!
Discussion
Ok white flag time, I am struggling. It’s a vintage Atco with a 4 stroke Villiers engine - I think it dates back to the mid sixties.
I’ve owned it since 1992 and have become rather attached to it. It had been running rough for a while (cutting out when hot). I thought it could be the exhaust valve sticking shut as when you cranked it white / grey smoke was coming out of the air filter.
I took the cylinder head off and it was badly coked up. I cleaned it all up and it hasn’t run since despite all my efforts and time.
It’s had a new contact breaker points fitted, gap set correctly, carburettor is as clean as whistle, it is sparking and getting fuel.
It does sort of cough when cranking, and I was seeing the white / grey smoke emitted from the air filter.
I’m absolutely baffled, any advice would be very welcome.
I’ve kept this old mower going for over 30 years with the odd bit of tinkering now and again. But this time it’s got me stumped!
I’ve owned it since 1992 and have become rather attached to it. It had been running rough for a while (cutting out when hot). I thought it could be the exhaust valve sticking shut as when you cranked it white / grey smoke was coming out of the air filter.
I took the cylinder head off and it was badly coked up. I cleaned it all up and it hasn’t run since despite all my efforts and time.
It’s had a new contact breaker points fitted, gap set correctly, carburettor is as clean as whistle, it is sparking and getting fuel.
It does sort of cough when cranking, and I was seeing the white / grey smoke emitted from the air filter.
I’m absolutely baffled, any advice would be very welcome.
I’ve kept this old mower going for over 30 years with the odd bit of tinkering now and again. But this time it’s got me stumped!
At the risk of arms-length diagnosis, your original issue was likely a breakdown of the internal insulation in the coil. The most obvious symptom being cutting out when hot. Of course, you may, or may not, have introduced other issues when dismantling.
In all honesty, these side valve engines are simple, robust and reliable and will run for years on little or no maintenance. Basics; you need a good spark (preferably at the right time), fuel (spark plug wet?) and compression (you put a new head gasket on right?). Check also that the air filter/intake is not clogged with grass.
You can likely get a new coil (and probably points) from here http://www.villiersparts.co.uk/
In all honesty, these side valve engines are simple, robust and reliable and will run for years on little or no maintenance. Basics; you need a good spark (preferably at the right time), fuel (spark plug wet?) and compression (you put a new head gasket on right?). Check also that the air filter/intake is not clogged with grass.
You can likely get a new coil (and probably points) from here http://www.villiersparts.co.uk/
Valves sticking open, or burnt is a possibility?
I'd think that looking at the carbon in the combustion chamber, the exhaust valve would want a clean and the tappets set.
The ignition side of things is always suspect.
I've seen men get cross when after hours of labour and ££ of parts, fresh petrol does the trick.
Over the years, the engine that stumped most people for longest wasn't getting any air, because the airfilter had been assembled wrong.
Another outside possibility is the valve timing has slipped.
Just check everything from first principles until it works.
I'd think that looking at the carbon in the combustion chamber, the exhaust valve would want a clean and the tappets set.
The ignition side of things is always suspect.
I've seen men get cross when after hours of labour and ££ of parts, fresh petrol does the trick.
Over the years, the engine that stumped most people for longest wasn't getting any air, because the airfilter had been assembled wrong.
Another outside possibility is the valve timing has slipped.
Just check everything from first principles until it works.
Hi Fly, and thank you.
It did run briefly after the de coke, then I realised that the thread for the spark plug was poor, so I had a spare cylinder head and fitted that. It’s a composite gasket, copper and asbestos, I just re used the same gasket but torqued up correctly.
It’s not run at all since I swapped heads, I do have a new gasket (non copper / asbestos) so it maybe related and it might be an idea to fit.
The coil, yes I did suspect this, I’ve done a resistance check and it’s ok - when cold though..
Air filter very clean, fuel is wetting the plug, I’ve had a volt meter on the spark plug lead and it’s getting voltage at the plug end - and I’ve tried few different plugs.
As you say, these things run for ever, or it has done up until now.
I think it might be a good idea and take the head off again and start from there.
It did run briefly after the de coke, then I realised that the thread for the spark plug was poor, so I had a spare cylinder head and fitted that. It’s a composite gasket, copper and asbestos, I just re used the same gasket but torqued up correctly.
It’s not run at all since I swapped heads, I do have a new gasket (non copper / asbestos) so it maybe related and it might be an idea to fit.
The coil, yes I did suspect this, I’ve done a resistance check and it’s ok - when cold though..
Air filter very clean, fuel is wetting the plug, I’ve had a volt meter on the spark plug lead and it’s getting voltage at the plug end - and I’ve tried few different plugs.
As you say, these things run for ever, or it has done up until now.
I think it might be a good idea and take the head off again and start from there.
TorqueVR said:
The truth is mate that it's knackered and you need a new one.
But to you, the other posters here and me it's a challenge. I've no idea what the problem is but don't give up. Sorry I'm no help but I am of the same mindset.
I bought it for my late father as a birthday present in 1992, it’s become a bit of a family joke that I’ve kept it going. Back in 2007 the engine was very tired, I won a complete mower on eBay for a tenner. It was down in Matlock which was a fair distance from me. I hired a van for the day, I wasn’t sure what to do with my late Boxer dog, so he came on the journey with me - a grand day out for all.But to you, the other posters here and me it's a challenge. I've no idea what the problem is but don't give up. Sorry I'm no help but I am of the same mindset.
Yeah, I am quite attached to it. I’m thinking of buying a battery powered one as a temporary measure. The Villiers will run again - I refuse to let it beat me.
After all, I got my Elise going again, and I had that down as far more complex than this.
