OutdoorKing Repair Forum Forums Restoring, Customising and Modifying Engines Magneto Repairs on Villiers 412 required ?

Hi all ODK members.

I require the services of someone that can repair the pictured magneto assembly from my Villiers 412 engine. It is not giving out enough spark to run the engine.

Any ideas would be greatly appreciated.

Cheers,
BB.

So it is sparking? Can you take the points cover off? Youve done all the obvious servicing? points cleaned,are they serviceable? coil faces clean,broken wires? No cracks in the ht lead or is the plug connector corroded? Condenser tested? whats the flywheel like? Did you check the timing,when the mag was on?

just looking at the pics in question it seems the whole thing is in need of a severe clean up. it looks like a heavy black build up of some sort on your coil mounting plates and i zoomed as best i could to see your points and they look heavily carbonized.all would be detrimental to achieving the best spark possible.electricity needs an inductive path to flow and i dont think that goop would be helping it achieve that outcome.as you say it does have some spark so this can only improve it.hope this helps

Hi Blue and Gizmo,

Thanks for your tips, I shall have a bit of a better look at it in the morning and the points issue certainly makes a lot of sense. One thing to consider is that this "Supercut" SB mower is an all original unit that has probably never been played with in this area of the motor but has been sitting idle for well over 5 years outdoors under a carport in the Adelaide Hills.

I've just gone out to the ute and brought it inside (wife already gone to bed, that's a good start) The black on the plates is in fact black paint that's flaking off, the point contact faces could certainly do with a clean as they are white all over the flats. I had already resoldered the plug connector back onto wire as that had come adrift.

As far as timing is concerned I notice that this one differs somewhat from the C12A that I also have. The flywheel has a wind on with centre nut set up and there is a timing mark on both the outer housing and also on the flywheel itself and I've noticed that the opening you guys can see on the magneto which allows you to see the points is a swinging window that is still in the same position as it was when I removed it, thus it was in the open position when it should (IMHO) be closed to stop any muck getting into that area. So from that maybe someone many years ago had the flywheel off and didn't put it on in the correct position. Now all I need to know is the actual procedure on how to set the timing up after I clean the points and then I might have a better idea of what I'm still up against or with some luck it might just work as it should.

Any help would again be appreciated as I can't find any sort of workshop manual on this motor, just an operators manual on eBay which has a parts listing in it. I've already previously received a parts listing from Rustic Spares. (thanks John)

Cheers,
BB.

my experience with some old villiers engines is that the timing marks can not always be relied upon to be correct.
i cannot see your magneto housing .its been removed to show the points etc. most of the villiers ive dealt with have the camming device (Cam)built into the housing and the timing and marks corresponds to it.However in saying that, you would be wiser to remove the spark plug and poke a screwdriver down the whole and rotate the engine up to top dead centre.because the villiers have no woodruff key or keyway (some do )you need to set the timing by manually adjusting then tightening locknut.
to get it close to correct,, rotate the engine backwards till the piston lowers 3mm from tdc.this is the position that the points should just start to open.
i have a link somewhere of a really good explanation for villiers engines . will try to find it and add it to this post
no luck finding that info must have been removed?
i did find the correct position for the piston in imperial, 3/16th of an inch below tdc.
i dont know if you engine is a 2 or 4 stroke .if its 4 stroke then this needs to be on the compression stroke ,not exhaust stroke.

extra note: some 4 stroke villiers are anticlockwise rotation

Hi Gizmo,

Firstly thanks for your willingness to help out here as I must admit Villiers is a whole new ball game to me.

My engine is a 4 stroke, side valve engine.

Now today I've managed to open up the ignition cover as the screw that holds it plus the points into position was one of the most unbelievably tight screws I've ever had to undo without damaging the slot in the head which had been previously burred a bit.
Now from what I've worked out the flywheel is undone and that in itself pushes the flywheel off the crankshaft. That nut that you undo must somehow come out of the flywheels so as to be able to remove the thin ally plate that covers the two openings in the flywheel casting which gives you access to the magneto assembly so you can make the required adjustments with the flywheel on as the points can't be adjusted without the flywheel as it has the cam lobe on it that the points are driven off. Hope I'm making sense here.

Anyway here are some photos to show my dilemma about removing the centre nut that will allow access to the magneto in its working position and get the timing set up correct.


The Flywheel with the centre nut and the cover plate (green)

Showing the access thru the Flywheel that I can't remove.

The timing mark on the Flywheel, there is also the corresponding mark on the top of the backing plate (not pictured)

Im not familiar with this engine,but the midget series has an alloy cover also and slides ove the nut.

The nut on the brass flywheel of the midget is riveted on and cannot be removed. But once the alloy cover is slid off over the nut the points are easily accesable. This im assuming is what your looking to do. With the flywheel off see if you can gently tap the alloy cover through the flywheel cutouts and see if it moves...just gently so as not to damage anything. If the nut is over the alloy cover then dont try this,but i suspect the washer and alloy cover are a tight/interference fit over the nut (to keep it sealed from dirt and moisture) and should be able to be removed with slight force,as this is how the midgets are done and it looks very simlar to them. As I said,if the washer covering the alloy cover is fit over the nut then it can be removed,but if the nut is definately under that washer,then,im unsure...I suggest you clean around the washer with a wire brush and give it a hit with wd 40 or similar and see exactly how its placed in relation to the nut. Im almost certain both washer and cover should slide up over the nut with a gentle prise and clean/soak with WD. The fact the flywheel puller points are directly under the cover also indicates it should come of this way,and possibly the screws if used to hold the alloy plate on are also under that washer.. See how you go,but this is how I do my midgets,and also pretty much the same for timing as gizmo has explained.,Just get that top of so it can be timed then your on the home run!....

yes that plate needs to come off .somehow
if however you think you may damage it by trying to get it off .i have another suggestion. the timing mark if correct should correspond to the almost highest spot on the cammed lobe.its a bugger of a suggestion i have but it would work.
using vernier calipers measure the thickness of the thickest part of the cam. get a spacer of the same thickness and put it between the points lifter and the shaft. this will in theory give you the same full open gap for the points setting as the cam would have.
now if your timing mark is the correct position you can put the housing back on and line up the timing mark to tdc.

