12 replies to this topic

[chrisblackmagic]

just returned my 1983 mini mayfair 998 to the workshop, as I have come across a problem, I have just refitted the exhaust downpipe, started her, and she was running lumpy and there appeared to be smoke being emitted from the exhaust, I checked the plugs to find that number one and two were oily, while three and four were sooty, I have now run out of knowledge and the Haynes manual shows no solution, anybody have any idea what the problem is? cheers in advance

[Tommyboy12]

Sounds like a really rich needle setting to me.

[KernowCooper]

Did it smoke previously ? sounds rich and if you seeing a bit of blue its either valve stem oil seals/worn guides or worn bores which is the oil you see on the plugs, post a picture of the plugs if you can

[chrisblackmagic]

ok cheers, I will take a picture of the spark plugs tomorrow, and will have a look at the carburettor while I am at it!, will report findings tomorrow!

[DILLIGAF]

Check and adjust the valve clearances.........

[Captain Mainwaring]

just returned my 1983 mini mayfair 998 to the workshop, as I have come across a problem, I have just refitted the exhaust downpipe, started her, and she was running lumpy and there appeared to be smoke being emitted from the exhaust, I checked the plugs to find that number one and two were oily, while three and four were sooty, I have now run out of knowledge and the Haynes manual shows no solution, anybody have any idea what the problem is? cheers in advance

 

What did you do to it in the workshop? 

[chrisblackmagic]

hi, captain Mainwaring, had only replaced the exhaust downpipe outside, then put her back in the workshop where shes kept out of the elements, I will have check valve clearances next time I am there, later this week, here are some pictures of the spark plugs, 1-4, they have been in there while the car has been stored for 16 years, so would new plugs help?, however these have been cleaned once?

[Tommyboy12]

Thats a very rich mixture. Although, unless youve spilt oil on that second spark that cylinder definitely has some sort of oil leak.

[KernowCooper]

Plug 2 is a bit oily but seriously running rich, i'd compression check it and then sort the mixture and take it for a run and see what the plug reading are like then.

[jaydee]

Also fit a set of fresh plugs

[chrisblackmagic]

thank you for your advice!, will hopefully help me to get her on the road asap, plan as of now is to, sort out mixture, do a compression test, then run the car for a good while until its up to temp so not on choke? then have another look at plugs

[Tommyboy12]

I would do this in this order:

 

New plugs (or at least clean your old ones)

Set tappets

Run engine and check timing

Adjust mixture once hot

Compression test after engine is hot

 

Compression tests readings will be more accurate with a hot engine. You can check ring seals by putting a teaspoon of oil through the spark plug hole and redoing the test.

[Captain Mainwaring]

If this car is just driven outside and then back in again, I wouldn't take any notice. You can't get any idea on a car that is left standing for ages.

 

I'll bore the arse off you with an anecdote about my old Bonnie - if that gets started and then put back on the side stand. it'll oil the left hand plug overnight and it won't fire on that pot....everything is in spec but enough oil floods the rocker box to run down the valve guides and wet that plug - leave it on the center stand for long rests and the plugs are fine.