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Collection, Preservation and Display of Old Lawn Mowers

Villiers v1c

Having removed the barrel i see that there is a large carbon buildup in the crankcase which i would like to remove but it raises 2 questions,i have read the article on timing the engine and as i understand it the arrow on the flywheel has to align with a corresponding one on the crankshaft that is visible once it is removed?also i would like to remove the backplate but no mention is made of marks so is this drilled to accept the locating screw or should i mark it relevant to the crankcase?and finally does the crankcase use a gasket between the 2 halves as i cannot see a trace of one.

I have read that carb cleaner will dissolve the carbon deposits which are soft and figured that to do the best job would be to split the crankcase,anyone else been down this road before?


wristpin Sat, 24/06/2017

Not sure what a V1C is and hoped that someone else would jump in with some definitive answers. Personally I would avoid splitting the crankcase for the fun of it and suggest filling it with your chosen solvent and leaving it to soak for a day or two before flushing it out with petrol - usual precautions.  If you do split it I dont think that you will find a gasket, maybe just some traces of a thin sealant such as Wellseal (lovely smell) or these days Hylomar . I'd avoid Red Hermatite etc.

I believe that most Villiers two stroke cranks have a notch in the threaded mag end and maybe the drive end corresponding to the big end crank pin ie top dead centre so if the arrow on your flywheel corresponds to TDC, when fitting the flywheel you "eye" the arrow up with the notch. BUT I think that I've read somewhere that the arrow may be stamped in to give the required Before Top Dead Centre breaker cam position when aligned with TDC. A manual will help but a bit of trial and error will reveal the validity of this  - or otherwise.

Here's the notch

While on the subject ot TDC , as silly as it sounds, finding an accurate TDC can be a bit hit and miss. A probe poked through the plug hole is fine until one gets to that point where there are a few degrees of "squidge" (technical term) where moving the crank does not seem to give a positive position. Even using a Dial Test Indicator produces a similar area of doubt. However there is a simple method - the positive stop method . This needs a 360 degree timing disk that may be downloaded from the net and glued to a piece of card or plastic and a Stop - some thing screwed into the plug hole that protrudes into the bore enough to hit the piston when it's an inch or so from TDC, the actual measurement is not important. You can buy a suitable stop from a motor bike shop that deals in stuff for old two-strokes or make one . I've made a couple , 14 and 18mm plug size, using old plug bodies. Mine are adjustable because they double as timing gauges  but  that is not necessary to find TDC


Insert the stop so that the piston hits it at about an inch before TDC. Set the timing disc on the crank with a fixed pointer and align to zero. Rotate the crank away from the stop, down past bottom dead centre and back up until it hits the stop and read off the number of degrees traveled - say 300. This leaves the distance between the two stop points at 60 degrees. Without disturbing the crank, disc or pointer, remove the stop and advance the crank 30 degrees  - there you have an exact TDC.

Probably all a bit OTT for a lawnmower but for an accurate starting point for setting the BTDC contact breaker opening point, it is useful; however for setting cam or injector pump timing on something a bit more technical it is essential. Some engine manufacturers helpfully give the BTDC figure in degrees rather than linear piston movement and with the timing disc left in place it makes it easy. If only linear movement is specified it's a bit more of a fiddle  but that' s where my adjustable stops come in! 

EDIT . I've just had a flick through some Villiers manuals and the one for a Mark 26c has this to say about timing marks.

"Magneto Timing.

The magneto is timed to give a spark when the piston is 5/32" BTDC, with the points commencing to open. When building the engine the timing is set as above, the flywheel tightened on the shaft and rotated until the piston is at the top of its stroke (TDC). Two timing marks are then punched directly opposite one another, one on the boss provided on on (the) back of the armature plate, the other on the flywheel rim, as close as possible to the armature plate."

So in this case the timing marks are for when the points should open and not for Top Dead Centre.

NOTE - "in this case" - does not mean in every case!





jarrett Sun, 25/06/2017


Thanks for that will have to get a gallon of carb cleaner then,think what i may do to be safe is centre punch the flywheel relative to backplate and also mark the backplate relative to the crankcase and btw the engine is in a Atco Standard

jarrett Tue, 27/06/2017

Having got the flywheel and backplate off i have found that the coil secondary is o/c so will need another,having looked on the web i see Villiersparts do one that i think is correct although a bit pricey but better than some of the other stuff i have seen,has anyone dealt with this company and have any feedback as to quality and service etc although i note they state that they have a guaranteed 50 years working life so must be confident of what they sell.
Have also worked out the timing as it looks as though you line the arrow on flywheel up with notch on crankshaft and then rotate the backplate?

wristpin Tue, 27/06/2017

Villiers Parts. Had several of their coils and a variety of other bits and never had any issues.
Timing, just follow the instructions on the Dropbox file that I posted , it was copied from the Atco manual of the day. Or, if you prefer find TDC and set the points to start to open at the BTDC figure given . Nothing like doing it from basics, just in case someone has messed with the arrows etc or some mixing but not matching of parts has gone on in the past.

jarrett Fri, 07/07/2017

Engine all back together and in the mower and timed near enough as damn it with new coil and lead fitted and 30 thou at the points,it will fire up but only for a few seconds and then dies so i tried depressing the tickler and it will run a couple of seconds longer but not convinced that it is a fuel problem as the tickler is fully up so the float chamber must be full,have cleaned out the carb twice to be sure but no difference but how much difference would it make not having the silencer fitted and just the pipe,i have read about back pressure etc but this is hardly a modern reed valve 2 stroke,also can anyone direct me to what plug i should be using as this could be at fault under compression and at the moment it has a ngk a6 fitted but as the lead has a ring terminal fitted rather than a cap i will need a plug where the screw can be undone.