Jim H said:
The coil, yes I did suspect this, I ve done a resistance check and it s ok - when cold though..
It will test fine cold. It may even produce a weakish spark. However, that that spark will likely be even weaker or non existent in compression. Once the windings get hot, shorts will become apparent and any spark you did have will fail. In all honesty, I’d leave everything else alone and put a new coil on it. Follow the golden principle; change only one thing at a time. I suspect you’ll be fine with a new coil (plug and HT lead if not already done). It’ll then be fine for another 20 years of maintenance free mowing
FlyVintage said:
Jim H said:
The coil, yes I did suspect this, I ve done a resistance check and it s ok - when cold though..
It will test fine cold. It may even produce a weakish spark. However, that that spark will likely be even weaker or non existent in compression. Once the windings get hot, shorts will become apparent and any spark you did have will fail. In all honesty, I d leave everything else alone and put a new coil on it. Follow the golden principle; change only one thing at a time. I suspect you ll be fine with a new coil (plug and HT lead if not already done). It ll then be fine for another 20 years of maintenance free mowing
I will report back.
Happier times!
https://m.youtube.com/shorts/ipI_8dZV_AE?ra=m
Jim H said:
FlyVintage said:
Jim H said:
The coil, yes I did suspect this, I ve done a resistance check and it s ok - when cold though..
It will test fine cold. It may even produce a weakish spark. However, that that spark will likely be even weaker or non existent in compression. Once the windings get hot, shorts will become apparent and any spark you did have will fail. In all honesty, I d leave everything else alone and put a new coil on it. Follow the golden principle; change only one thing at a time. I suspect you ll be fine with a new coil (plug and HT lead if not already done). It ll then be fine for another 20 years of maintenance free mowing
I will report back.
Happier times!
https://m.youtube.com/shorts/ipI_8dZV_AE?ra=m
I’m not completely bonkers - honest!
I just think it’s lovely to have something from the sixties, and it was working perfectly up until a few weeks ago. When everything is just thrown away these days (goods similar to this). I find it astonishing that something so old has lasted so long.
Ok, it’s a bit of ‘Triggers Broom’ the engine is from the mower I collected from Matlock. But still on same chassis and gear train etc.
And obviously I’ve kept it maintained. A few years ago I picked up this old manual off eBay.
Could you imagine something like this being supplied with a mower now?
I’ve requested a quote from the Villiers parts that Fly mentioned above.
Thanks for your help Fly, much appreciated.
The manual has kept me going until now, sometimes you need the power of PistonHeads advice and help.
My late father was a big cricketer, he kept the lawns at my house like Cricket wickets, I have maintained the tradition.
I just think it’s lovely to have something from the sixties, and it was working perfectly up until a few weeks ago. When everything is just thrown away these days (goods similar to this). I find it astonishing that something so old has lasted so long.
Ok, it’s a bit of ‘Triggers Broom’ the engine is from the mower I collected from Matlock. But still on same chassis and gear train etc.
And obviously I’ve kept it maintained. A few years ago I picked up this old manual off eBay.
Could you imagine something like this being supplied with a mower now?
I’ve requested a quote from the Villiers parts that Fly mentioned above.
Thanks for your help Fly, much appreciated.
The manual has kept me going until now, sometimes you need the power of PistonHeads advice and help.
My late father was a big cricketer, he kept the lawns at my house like Cricket wickets, I have maintained the tradition.
Jim H said:
Hi Fly, and thank you.
It did run briefly after the de coke, then I realised that the thread for the spark plug was poor, so I had a spare cylinder head and fitted that...
It s not run at all since I swapped heads, I do have a new gasket (non copper / asbestos) so it maybe related and it might be an idea to fit...
If it ran with the original head then that has to be the place to start, then the new coil when it comes.It did run briefly after the de coke, then I realised that the thread for the spark plug was poor, so I had a spare cylinder head and fitted that...
It s not run at all since I swapped heads, I do have a new gasket (non copper / asbestos) so it maybe related and it might be an idea to fit...
Always worth keeping these old mowers going, they are build like tanks compared to modern cylinder mowers. I bitterly regret giving my Dad's Qualcast Commodore away when clearing the house, it purred like a kitten. The modern one I bought (off ebay for £150 unused) is utter junk in comparison.
PushedDover said:
left field and what I have found of late - the petrol now is so sensitive to going off when stored.
Additives needed to the jerry can when at the pump if not getting through vast quantities.
My more modern mower was struggling when hot, and we put it down to gumming up from s
t fuel.
Some engines are more sensitive than others.Additives needed to the jerry can when at the pump if not getting through vast quantities.
My more modern mower was struggling when hot, and we put it down to gumming up from s
t fuel.I buy fuel I expect to use within a few months, or syphon a bit from my bike.
Also keep it in sealed plastic cans.
If I'm not going to use things like my strimmer for a few weeks, I empty the fuel back into a can and seal it.
I get called on to get outboards, mowers and stuff running, and fresh fuel is now high up my list of things to try, since I saw it work after a mate had bought a new plug, stripped and cleaned the carb etc etc to no avail.
Ignition systems on magneto engines can be a sod, the spark can be quite small when trying to start the engine or pulling it over, You don't get a respectable spark like with electronic or battery and coil, even if the system is perfect.
Also with an old engine, several things may be a bit off, sort some of them it may run after a fashion.
Perhaps it had better compression when the head was full of coke?
I have an old points based side valve Billy Goat, which was unreliable. Converted it to electronic ignition was a game-changer. Less than 10 minutes using one of these
https://ebay.io/m/NmOaE0
https://ebay.io/m/NmOaE0
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