Morris Minor Owners Club

Ok, now this is probably going to be obvious to one or two of you (probably all of you).

I have been trying to get my car running correctly, in that she seams to have been showing signs of running too rich. she is leaving black spots where ever I park her and then restart her, the exhaust does seam to be a blue/grey colour even once warmed up, when following the manual its telling me to lift the piston and se how the engine is affected, so have had a go at adjusting the mixture.

racing engine - too rich,

if it stalls - too lean,

so I backed the adjuster off one flat - lifted the piston a small amount and the engined dipped a bit one more flat and it stalled, so I ran it back two flats to where I started, then lifted the piston, the note changes but the engine seams to cope ok without racing, so then I started to tighten, which is to richen the fuel mix and then it did start to race a bit when lifted, but surely the black deposit means its too rich.... ?

However, if its not the fuel mix causing the blackness what else could it be - burning oil? would this mean a valve problem?

I know I have an oild leak that is getting quite frustrating as it can go from max to min on the dipstick in a week only on short runs, the previous owner (who is a famaly memeber) thought it was the covers on the side of the engine and had bought the seals to replace, but looking at the oil it seams to be all above that area too, so I would think its leaking from higher up. Any thoughts would be great.

Im thinking as I have an-other one, I may drop the engine out - re-build it then do a swap for the time being as this is looking like it needs a bit of a rebuild. Mind you the other engine runs and starts very well, doesn't show the same symptoms, so I might just throw it in.

l don't know, any thoughts?

regards

Nigel

If it is running too rich at idle you will get lots of black smoke puffing out. Black soot spots are not uncommon. I don't think you have a fuelling problem by the sounds of your description you can set the idle mixture OK. This will change as soon as you drive anyway. There is a bout a litre of oil between min and max on the dipstick so it may be the engine is burning oil too rather than just leaking it?

Are you sure you are turning the adjuster the correct way ? Is it an SU carb - with the exposed jet, and 'nut' adjuster? In which case - scewing it UP leans the mix, and screwing it DOWN richens the mix. The effect should be obvious - the lift pin is only to be brought into contact with the piston - then lifted 1/8" inch to get an effect. Rising speed = too rich, so scre the nut UP. Slowing idle = too weak, so screw it DOWN to richen. TBH - 1 flat of the nut either way is not usually significant! Better judge of overall running mixture is to look at the spark plugs - immediately after a good hard run. Ideally - switch off at speed and drift to a halt - and pull the plugs. Black = rich, white = weak, tan/beige is just right! With hot engine at idle - take the oil filler cap off - is there a plume of smoke/fume ? If so - it needs at least rings if not a full rebore. This fume causes pressure in the crankcase which forces even more oil up past the oil rings - and out of every available gasket/seal. It can be 'contained' to an extent by arranging for the engine to eat it's own fume - with a pipe connected to the carb, or even directly to the inlet manifold via a 1/8" restrictor. This definitely helps - but is only a temporary fix - it really will need a rebuild.

ok thanks BMC, I will drive it to work tomorrow and then whip the cap off and check for plumage of smoke/fume and I may whip out a few plugs at the same time to see what they look like after a run. I am learning lots but I think this car is doomed to keep me mystified as she presents me with a new challenge every weekend.

Mind you I love it when some one gets in the passenger side and slams the door a bit too hard, she always hits em back with the glove box door on the knee