If it is cooler tomorrow i will put the ht neon tester on and see if that dies with the engine not firing.

wristpin Fri, 07/07/2017

30 thou contact breaker gap seems a bit odd, on most Villiers of that era it is 12/15.  Any reason for not trying it with the full exhaust fitted?

jarrett Fri, 07/07/2017

I did think it a little on the large side regarding points but apart from a couple of pulls of wet n dry through them i left as found,this is the problem when it is 45 years since last playing with magneto ignition systems and now having to re-learn/recall it all and that's before we get to Whitworth threads,the reason i did not fit the silencer is that it is in primer at the moment but will refit and worry about cleaning it up afterwards,will advise what happens after readjusting points and fitting silencer.

wristpin Sat, 08/07/2017

When you have closed the points down to, say 14thou , you will need to check and reset the timing.



jarrett Sat, 08/07/2017

Closed the points to 16thou after finding the locknut was on cross threaded but after work with a needle file and a new but deeper nut all is good but it still fires up and runs for about 3/4 seconds and dies but i put the neon tester on and when it is dieing it still has a spark so it must be a fuel problem,the carb and pipe are clean as is the temporary fuel tank but i have noticed that it does need to drop of fuel straight in the cylinder before trying to start but only in the first attempt,putting the choke on for the first try does not make any difference,it still will not fire.

The carb is not the tightest of fits to the adapter pipe but if it is drawing air in it will be minimal and i would think not enough to lean it out enough to stop if starting,,strange fault somewhere but dammned if i can find it,

wristpin Sun, 09/07/2017

On an engine of that age it's possible that it's a  " cumulative" problem - a combination of low compression, ingress of air around worn main bearings etc, etc. So every small correction will help. 

jarrett Sun, 09/07/2017

It MAY have more than one fault but low compression is ruled out going by my wrist!the crank seals are good as no leaks of fuel/oil are visible and before the stripdown no traces of previous leaking,i think i may get another plug as i guess it could be breaking down and see what happens,any reccomendations.

hortimech Sun, 09/07/2017

The reference to your wrist, makes me wonder if the timing is wrong ? The only time I have heard anybody complain about wrist problems after trying to start an engine, is when the engine is 'kicking' back and it shouldn't do this if the timing is correct.


jarrett Mon, 10/07/2017

Just a touch of carpal tunnel with osteo arthritis which i guess is normal for someone who has made a living with their hands plus the wooden handle on the starting handle has long since disappeared! was going to take another look today but as it is still hot outside i will wait till it's cooler but will put the meter across the points instead if a fag paper and recheck. 

wristpin Mon, 10/07/2017

Play safe and check the points against the piston position rather than just  trusting the arrows, may save a bit of RSI . 

dieselvet Mon, 10/07/2017

Admit it is a different villiers engine, but my 2 stroke (from a kick start light) became a pig to start. Was totally fixed by some hematite around the carb/inlet joint. Fixed it instantly. Lack of vacuum to draw the fuel/air mix is a common problem on 2 stokes i've learnt.

Re the timing on this engine. The 2 arrows lined up when the engine was at TDC. 

dieselvet Mon, 10/07/2017

2 screen shots from miget engine manual. Different engine, but still villiers.

Sorry, they were in focus on the phone, but have been ruined in the upload.

wristpin Mon, 10/07/2017

Those arrows will only line up at TDC if the flywheel has not been disturbed since being re- timed so working from basics is the only safe way.

dieselvet Mon, 10/07/2017

Of course. The engine must be at TDC when the arrows are aligned. That is the critical part as far as I understand. The chamfer on the flywheel will then cause the points to open at the appropriate time. I guess the flywheel can slip on the tapered shaft if the nut is not tight enough or the shaft is oily. I have found presence of oil here is a bit undesirable. Don't wish to contradict your obviously superior knowledge on these matters wristpin!

hortimech Tue, 11/07/2017

The critical thing is that the points start opening at the right time, this might not be when the arrows line up. The backplate, flywheel or both could have been replaced at some point in its life. Atco used to offer a winter service on its machines, this involved a total strip down of the machine and then rebuilding like new. You could not guarantee that you would get back any or all of the machine you sent in, but you would get back a machine that looked like new. Atco didn't use the arrows to time the ignition, they timed the engines by setting the engine to the correct place before TDC and then ensured the points started opening at this point.


wristpin Tue, 11/07/2017

As Hortimech says, when the engine was originally built the ignition was timed from basics - ie the piston a linear distance before TDC. At that point the arrows were added to make life easier for less particular service work that might follow during the machines life. As I've touched on before even finding the true TDC is not as easy as it may at first appear and points etc wear so those arrows are not 100% reliable so going back to basics is not time wasted. 

