Villiers 25HS powered generator

As I hadn't worked the gen set since last year I thought I'd tackle a bit more today!
Basically got the engine together but have a couple of questions, there's no guidance in the manual with regard to setting/zeroing the governor, so with the engine at rest and the arm against the engines centrifugal weights I adjusted the linkage to give full throttle on the basis that as engine speed comes up it will get throttled back to what the big Spring adjuster is set to?
I intend to run the engine without governor linked in until I am happy with it, somehow I don't like the engine going straight to governed speed (3000 rpm) from cold.
I'd like to introduce a disconnect mechanism to avoid this.
Previous engines I've worked on I have used a 10/40 engine oil, usually Comma, the data I have on this engine suggests Castrol XL 30 grade - did I ought to get some?


Also I initially fitted the fuel tank with the cut out radius in the strap to line up with the filler as it seemed like that was what it's for but doing this tips the filler off level with the petrol tap also more difficult to get the pipe on properly?
I've moved the tank so filler and fuel tap are level but as you can see it's now half a hole out from the strap cut out!
Is this normal?

Alan

This is the governor setting instructions in the manual, once you get past the warnings not to touch it




Plus a couple of tank mounting pics

That is looking superb!

I've not come across that cut out in the tank strap before, looking at my ex AM MK25's they have 2 flat tank brackets, not a 'kinked' one like yours, but my MK25HS does?

Thanks robotstar5, I like the way it says about no adjustment is possible, then in the next paragraph it describes how to adjust it! Seems like I was on the right course, I suppose the final governed speed is set with the long threaded screw on the spring.
I see your tank filler is down the opposite end of the fuel tank?

Mattblack, I guess things might have gone on over the years with a bit of mix and match, there's no saying mine is original as it has been rebored/ground in the past and had a few bits missing, I couldn't find anything of it's history, could this be found out from an engine number?

I measured the position of the carbs mixture screws before I removed them so have reassembled to the same position, but do you know of a 'starting position' for the settings? Like a manufacturers original setup.

Alan

Re. the governor setting, less tension on the spring will give a lower governed speed and vice versa.

I don't know the starting setting for the Zenith carb, assuming the engine was running before then your idea of putting them back to the same setting should work. I see Woodsman's manual gives the running settings.

Got there before me Stuart!
I've had similar issues with the cut out strap. IIRC it should sit between the cap and the raised seam. Also, check exploded diagram for cranked brackets and alignment of tank.

Zenith settings on page 14.
I usually close the idle screw fully but gently and then back it off two and a half / three turns

Thanks, looking at the diagram it looks like my tank is the opposite way round! (that's how it was when I got it) although even with the straps moved or even turned round it wouldn't help to line up with the filler!
Might be the best I will get is to turn the strap upside down so the cut out is out of sight?
Modified the governor throttle linkage today so that by removing an 'R' clip it can be disconnected, will check jet settings and could be going for a fire up!

Alan

Finished my disconnectable throttle modification today, final check over, filled with oil and some fuel.
Bolted it onto its base and got pulling on the rope.
Few bangs and pops till I gave it a bit more tickover on the throttle stop - and it was running!
Mechanically it sounded good so I had a twiddle with the carb screws and only managed to make it run worse! Ran it till the sump was warmed up and then noticed the air filter rattling around as the carb manifold screws had loosened, a lot, which obviously didn't help my running trials!
Hope to get it running better than the video shows but will get the generator up and running and under load before I carry out any further trials.


https://youtu.be/QeJMWSEc7s0

Alan

Yay!

Nothing like that first start up!

Raining all day today so had to assist in Christmas decoration removal - but then I got out in the workshop!
Plan was to assemble the generator rotor onto the engine then position the outer field assembly casing onto this, heating the bearing housing until it dropped in position then tighten up generator/engine bolts.
However as I positioned the generator case over the rotor it became apparent that the end ballrace would not be entering the housing very far. Measurement confirmed that the rotor laminations would also not be positioned centrally within the field coil laminations!
It was obviously running like this as I had taken a dimension of how deep the bearing was in the housing. What to do?
The rotor is keyed and grub screwed to the crankshaft with the grubscrews going into pilot holes so it's position was fixed axially.
I ended up adding two alternative 5/16 whitworth grub screw fixings in the rotor boss, one will require a pilot in the crank and the other will bear down on the long Woodruff type key.
So didn't actually assemble anything!

Alan

Things didn't quite go to plan today! (nothing new there!)
Repositioned the rotor so the laminations were in line with the stator which then pushed it into contact with the end casting! Not happy but no alternative but to assemble it as it came apart.
Photo shows how close one of the rotor bolts is to the end casting and also how much further the bearing needs to go into it's housing - probably another 3/8 of an inch!
Not particularly happy with the situation, obviously a lousy bit of design - (no CAD I guess!)
Good news is it rotates ok!
To be continued.

