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Stuck flat blade screws in Villiers MK10 backplate

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Chris.R Thu, 26/11/2015

Hi,

I've recently acquired a Villiers MK10 (the early version) that has not been run in a very long time. I have tested the coil and found it to be completely dead on the secondary winding. I removed the flywheel and backplate to reveal the bolts for the points and 4 flat blade screws for the coil ears. No matter what I do the latter will not budge. I have tried WD-40, light use of an old impact driver and tapping them with a hammer, a few were already stripped but the others were so soft they just stripped when I tried to unscrew them. I'm using a perfectly sized screwdriver. Do you have any ideas as to how to remove them? I don't really want to drill them out because I'm not too confident and sourcing a replacement may be quite hard. I might post some photos later.

Many thanks,

Chris

Forums

hillsider Thu, 26/11/2015

Hello and welcome to the Old Lawnmower Club,

it seems as though you have tried most of the usual methods for removing tight screws, I am not too familiar with the positioning of the screws but photos would help there.

If you can get a clear view of the threaded ends on the reverse of the back plate you could try applying some gentle heat to the area around the bolt ends to expand the metal around the bolts releasing the threads. Don't go too heavy though or you could damage the insulation on the coils.

wristpin Thu, 26/11/2015

A possibility would be to grind or drill the heads off. You should then be able to remove the pole pieces from the backplate and then remove them from the coil core. There could be a couple of small grub screws holding the pole pieces to the core and from memory they are very soft and the slots tend to break out.

Once it's all apart and the coil safely out of the way you can be a bit more adventurous with heat etc. 

 

 

 

hillsider Sat, 28/11/2015

If you do take the drill the heads option you will only need to size the drill to the bolts shank diameter, this will make it a bit easier to keep the drilling near to the centre of the bolt head.

In theory as soon as you are through the head thickness the head should either fall off or be easy to break off.

 

Chris.R Sat, 28/11/2015

Hi,

Thanks for your quick replies, I drilled the head off of the bolt and then used heat and a pair of pliers to remove the stud left over. They are all removed thankfully... The only problem now is I am left with no bolts, does anyone know where I can find them or know the size of them. I don't have a thread gage to test the thread size. They seem to be metric and are about 3cm in length with a 1cm shoulder at the head.

Thanks again, Chris

wristpin Sat, 28/11/2015

Doubt if they are metric as the UK probably didn't recognise the existence of the metric system at that time !!  

Possibly BA  ( British Association ).  Recently did a rebuild on a machine with an old JAP two- stroke and the studs and nuts holding the lump to the chassis were Cycle Thread!

Edit

How wrong ...........

Was thinking about your screw size issue and Googled BA scre sizes only to learn that the BA system was based around metric sizes!!

https://en.wikipedia.org/wiki/British_Association_screw_threads