On an engine that is approaching 100 years old there will be wear everywhere, and systematically  reducing  the effects of incremental wear to , bearings, carburettion, sealing and ignition etc can be the difference between failure and success  - take nothing as  "a must be or given" - check it and if possible reduce its effects by correct adjustment. 

As for Atco's winter service program I can just about remember their little open backed trucks running around packed tight with domestic lawn mowers in the autumn and spring but in those days mowing seemed to stop at the end of October and not start again until April!

Here is a link to the Atco winter service program as printed in the owners' manuals of the time  - and I think before the days of image manipulation.…

wristpin Tue, 11/07/2017

Of course. The engine must be at TDC when the arrows are aligned. That is the critical part as far as I understand. The chamfer on the flywheel will then cause the points to open at the appropriate time. I guess the flywheel can slip on the tapered shaft if the nut is not tight enough or the shaft is oily. I have found presence of oil here is a bit undesirable. Don't wish to contradict your obviously superior knowledge on these matters wristpin!

The golden rule with taper fits, whether the Morse taper on a pillar drill, lathe, mill or on an engine flywheel  is CLEAN and DRY.

Villiers expected their flywheel nuts to be ** tight and before the days of the universal use of torque wrenches, they used to supply what was colloquially  known as a "flogging spanner" ie. a wrench or socket with an extension specifically designed to be hit with a decent sized hammer. I was at a sale a couple of weeks ago and there, in a box of assorted rusty spanners was a Villiers flywheel nut one - and there are still new, old stock ones to be found on the internet.

This one is out of stock but they are still out there…

hortimech Tue, 11/07/2017

You must be further South than me, the grass stopped growing at the end of September and mowing used to start again at Easter, whether you had to sweep the snow off or not ;-)

I think Atco stopped their winter servicing in the early 80s, the company I worked for at the time used to send them all the Concord electric mowers, it was cheaper than us in the workshop and they looked like new when they came back.

wristpin Tue, 11/07/2017

Last snow here was over five years ago!

Concordes. That made me chuckle. When the cylinder grinding wheel on our BRL was nearing its bottom limit , it wouldn't reach down to  Concorde cylinders and we had to put spacers under the head and tail stocks so we built up a stock of ground cylinders for quick turnarounds .  One visit to a mobile home park to pick up their triple coincided with "bin day"  and yielded three Concordes - three extension leads and three stock cylinders !


jarrett Wed, 12/07/2017

After checking timing and putting another jet in from a spare carb it ran but was 4 stroking as it is a larger jet,the one fitted to the mower is a 40/22 and the spare i tried was a 35/20 so the timing cannot be that far out but yet again it died after a period of 8 seconds  or so which raises this question.

1 the clip that holds the float to the tickler/valve i have fitted with the detents against the float,is this correct.

2 at the moment it has a ngk a6 plug fitted which i am going to replace so is this the correct plug and can i use that number as a cross reference



wristpin Wed, 12/07/2017

Sounds as though you have the makings but as you surmise 4-stroking suggests a rich mixture, yet the short run period suggests a fuel issue. Does ir clear its throat and two stroke just before it dies?

The NGK A6 is an approximate equivalent to the old Champion 8 COM (or was it COM 8) ?  My own experience of the A6 in my old Dennis has not been entirely satisfactory and I've reverted to a couple of ancient Lodge and KLGs that are far less temperamental. Going to an autojumble on Sunday and will be on the look out for vintage 18mm plugs.


This may be of interest…

jarrett Thu, 13/07/2017

The 4 stroking was only with the larger jet and it 2 strokes for a shorter period of time with the jet that was fitted when i got the mower,i asked about the float clip because i was thinking the fuel level in the chamber may be to wrong especialy as the spare carb had a brass ring under it for some reason,also noticed that when the throttle lever is shut the slide is still about a quarter of it's distance up and not fully closed and that is with the adjuster wound right down.

Think i will get another plug and see what happens although as i said in another post it is still sparking when the engine dies but for all i know it could be inside the plug rather than the tip,did a comprssion test and it has 70psi when hand cranking.

jarrett Thu, 13/07/2017

Just spent a couple of hours on it and have found that with the larger jet it will run after turning the backplate but will try and 4 stroke at idle,i also tried turning the backplate with the smaller jet in and it makes little difference,it is a carb problem but i just cannot put my finger on it which is rather annoying as it is so basic an instrument.I will take the engine out now and put away as i now know it will run albeit sickly and can then prepare for the stripdown of the rest of the mower,i did not want to rebuild the mower and then find the engine was a clunker and incur more expense.

If anybody does know the correct jet size i would be pleased to hear from them and the way the clip fits on the tickler/valve rod would be a help as well but thanks to everyone for the advice and no doubt i will be asking more question shortly.