[vhgmcbuddy]

Yes filing a slot is a solution i thought of so would putting it on a lathe, even better, but i repeat only if one knows exactly where there original mark was, the crank had obviously turned and possibly moved every time the engine was pulled over thereby partially wiping out where it should be, but if i knew when ign occurred in relation to the coil and where piston should be i could solve the problem the other thing i could do is to make a key offset to alter ignition by 5deg but again we are talking time if it was my machine time is no relation to cost but when repairing for someone else it’s not worth the cost…………

[vhgmcbuddy]

You need to file a slot on the inside of the flywheel taper where the cast (integral) key was originally.You will need some needle files to do this.You will then have to make a key to fit the crankshaft keyway and now the flywheel keyway.

[vhgmcbuddy]

Sounds as though someone has saved you some fiddling around resetting the timing from scratch, cross fingers that the punch marks are in the right place. I concur with the the suggestion of having the coil checked out on a proper tester – even more so for the condenser: judging from the number that I replace after a dodgy test result it’s well worth doing. The problem may be finding someone with the right kit to do it – used to be essential in any small engine workshop but since the introduction of electronic systems it’s just chuck it and fit another!
I work on a lot of “unknown” small engines and nearly always start with a “top end” overhaul – aka a “valve job”, but there again I have the kit to do it. A lot of people spend ages fiddling with carburettion and ignition when the root cause of poof starting and running is out of adjustment and poorly seating valves.

[vhgmcbuddy]

Ref flywheel unfortunately the mark left by the key shearing was difficult to place exactly so it was just as near as i could get,as for getting a key slot cut it’s down to cost as well as position,cheaper to buy new flywheel but what is a ten year old machine worth £28+ on bay !,when i have come across this problem of key shearing before yes it’s mostly due to shock which on a hedgecutter is easily done,as for ignition what about the old B/S one’s where you can replace the coil and fit an electronic one and do away with point’s and condenser and still use the old flywheel and it work’s………….

[vhgmcbuddy]

Hi Wristpin, Thanks. Just seen your post re box spanner and it reminded me I’ve got a few I inherited somewhere. Just where? Also, a chap I volunteer with at the National Trust races 1960’s Formula Fords so should source one there, plus he’s currently got my welding mask on loan so owes me a favour. Cheers, Mick

[vhgmcbuddy]

Hi Wristpin, Many thanks for helping out someone who’s very much still wearing L plates with his first mower. I had a more careful look at the flywheel last night and there’s punched dots on the flywheel and the back plate that I hadn’t noticed previously. Took the head off to be sure and they correspond to TDC. Phew! Hopefully that will make cleaning, checking* & refitting the ignition parts easier and for an accurate set up. So will sort through a toolbox full of rusty “vintage” spanners in my Dad’s garage at the weekend. I suspect (hope!) there are some Whits in there and one of the right size. Failing that I’ll invest some £££ in acquiring one. Once again many thanks. Cheers, Mick
* I’ve just read your posts on getting the coil checked properly rather than just doing a resistance check. I am getting a spark and the engine has run but it’s difficult to start so I’ll just clean, set and make sure it’s fuelling first. I’ll get it tested if still problematic and the stripping & refitting will be good practice.

[vhgmcbuddy]

This single hex box spanner is available from L&S but CHECK the size as they only mention the larger engines

https://www.lsengineers.co.uk/villiers-heavy-duty-spanner-for-flywheel-centre-nut-mk10-mk12-mk15-em548.html

[vhgmcbuddy]

The m/c itself is scrap the gearbox was in pieces but I bought it for the grasscutter and the grass tyres
The engine is an Aspera now you mention it with a bore about the same as a Villiers 15

[vhgmcbuddy]

I’ll mark up the flywheel and crank before undoing the nut

You may find that Villiers have done that job for you. At some point in production they used to set the timing using basics such as piston position and points opening and then rotated the crank to Top Dead Centre and stamped an arrow on the flywheel rim to coincide with another reference mark on the flywheel housing back plate. If you are fortunate enough to have one of those engines, all you have to do is to clean and set the points to the correct gap (12 – 15 thou),turn the crank so that the piston is at TDC (probably best to remove the head to do this rather than at an angle through the plug hole), and fit the flywheel so that the arrow aligns with the mark.
The slight danger in making your own markings is that unless you are 100% sure that the “as is” timing and points gap are correct, you are just perpetuating a possible inaccuracy.
At the end of the day, if you have to re-time the engine by relating the piston position to the point at which the points start to open, it is not rocket science and one of us will talk you through it.
I totally endorse Trusty220’s advice not to use a open ended spanner on the flywheel nut and that a stout single hex socket or box spanner is the way to go, but if all else fails an old cranked Whitworth ring spanner is unlikely to harm the nut – but it must be the correct size of Whitworth spanner and not the nearest AF or metric! The correct “flogging/slogging” spanner is still available from Villiers Services for around £20 delivered.
villiersservices.co.uk

[vhgmcbuddy]

Hi Trusty, Thanks for the info. As per reply to Wristpin I’ll have a bash at it when I’ve found a hex spanner that fits properly. Cheers, Mick

[vhgmcbuddy]

Hi Wristpin, Thanks for the info, yet again! I’ll mark up the flywheel and crank before undoing the nut so as to reset the timing correctly. Will have a bash (literally) at it when I’ve found a hex spanner that fits properly. Cheers, Mick

[vhgmcbuddy]

That’s as it should be, the nut is captive to exert a force on the flywheel to pull it off the taper on the crank. Villiers provided a special spanner designed to be struck with a hammer both to remove and, equally important, to tighten it sufficiently to maintain the flywheels position on the crank to preserve the timing – there’s no key to position it.

[vhgmcbuddy]

Would it not be possible to get a keyway cut into the flywheel, using the witness mark of the sheared key to position it, and then use a loose key to align the two keyways? Assuming that the flywheel is a taper fit to the crank , it is the taper that does the work of keeping the flywheel in position, the key just provides the initial alignment.
There is, of course, the question of what caused the integral key to shear; the options being lack of torque on the flywheel retaining nut or an ignition fault causing a kickback, both options overcoming the grip of taper.
I’m guessing that your question about what actually triggers the spark on that electronic ignition system is one for the designers of the particular system to answer. Taking the Briggs and Stratton Magnetron system as an example , it has a visible additional trigger “pole” just before the coil pole pieces.

[vhgmcbuddy]

Well done. Just goes to show hens teeth do exist!

[vhgmcbuddy]

Thanks Charlie. Hopefully I can take her out next year without constant misfire and spluttering!

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