Alan

Alan it looks like part of the casting is broken / missing where the bearing should fit in on the part we can see
but may be wrong
Tony

Hi Alan stunning work
on your restoration
RichieR

Thanks RichieR!
Tony, there's nothing missing or broken and when I took it apart I measured the position of the generator bearing in it's housing - and it's gone together with the same dimension.
As you can see the slip rings are central about the brush mountings but in addition to the rotors laminations being out of position by about 5/32 the bearing end should have been longer to position the bearing properly in the housing! Never noticed it upon dismantling.
Quite a shoddy bit of design but it's obviously been like this since 1964 and running - so it can do a bit more!
Wired up the output panel this afternoon and made an additional bracket to secure the air filter directly to the cylinder head as when I had the engine running vibration shook the inlet manifold loose, so hopefully this will help.

Alan

Is it possible that at some time in it's life, the generator has been dismantled, repaired, dropped or wrongly fitted to something?
I'm thinking that if it is a plain shaft, could the armature have move along it, and then someone maybe pulled the shaft forward to make the slip rings align with the brush positions in the housing.

Good point and I wouldn't rule it out. I would suggest it's been like that for a long time as the bearing showed sort of corrosion marks where it wasn't in the housing.
Digressed today on a future project otherwise I might have had it running!

Alan

I was surfing Youtube recently and found a Villiers F15 generator restoration, don't know if the generator mounting bit is of any help?

Thanks, always interesting!

Alan

As my JAP project is paused while I sort the cowling out I had a bit of time with the gen set.
Took a few pulls to start, didn't seem to need choke.
While it was running I was prepared for an output and had various loads ready to apply, didn't need them though as there was no output, at all!
Generator has separate winding to generate a supply for the rotor, it is intact and buzzes out ok but as it's generating about 1 volt I believe this is well down on what it should be. (I don't have any info on the generator)
I'm thinking that to generate a supply to energise the rotor it needs some residual magnetism in the rotor laminations to initiate generation.
I think it's lost this and I now need to 'flash' the rotor like you do when changing a car dynamo's polarity?
Anyone done/carried out anything like this?

Alan

Sounds to me like you need to put a load on it and then excite it with a 12 volt battery there is some times a negative and a positive marked on the brush holders or a dab of red and blue paint with load on engine running just give it a flick

hope this helps Tony

Thanks Tony, what would be the effect of getting polarity incorrect as brush holders aren't marked in anyway although one is at chassis potential - could I assume that to be negative?

Alan

Had a resistance measurement of the rotor (88 ohms) and the windings that supply it (4.5 ohms) the actual generating windings measured (0.5 ohm) so appears all intact there.
I disconnected the brush supply and applied 12v with a power supply to the rotor for a short while, negative to chassis in an attempt to magnetise the laminations.
Fired up the engine and noted once again no output! At this point I briefly applied the 12v to the brushes and we had an output to light an Anglepoise lamp that I had plugged in.
I then applied the 12v for a longer period and with a bang and a cloud of smoke my power supply was no longer!
Bit disappointed but I believe putting a supply to the rotor and leaving the windings connected enabled it to generate a supply for the rotor but also went back to my power supply.
There's 2 windings that supply the rotor joined in the centre with earthed diodes. I decided then to have a look at the diodes and found one open circuit, great I thought this could be the problem!
Photo of diode showing how it's connection has fractured off the body. I didn't have an equivalent diode so took a chance and soldered it back on, it soldered well and appears that the heating didn't destroy it.
So it's all back together ready for another power up!

Alan

Bit of a gap since the last post! Due basically my JAP pushing it's way in!
In the last post I had found an open circuit diode in the rotor supply circuit, this was soldered back together and today I started it with a digital meter connected to the output and a load ready to be applied.
Took a couple of pulls with choke on then with choke off it started. I have the governor disabled at present as I didn't want it to runaway.
Switched on the supply for the rotor and was rewarded with about 170 volts! Yippee, all that was defective was the diode but as it was encased in heat shrink it was physically held together but not enough for a circuit so it 'looked' ok.
Wound up the idle screw while it was supplying a 1kw heater, sounded good and after a while the generator case had the chill off it.
Now need to connect the governor linkage and set it so it provides 50Hz output and hopefully this will give 230/240v

https://www.youtube.com/shorts/5cOiZMEhR7g?feature=share

Alan

Alan well done, all you efforts have been well and truly repaid. Not only a good looking engine but one that sounds as good as it looks, as well!

Neil.

Great result, another one saved!