I can get it going (roughly at first and with a few carby backfires) and when warmed up she runs fine, but the last few days the first starts after she's been sitting idle for a while are a bit rough. It will turn over, then stall and no matter how much choke does the same thing

I've gone thru the usual suspects like points and spark plugs checked etc, but in the Haynes manual it says it could be worn or sticking choke. Any clues on what to check for with a dodgy choke please? would it be the cable or the carby??

cheers in advance for the hints

Steve check the choke mechanism is operating correctly on the carbie.

The best way is to get an assistant to pull out the choke (engine off) while you watch what happens.

The first half of the choke movement a little cam should act on the throttle to increase idle speed. Make sure the little adjustment screw is not touching when the choke is right in/off.

The second half of the choke (pulling right out) should further increase the idle speed but also should cause a lever to move the jet base at the bottom of the carbie down thus increasing the mixture.

If you pull the choke right out and you cant see the jet move down then you are not getting any increase in mixture for startup. Might require some cable adjustment.

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68 Morris Cooper S Mk1 (*ex 78 1275 LS 4th last built, 70 Morris 1500 OHC & 70 MiniMatic)

Steve check the choke mechanism is operating correctly on the carbie.

The best way is to get an assistant to pull out the choke (engine off) while you watch what happens.

The first half of the choke movement a little cam should act on the throttle to increase idle speed. Make sure the little adjustment screw is not touching when the choke is right in/off.

The second half of the choke (pulling right out) should further increase the idle speed but also should cause a lever to move the jet base at the bottom of the carbie down thus increasing the mixture.

If you pull the choke right out and you cant see the jet move down then you are not getting any increase in mixture for startup. Might require some cable adjustment.

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68 Morris Cooper S Mk1 (*ex 78 1275 LS 4th last built, 70 Morris 1500 OHC & 70 MiniMatic)

thanks for that Phil

might have to do it at work tomorrow as it 's just me and the 9 year old daughter here just now ha ha

& seeing as you`re probly going to attack the choke first

after that i`d be looking into at least the oil in the dash-pot & at least giving the carby "piston & bell" a clean (the dash-pot assy)

they are often over-looked & when they get all dirty they stick

typical mini SU carb dramas

but now i`ve said all that it`s probly all to do with bad fuel or some other crap

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No offence intended here but--> anyone writing a book about minis 30 years ago may not have experienced such worn or stuffed-with components as we are finding these days.

You should put your heart & soul into everything you do.

well I just my 9 year old assistant to pull with all her might on the choke and yes, it does seem a bit tight on that lever on the jet base at the bottom of the carby and also at the top of the pin that connect it next to the return spring.

I've just sprayed the hell out of all them bits with some penetrant and will see how she goes 5.45 in the morning! Sorry neighbours, wife and kids!

she had a good tune up from Greame Lord 3 or 4 weeks ago, but has just started this the last few days - I don't wanna have to take her back for another tune up again. The wife is already not too impressed with my Mini expense account

if you can lube inside the cable (maybe remove & lube & re-fit) that also may help & save the need to buy a cable sooner , rather than later??

maybe?

depends where the sticky bit is, either the linkage or the cable,,, maybe both

if the carby piston & bell assy has already been cleaned then disregard any of my earlier post

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No offence intended here but--> anyone writing a book about minis 30 years ago may not have experienced such worn or stuffed-with components as we are finding these days.

You should put your heart & soul into everything you do.

thanks Mini Man

will try the cable lube at work tomorrow - very grateful for a sympathetic boss and it being quiet at work and the fact I can work on it in the store room ha ha

A mechanic that used to work with us ( older gent ), told me one day that years ago when he used to muck about with cars, that he used to polish the carby piston's with toothpaste.

Toothpaste is a great polish - used it for many things including getting fine scratches off watch glass, and removing haze from old acrylic headlight covers - works a treat!

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Cooper S Mk2
Cooper S Mk1
ex Cooper S Mk2, various Morris 1100s, 1300s, 1500s, Leyland Sherpa!

it appears this seems to be sticking either in or out - ie not moving too freely

any hints on what to lube it with?? - have put some grease on it for now but doesn't seem to be achieving much - tis a bugger to get going in the mornings for now tho :/

I would just give it a squirt on each end with WD40, try and aim the tube so it blows into the cable. Then give it a few tugs.

If that does not fix it remove the cable and then remove the inner smear it in oil and push it back in and install the cable.

I recently had to remove my choke cable and re-lube it after I cooked it! I managed to sit the cable onto the positive battery terminal (Morris 1100 has the battery under the bonnet) while I had a carby removed with the cable still attached.
The whole cable was glowing red! When it cooled down it was very stiff to use (not surprising!) but when I oiled the cable it returned to normal.

The choke mechanism on the side of the carby also needs lubrication every now and then. Just a couple of drops of oil will do it. I just pull out the dipstick (when the oil is fresh) and let a couple of drops fall onto the linkage.

"STP" is the best stuff to use for both the mixture jet tube & the choke linkage, & even the throttle & choke cables too,,, but to do the cables effectively they need to be un-attached & slip the inners out to lube , then re-fit

i love the stuff,,, we call it "Sticky Tacky Poop"

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No offence intended here but--> anyone writing a book about minis 30 years ago may not have experienced such worn or stuffed-with components as we are finding these days.

You should put your heart & soul into everything you do.