[landowner]

I wouldn't worry too much about the leak, let it develop and enjoy the car
If it gets worse then you'll be able to see where it's coming from, it's not going to do any damage
Head gasket usually leaks from further along near 1 and 2, if it's gasket then just use it till it's fooked and then swap it.

 

[DanClarke]

Um have you cleaned it to see if it comes back?
Clean it up.. start engine.. watch for progress

Several times. But it only appears after a run. I want to believe it's the rocker gasket, but I can't find any oil ABOVE the plug well so far.

 

[kermit_rr]

i think its the rocker gasket

 

[badfluffy]

for the price of a rocker gasket change it and find out

 

[Stanleysteamer]

It is a HIF44 SU carb.
I am willing to believe it's the HG, but I cannot track the oil down from there so far.
If it was a cracked head etc I would expect other symptoms too. No blue smoke or steam either, but the radiator was a bit low when I checked it yesterday so I suppose it is possible. Hotter plugs @Stanleysteamer I had thought of that its got BPE6's in ATM and I have a new set of BPE5's I can try.

You could also try weakening the mixture a tad.
Did you pull the plugs after a decent hot run? I seem to remember before, you were happy with the colour of them.
You could always do a compression test, if that cylinder is down on pressure then things need investigating unless you CBA and just want to enjoy it for a bit!

For oil to be coming out of the plug hole there has to be a leak at that point AND there has to be availability of oil to it inside the head.
Does the plug come out or go back in any "different" to the feel of the others? Has it been crossthreaded at any time as far as you can see?
Loadsa threads available on how to fix it if it is bad, i.e. beyond just chasing it back down.

Google Search

 

[landowner]

If your oil is very clean then maybe you can only spot the bit that has run down to plughole and got dirty

 

[DanClarke]

OK it is time to "fess-up". It was the rocker gasket after all.
The LH screw-down T-Bolt was not as tight as the RH side one.
One extra quarter turn (to match the resistance felt on the RH side one) and the leak stopped.
So well done all you gasket's-borked callers (Henry, Dippypud etc.)

 

[kermit_rr]

OK it is time to "fess-up". It was the rocker gasket after all.
The LH screw-down T-Bolt was not as tight as the RH side one.
One extra quarter turn (to match the resistance felt on the RH side one) and the leak stopped.
So well done all you gasket's-borked callers (Henri, Dippypud etc.)

Henri

 

[DanClarke]

Henri

Stirrer!

 

[Stanleysteamer]

Henri

Euh, 'allo 'Allo!!!

 

[Stanleysteamer]

Steel tres étrange zat you did not spot it running dahn zee sahd uv zee engine top!!

 

[Stanleysteamer]

OK it is time to "fess-up". It was the rocker gasket after all.
The LH screw-down T-Bolt was not as tight as the RH side one.
One extra quarter turn (to match the resistance felt on the RH side one) and the leak stopped.
So well done all you gasket's-borked callers (Henry, Dippypud etc.)

Glad you sorted it!

 

[DanClarke]

Steel tres étrange zat you did not spot it running dahn zee sahd uv zee engine top!!

Yes indeed, it left no trace. The oil is still clear from the last change so no black trail.
I did put a tell-tale there and it came away clean and dry (still is) but after tightening the cover T-bolt a bit more the seep/leak has clearly stopped.

 

[DanClarke]

OK, so here are the very sooty BP6ES plugs. All equally awful, no special standout cases.

I shall pop some BP5ES's in (hotter plugs I think). I hope they don't do any damage, and it might burn off the carbon.

 

[kermit_rr]

I've seen worse

 

[landowner]

OK, so here are the very sooty BP6ES plugs. All equally awful, no special standout cases.
View attachment 343227
I shall pop some BP5ES's in (hotter plugs I think). I hope they don't do any damage, and it might burn off the carbon.

If it's not smoking and burning oil then that's a bit rich, post a pic of your needle next chance you get please

 

[kermit_rr]

If it's not smoking and burning oil then that's a bit rich, post a pic of your needle next chance you get please

A bit rich but that's ok if it's been idling

 

[landowner]

Most common carb needle in the day for a 1275 was a DZ, used by Austin, Riley, Morris etc for their standard 1275 motors with single inch and a half (38) carb BTW.

 

[Stanleysteamer]

I think we are beginning to say the same thing now.
Weaken the mixture a bit, and or change the plugs. If the engine really is a standard as it seem to be, now, I'd go with weaken ing the mix a tad to begin with.

OK, this is for bikes, but a good explanation of how to do plug cuts or "chops" as some say. (you have to read more or less all of it. but it isn't long. )

Spark plug reading -plug chop method ?

94 L model, 6000 miles, original plug, I think. Right now I have a stock carb with dynojet kit with a 160 main, needle supplied by them with a E series muffler at 5 disc. ON the E, the less disc the richer, more leaner, so instead of changing jets this would be the easiest to do first. Now I'm at...

www.thumpertalk.com

I think you only need to do the WOT one as it is on a SU. i.e. hard foot down through the gears then in top hold it open as long as you can before standing on the clutch and cutting the engine. you do obvs need to plan where you are going to coast to a stop.

A dual carriageway with a layby is what I use.

 

[Stanleysteamer]

Don't know if this would be any use as I think you are probably on the right needle now. And I apologise for having told you the needle for an MG Metro, altho TBH none of us knew it wasn't an MG engine.

SU Needles Chart & Comparison Tool | Classic Mini DIY

Compare SU carburettor needles for your Classic Mini with our interactive chart. Find the right needle profile for your engine build.

www.classicminidiy.com

Active comparative site.

Helps you "try out" various needles