Morris Minor Owners Club

I've been continuing to slowly go through the mechanicals of our new Minor. Last week I replaced ignition parts (plugs, leads, cap, rotor, points) and did a compression test. While doing this I noticed that the plugs had a very uneven color, after a 10 mile test drive. Plugs 1 & 2 look good, beige in color, while 3 & 4 are really black. The car runs well, but I have noticed a puff of smoke when I give it some throttle after sitting at idle for a short while. I do not know how much oil it burns as I've only done about 100 miles in it as of yet.

I will add some links for pictures of the plugs so you can take a look for yourselves:
https://postimg.cc/K1w0Yxj0
https://postimg.cc/YjMb0X2B

I mentioned that I did a compression test as well, here are the figure (hot engine, valve clearance at 0.015"):
Dry/Wet
Cyl 1: 155/165
Cyl 2: 165/180
Cyl 3: 170/175
Cyl 4: 175/180

These figures were actually alot higher than I expected since the engine is in unknown condition and was "stuck" sometime in the 80's according to the previous owner. Cylinder 1 is a bit lower that the others, what do you think of the figures?

I'm unsure about what is causing the uneven spark color, should I be worried/investigate further?

Thanks!

Really black is not a good enough description.

Black, dry ‘sooty’?

Black , oily and a hard coating?

Two considerably different symptoms (or is it signs?).

Could be a few reasons for the difference, but more into required before guessing unnecessarily.

Most likely is oil going down the guides (blue smoke after idling).

I think the pictures might be better than my description, but I would say more towards the "dry and sooty". I do not think that the (slightly?) lower compression on cylinder one has any connection to the other signs, just thought that compression could be useful info in this context.

Looks shiny to me, so more likely to be oil than soot.

Phil

Thanks for replying! I have no great experience in this matter so any input is appreciated!

I found a picture of the plug from cylinder # 4 as well. I think that looks even more oily:
https://postimg.cc/zb2p8DZX