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Following on from my Howard post, I am pleased to have acquired this Allen Scythe “T” or “TS”. On initial inspection it is complete and original and all moving parts are not sized, which is a relief. This “Allen” would be very useful at the allotment especially if I can get some of the tools that could be fitted to the scythe?
During inspection I was informed that it did not generate a spark and that it may require a service, which I planned to do anyway.
Having done my research before I took anything apart, it became clear that I should pay particular attention to the “timing” and take detailed notes as I removed items.
Much has been said about the timing marks on Villiers engines and whilst I believe this to be a MK25C 2 stroke fitted on my “Allen” I cannot see any timing marks at all (the red marks are mine) apart from the mark on the end of the crank shaft.
I noted that the beginning of the magnet in relation to the coil and made a mark on the flywheel next to the “tab” located on the base plate, before removing, which fortunately came off with relatively little trouble.
Having got the coil base plate off I inspected the points and these seemed to be in good condition other than they seemed to be sticking, as in a sticky substance on the contacts, which was cleaned off and then filed down to make a flat surface.
I then turned my attention to the “capacitor” (I’m a radio armature) and found that to be very leaky so I replaced it, so far so good.
Looking at the coil, it seemed to appear “new” but as we all know, this doesn’t mean the coil is good. So, once again this was tested and proved to be in working order.
Reassembling everything onto the base plate I installed it back onto the engine along with the fly wheel and using my strobe light first sought to determine if there was a decent spark, with a ground placed directly to the head, and to my relief, I had a very healthy spark, or should I say flash from the strobe light. However, the plug was not so healthy and with this in the head but not too tight only finger tight, the flash from the strobe light was very dim suggesting that there wasn’t a spark from the plug whilst in the cylinder.
So, checking the plug out of the cylinder the same dim flash remained on the strobe and nothing from the plug! Substituting the plug with a new plug used on my Stuart Turner R3 I got a bright flash and a healthy spark so now I need to get a D16 plug or similar.
Until I get a new plug I am still trying to get the correct timing alignment and considering that the only mark I can see is on the crank shaft, I set the timing as to what it was before I removed the fly wheel but noted that the spark was generated in the middle of the magnet and the points opened at that same time driven by the cam on the flywheel.
This corresponds to TDC so the question now is, if I keep the fly wheel in position and rotate the crank shaft back until the crank shaft line, point to the tab on the back plate, would this then be 3/16 BTDC or in other words, the correct timing position?
As of yet I haven’t taken the head off to measure 3/16 as I want to get the plug first and make sure that it is sparking within the cylinder before I move on to anything else, one step at a time!
So, hopefully some of the members will be able to confirm the engine type, Villiers MK25C or something else, a T or TS and when was the likely manufactured date?
More to come………………………….
John
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