Setting the distributer drive cog - and close to giving up!!

[rayofleamington]

Firstly congratulations for fixing it

So I have no idea what's wrong with the first distributor, I guess I'll dismantle it and see sometime, but after the three or four days it's wasted for me I won't be in a hurry to experiment! (And I can stop feeling completely incompetent!)

Possibly a poor connection between the points mounting plate and ground? That can cause all kind of ####. I've only had that once and it was on a motorbike, and I started playing with it at the top of the biggest hill in a 10 mile radius from where I lived, quite near a trig point - you can guess the outcome... bottom of hill and still not started.

Badly earthing points mounting plate is not unheard of with Minors, albeit very rare - most likely culprit is the little (often unseen) grounding wire.

It may have been assembled 180 degrees round relative to the offset dog on the drive spindle. Thus the sparks would be 180 degrees out!

That makes no difference if you follow common sense. With #1 on the compression stroke (checked using finger on the spark plug hole) the position of the rotor arm shows you exactly which terminal on the dizzy cap to use for #1 spark plug lead.

[bmcecosse]

Yes -if that was done correctly! But we are told the flames were coming out of the inlet ports, so it obviously wasn't correct timing - but it obviously WAS sparking, just not at the right time. Straight swop sorted it - can't see any other explanation than 180 degree difference in the dizzy.

[alzax3]

The fact that it started working instantly a functioning distributor was fitted in place of the original would suggest that it was being done correctly from the start really, wouldn't it? And during the several days of messing around with the one that wasn't playing ball I did even try briefly setting it at 180 degrees out - that just resulted in 'pumping' back through the inlet with no flames or anything else resembling ignition. With the faulty distributor mounted properly I could (with the manifold removed) get flame from either inlet or exhaust ports with maybe 10 degrees of rotation of the distributor, but at no point did the engine ever actually 'fire'.

(I'll check out that grounding wire - it looked to be attached properly, but it's nearly as old as me so could well be worn out with the effort! )

[bmcecosse]

Well - if the old dizzy was sparking, then there wasn't much wrong with it. Just a timing issue. Did you use the same cap and leads with the 'new' dizzy - or did it come with it's own set ?

[alzax3]

Yup, same cap, plugs and leads, and for that matter contacts and condenser that had already been tried on the faulty distributor. As I've been trying to make clear, the faulty one gave every impression of working, it just would not cause combustion however it was adjusted in relation to the timing. The new one simply works - if it was 'just a timing issue' then 4 days of fiddling would have found it and I wouldn't have needed to post the question (and if I'd picked the working one out of the parts bin I definitely wouldn't have had to!

[bmcecosse]

I'm sure you are right - but it WAS sparking! Never mind - be happy it's working now. Don't suppose you are inclined to refit the old dizzy and give it another try! No ? Thought not - perhaps best just to bin it before it annoys you any more!