Villiers MK20 HS

What I really appreciate about forums like this is the fact that others go through the pain of the issue (in this case TPI and identity of the thread..) and lucky oiks like me save half a lifetime by just loggin gon and reading the thread - well I shall raise a glass to you next time I'm in the pub - which wont be long...

Honestly - top tips from here have sorted so many issues - great stuff and thanks to Woodsman and Nutgone for going through the pain

... and enjoy HK... Jumbo Floating Restaurant perhaps???

Best

Hamish

Hi Hamish,

We will be staying in Aberdeen part of the time but don't think we'll be going to Jumbo - it's hellishly expensive. Also, the last time we were there an old sampan owner and his wife cajoled us into a trip round the harbour for a fiver. Money well spent but we saw the back of Jumbo and it's just like the back of every Chinese restaurant - but on a much grander scale!!!

Just came across this thread after picking up an old MK20 today. Looks like it's been sat outside for quite a while as both the tank and the cowling have rotted through at the bottom. The engine appeared to be seized but started to turn after I tried to undo the flywheel nut with a fairly long lever on the socket, turns out that the flywheel was stuck on the housing. Tomorrow I'll try to get the flywheel off and see what's behind there. I have the head off, all looks to be fine under there, luckily both valves were more or less closed, only the exhaust valve is sticking a bit.
Main casualty so far is the carb, the 90 degree manifold has been snapped just where it joins the flange at the barrel end, also the fuel pipe fitting on the banjo has snapped, so it'll need a new banjo, or, depending on what else is wrong with the carb, maybe the whole thing is a basket case.
If I can get the flywheel off, and coax a spark out of it, I may try to get some other bits for it.

Does anyone know where I can lay my hands on the manifold & banjo?

Always my first port of call is L&S Enginners- very helpful and friendly. If you can't see what you want on the web site give them a bell. They sorted me with a pinion for a reduction box.

http://www.lsengineers.co.uk/villiers-mk10-12-15-25-banjo-bolt.html

I think I have a MK10 manifold which may well fit - will check over the weekend. Don't forget that the flywheel nut is a "hammer tight" so a good clout with said tool should shift it.

http://www.stationaryengineforum.net/t7502-villiers-mk20-4-stroke-how-do-i-get-the-pull-start-pulley-and-rotor-off

Woodsman, I think you're right about the MK10 possibly fitting, thanks for the offer to look but I found a few more problems today that I think will mean that this engine will need to become a parts donor.

After a lot of effort, I got the flywheel off. The nut came undone easily enough but the second stage to get it off from the taper was a real chore and took a lot of time. Underneath all looked in order and reasonably clean but the coil shows an open circuit on the HT side.
I took the float bowl off the carb and apart from a handful of rust inside, the float itself has a massive gap so would need to be replaced and that's in addition to all of the alloy corrosion so the carb is no good. Maybe the main jet can be salvaged but that's about all.

So, on the face of it I have an engine that will need a new coil & carb at a minimum to make it go, plus a new tank and repairs to the cowling. On the plus side, the head looks ok with slightly worn plug threads, the barrel, bottom end & flywheel etc look good and so far as I can tell the reduction drive is ok.

I'm not sure what the policy here is on advertising, so I won't mention any money just in case it's not allowed. Hopefully I'm not going too far by asking anyone that's interested to PM me?

You will find another carburetter on ebay fairly easily. As for coil, always the bane of Villiers restorations, have a look at Matt's excellent 'how to'

http://www.stationaryengineforum.net/t6890-coil-ignition-without-a-battery?highlight=ignition

Woodsman, many thanks for the link to that excellent idea. I'll leave the offers open to anyone for the engine as parts and see how things go. It's also listed on the 'for sale' part of the forum.

A quick update,

When I got the coil off, I found that the wire used for the stop switch which runs behind the coil had some of the insulation worn away by rubbing against the backplate, this got me thinking this may be the reason the engine was abandoned in the first place, so after cleaning the points and removing that wire,I put it all back together, spun it by hand and there's a spark! Although the HT side shows an open circuit, it may just be a small break in that winding, time will tell.
I did see a carb on ebay over the weekend, but it went for too high a price so I decided to see what can be done with the one I have. Yesterday I persuaded the float halves to become one with some bad soldering and managed to get the carb jets to the point where I can see some light through. Still need to tackle the broken manifold pipe & banjo though.
I have the valves out, there are no shims under the buckets, but the buckets look to be machined on the valve side to different depths. Seats look good enough for a quick re-lapping which I'll do in the next couple of days.

Hi, checked our spares box the manifold is off a MK10/12. Same hole pitch on the barrel end as the MK20/25 but a knuckle bend rather then a swept bend so I doubt things will line up. However, if you try L&S I'm sure they will be able to help.

http://www.lsengineers.co.uk/villiers-mk25-inlet-manifold.html

http://www.lsengineers.co.uk/villiers-mk25-silencer.html

Thanks for the links to LS. The silencer is a possibility, but the manifold looks like it will hold the carb up at the same height as the MK10 manifold, although maybe farther away from the barrel.

Hi cancunia (real name?)

