Can't get the flwheel off a Villiers Mark 15 :-(

Hi everyone,
I just acquired a Howard Bantam rotovator so removed the engine and have largely disassembled it. It's in great shape and I'd go no further than relapping the valves BUT the ignition lead is missing and I need to get to the coil.
None of the fasteners are seized and I was able to remove the rope start pulley from the flywheel with ease. I found an un-usual looking bolt which is a 1/4 Whitworth that has a "slim" central section. I screwed this into the female thread on the flywheel and assumed that as I tightened it, it would force the flywheel off the crankshaft as I can see the tip of the crank in the threaded recess. Now I'm not a strong man but I managed to bend the 1/4 Whitworth bolt as I tried to tighten it. I held the larger flywheel nut with a larger Whit spanner and I was very careful not to break any of the vanes on the flywheel. So I then applied some mild'ish heat and some WD40 but it just does not want to move. I even bought the Villiers Mark 15 engine manual but that contains nothing about flywheel removal. Can anyone offer any advice on this?
I'm not en engineer by background but I'm sure there's a trick I'm not aware of.
Thanks!
Neil

Hold the flywheel with a strap etc to stop it rotating, place a well fitting ring spanner on the large flywheel nut (it is a standard right hand thread) and hit the spanner hard with a hammer or mallet! It should be very tight, then when it goes loose keep undoing it and after a few turns it will go tight again. Use the spanner and mallet again to loosen it once more and then it will undo easily and pull the flywheel off at the same time.

Pete.

Thanks Pete - I think I have been going at it in the wrong way! Is it the case that the flywheel is held onto the crankshaft via a thread ? I thought it was an interference fit and that the smaller 1/4 Whitworth bolt would push the flywheel off the crank - your description implies the flywheel has to turn relative to the crank for it to come off - and this makes sense. From the manual it's not clear how the flywheel really attaches itself to the crank. Is the smaller odd shaped (1/4 Whit) bolt just to hold the rope-start pulley in place? Many thanks!
Neil

If the rope start pulley is still on, you haven't got to the flywheel nut. As above, the flywheel nut is free to turn in the flywheel and acts as it's own puller (the flywheel is on a taper) - quite a clever design really. Don't be tempted to wedge the flywheel with the vanes, you will break them. On the MK15 you can turn the engine to BDC and feed a length of cord down the spark plug hole, then gently turn the engine over until it locks up.

EDIT: I posted the above in a bit of a rush, having read your post properly I see you already have the pulley off.

If you only need to replace the HT lead there is no need to remove the flywheel, the lead screws in from the back of the mag backplate. Bear in mind that if you do remove it it is not keyed to the crank and you will need to reset the ignition timing.

Thanks! Yes I did get the rope start pulley off - it came off easily in fact. I forgot that I also want to replace the crank seals and I may as well replace the crank bearings so I will take it off. I can see the flywheel is easily broken so I'll be careful about how I hold it still. Many thanks to you both - these sites are a mine of great information...
Neil

Oh and thanks for the reminder about timing - I have clock gauges that will allow me to measure the piston travel (the manual does give the necessary details on this - 1/8th inch BTDC - haven't seen it given in distance before but it actually makes it easier to set with a clock...

If you change the crank bearings make sure you use quality replacements as there is a lot of 'not so good' ones!

Alan

What manual do you have? I have the genuine Villiers one covering the MK10, 12 and 15 in PDF form if you want a copy.

When you come to setting the timing there/s a arrow on the top of the alloy Mag back plate and a arrow on the rim of the flywheel to line up with piston about 1/4" before TDC

mattblack wrote:What manual do you have? I have the genuine Villiers one covering the MK10, 12 and 15 in PDF form if you want a copy.

Interesting. I have a manual covering MK10 and MK12 dated 1957 and two separate ones for the MK15 dated 1955 and 1956. What date is yours?

Some Lister/Petter and Villiers manuals are readily available on Winget's website


https://www.winget.co.uk/parts-service/heritage-machines/

Pete.

tony RA wrote:When you come to setting the timing there/s a arrow on the top of the alloy Mag back plate and a arrow on the rim of the flywheel to line up with piston about 1/4" before TDC

According to the manual timing can only be accurately set with piston visible.  Not had a MK15, but I believe the flywheel is feel to rotate on the shaft - which is how you adjust the timing to get points opening at the right place.
1955 manual states 3/16" BTDC 1956 manual states 1/8" BTDC

Woodsman wrote:

mattblack wrote:What manual do you have? I have the genuine Villiers one covering the MK10, 12 and 15 in PDF form if you want a copy.

Interesting. I have a manual covering MK10 and MK12 dated 1957 and two separate ones for the MK15 dated  1955 and 1956. What date is yours?

I have Mk.15 (VEC 31) Jan '55 and Mk. 10 & 12 (VEC 84A) Dec '56

Can't see a date on my PDF copy but it gives the timing as 1/8" BTDC and how to set it.

Extract from Jan '55 manual

Got there before me Stuart

Thanks everyone! What a resource to have at hand. Every comment really helpful! I've just noticed that my manual is dated "September 1956" - a month after I came into the world...It's a good manual but does say to only remove the crank if absolutely necessary. I got the flywheel off (easily once I got Pete's advice) using an impact socket - I had the completely wrong idea and am glad I didn't continue on my original course! I now have the flywheel off and can see a small male thread that's the beginning of the HT lead - part 217 on p.19 of may manual called "1046 x 13E Pad, H.T terminal" - a mouse chewed through the HT lead, the only real damage to a Bantam that has sat in a shed for at least a decade. I'm hoping I won't have to replace the whole coil...?

I think that the crank bearings and seals are OK - the engine was filthy and I think the main leak was via a paper gasket between the magneto case and the block - so would you bother with removing the crank in this case? I totally take Alan's comment re. quality of replacement bearings - I generally go for the most expensive listed on Bearing Boys. If I don't replace the seals I can avoid removing the crank - the shells look in good shape - I have some plastigage but the manual I have does not give a clearance and does not specify torque settings for big end bolts - am I over scienceing this whole exercise? I want to give the engine the treatment it deserves coming from a bygone era when this country had a real place in the manufacturing world before the bean counters muscled in on the act.
My manual definitely says 1/8" before piston reaches the top of its travel...
Many many thanks gents!
Neil

neilphilip wrote:

- am I over scienceing this whole exercise?
Neil

In my opinion yes you are, most early manufacturers didnt use torque figures for fixings etc, just use common sense, dont worry about bearing quality, if you display or use it theres no point waisting money on expensive bearings if you are only going to give it light duties like rallying and the odd garden dig.

Maryalice

Do you have a industrial/engineering supplier near you? They should be able to match the bearings. I got the ones for my MK12 (IIRC) from a local place, they were the sealed type but I removed the seals and washed the grease out.
As for the big end, just nip it up with a ring spanner and then to the next castellation to get the split pin in, don't go mad with a ratchet and it'll be fine

HT lead here: http://www.villiersparts.co.uk/ignition.html

Yours should be the 1/2" one I believe. You may be lucky with the coil, my MK15 and MK12 were OK, my current project MK20 was dead.

Or here

https://villiersservices.co.uk/index.php?main_page=product_info&cPath=8_18_61&products_id=535

And get your lead in bulk - bound to need more