Hi Blue,

I must say that it is a rather strange one. The ally cover is rather free and can be easily rotated around the nut and there are holes through it that correspond with the 3 fine threaded holes in the housing. (flywheel) It's as if there should be 3 long bolts that should be wound into the holes and through the ally cover and pushing against the washer to pop the nut assembly out of the housing, would that maybe be the case ?

Cheers,
BB

i edited my post above

I would generally say those holes were to press the flywheel of the shaft,but in this case you might be correct. If the washer and alloy cover are a press fit as I stated then 3 bolts fitted and turend evenly should push it off,same way as it would in reverse to take a normal flywheel off....Yes give it a go very carefully, As I can see this makes sense. Next time you get another villiers,just run subtle external marks on the flywheel side and the coil plate to make it easier,especially since you had some spark to start with indicates its roughly timed correctly and just needed points servicing and cleanup. Just a hint...But when all is said and done,timing of piston position as Gizmo described is as accurate as you can get. so when youve checked the piston is at the correct place and the timing marks are correct,then it cant be wrong...Good luck,hope you get it running soon...love the old Villiers engines....:)

Thank you so much Gizmo as this is the exact beast I have !!
The flywheel diagram shows a circlip in front of the captive nut which I'm going to have a closer look today when the sun comes back up. There is some very valuable info in these pictures which I haven't been able to find anywhere, but it still seems strange that there is no mention of how to gain access to the points with the flywheel attached which is obviously the only way one can set the gap correctly, anyway I'm going to have to locate 3 inch and a half or longer threaded bolts which use the same thread as the two small bolts that hold the cowling to the backing plate as that's the thread in those small holes in the flywheel, BTW any idea as to what thread they would be ? as I've found most of the bolts on the Villiers are BS sizing which I assume is the same as British Standard Whitworth ?

and again thank you so much as this info is helping immensely

Cheers,
BB

Awesome info Gizmo. Should All be whitworth/NC....Id say its 1/4 w 20...which is just a std 1/4 nc 20 thread/bolt,youve probably have plenty lying around. Hard to tell from a Diagram as they look so small....Try a std 1/4 unc bolt first and see. The other alternative would be 3/16w 24 if they are smaller. Let me know if the threads are finer and ill get you the those sizes too:)

The diagram doesnt apear to show the flywheel cover plate or washer that sits ontop of the alloy cover. So im assuming the circlip is still Underneath it...Gotta get that plate off

Hi Blue,

Yes that issue with the cover plate is a real bugger as I've had a look at it all again this morning and I can't find a circlip that's accessible at all. The only place I think it could be is internally just like a drive shaft on a front wheel drive car which has a ring inside a groove that compresses when you place excessive lateral force on it thus releasing the nut assembly out of its housing.

How does that technology sound for a Villiers ?

Cheers,
BB

Too much technology lols.......Naaa of course it possible,but ive never seen this system on a flywheel before,only on the thousands of crappy cars Ive had to work on every year....lols.....From what i can see, the circlip issue isnt really important. Seemingly the circlip doesnt hold the plate on,it holds the nut/cam in the flywheel assy,which is not going to help with timing,infact I doubt it even needs to come out. Your really just looking to remove the cover plate so you can do your timing accurately yes?. The diagram Gizmo supplied does not show the cover plate and washer,which to me means the circlip is underneath the Cover,NOT holding it on. Have you tried to use the screws to push the Alloy housing and washer up over the nut shaft as yet? what was the result? Sorry its frustrating,as i know i can work it out if i had it in my hands. Give both ways a try and see what how it goes.

Hi Blue,
You bet it's frustrating. I'm going to try the three long thin bolts tomorrow and see if I can see the circlip under the ally plate. I must admit that I think you are correct in saying that the internal driveshaft type arrangement wouldn't be the go. I must admit I too have done plenty of motor rebuilding in cars but this magneto stuff is something I haven't done much on at all except for Briggs engines and their points.

I'll let you know the result asap.

Once again thanks for your moral support.

Cheers,
BB

Hi BB,

In having a look at your prob from what has been posted in your pics and Gizmo's information (which is excellent), I have come to this conclusion:

(1) From your pic with the green cover and rusty washer and flywheel nut with no circlip groove visible, I surmise that (as Blue said in his reply) the washer is an interference fit with the nut and if you soak the area in WD or equivalent, place a small thin drift in the flywheel puller holes from the inside of the flywheel...tap gently in all three holes, the cover and washer will release.
My reasoning comes from the left hand illustration in Fig 1 (Page 6) of Gizmos post, where you can see the flywheel in-situ with the flywheel nut still fitted

I believe also that the circlip only needs to be removed if you are replacing the flywheel nut for whatever reason.
Hoping this helps,

Hi DJ,

I'll give that a go later on today and report back what I find, nothing ventured, nothing gained I guess.

Cheers,
BB