Ah, I think I have it  
Our MK20 is fitted with a Villiers carburetter and uses Inlet Pipe Part number DM195 (the swept one)
Our MK20HS is fitted with a Zenith carb and uses Inlet pipe Part number DM.1381    (the short one) as per L&S web site


For comparison with a MK10/12 manifold :

The offset from the cylinder looks about the same...


but the height looks way different...

Hi Woodsman,

Aha, thanks for the pictures, that explains a lot.

Hi,

What carb have you got?
You can have MK10 inlet for cost of postage. It's a bronze casting and has been repaired previously but a bit of work with a file and some VHT paint should do the trick. PM me if interested.

Many thanks Woodsman, PM is on the way. My carb is the same as the one in your lower picture, so it should fit with a little adjustment on the governor.

It works, started first pull! Well it fired a few times then stopped, more on that in a moment or two.

Firstly many thanks to Woodsman for the manifold, without that and some words of encouragement I would probably have it on ebay by now.

So, I lapped the valves, cleaned & gapped the points and put it back together. The carb looked like a basket case with a burst float and lots of corrosion inside, but I managed to get the float back in one piece with some persuasion & dodgy soldering. The main jet came out ok and the passageways cleaned up enough to let fuel & air through. I used a biro spring on the tickler to replace the totally rusted one.

I timed the engine using a meter on the points, you can just see the change in resistance when the points open. As usual, there's an arrow stamped on the flywheel, this lines up with a mark right on top of the flywheel backplate casting when the piston is at TDC. I double checked this when i had the timing as close as I could make it so it's a handy reference and good enough to get the engine running.

The engine fires without a problem and shows quite a good spark even when turning by hand, so I'm guessing that the grounded cutoff wire behind the coil was what caused the engine to be dumped. The main problem now is that I can only get it to run with one finger halfway over the air intake, probably due to the lack of air filter which had completely rusted away. I may be able to compensate for the lack of air filter by lowering the main jet a bit. I'll take a look next week some time.

I'll start a new thread with some pictures soon.

Hi Cancunia, the timing marks are for timing the ignition not for TDC of the piston, the Piston should be 3/16 of an inch below the top of the bore and marks aligned, this is best achieved and more accurate when the head is off, although its running its probably not timed correct as they do run ok without an air filter as they are quick to warm up, once running the mixture screw on bottom of carb can be adjusted to get it to run better. Regards Richard

Hi Richard,

I initially set the timing at 3/16" BTDC using my meter. With this set, the arrow stamped on the flywheel is also a little before the top. After setting the timing (points opening at 3/16 BTDC), the arrow aligns with the mark at the top of the casting when the piston is at TDC. I was told that the arrow is stamped at the factory once the timing is set so that it can be done quickly during servicing. In any case, I will check again if I can't get it to run any better once I've played with the main jet.

I got this some time ago from George Shead at Villiers Parts (slightly edited here):

1, set piston at TDC, (On 4 strokes both valves closed comp stroke)
2, fit flywheel loosely. (MAKE SURE THE TAPER ON CRANKSHAFT IS CLEAN!!, ALSO NO OIL ETC INSIDE FLYWHEEL NUT/CAM PART OR IT WONT GRIP,) Be carefull not to bend or break the tin lube arm on outside of points box when fitting flywheel (later type), turn until arrow on this lines up with arrow & or line showing on outer edge of backplate.

Engine back on the bench. Despite the previous owner stating that the jigsaw had all the pieces I found a number of parts missing. However with a few purchases from fleabay and generous help from members it's slowly coming together.

But here's a question. The sump oil fillers are fitted with extensions. The increased height means that with the governor arm in place one of them is useless. Any thoughts?

Hi Paul,

Sorry for asking, but are you sure the oilsump is mounted correct?
At my Mk15 the governor arm is located at the opposite site of the filler plug (with extension)

See pictures in Dutch Villiers Mk15

Hope this will help.

Best regards,

Steef

Hi Steef,
Oil filler plugs on both ends of the sump.

Hi Paul,

Didn't realize that there are 2 oil fill plugs.
Suggest to position the one with extension to the opposite site of the governor arm.
(If possible of course)
What is the reason that there are 2 filling plugs?
Is this common at Mk20 engines?

Best regards,

Steef

Hi Steef,

My MK25, 3 MK20s and a 'V Engine' all have two filler plugs. Don't have the option to reposition since the fan cowl is attached to two studs in the sump. Do not really understand why you would want to raise the dipstick as the manual states same oil capacity for both normal and HS versions

Hi Paul,

Sorry for the confusion.
Not my intention to raise the dipstick.
Thought that repositioning the oilsump by turning 180 degrees should solve the issue with the conflicting governor arm.
Never realized that the engine cowl is attached to the oilsump.
Still interesting to know why Villiers has created 2 fill openings on the oilsump.

Is it possible to mount a governor arm like on a Mk25? (See picture)


Or see a MK 20 on E-bay
http://www.ebay.co.uk/itm/Villiers-MK20-Stationary-Engine-/172256888045


Best regards,

Steef

Hi Steef,

MK20 HS uses Zenith 24-T2 carburetter  so governor arm links to throttle on right side of carb. Not going to worry about it. Next owner can scratch his head.