mixture screw on ma12 carb

[NathanHug]

i have recently got my car back from an MOT and the mechanic said that im running the wrong mixture to much air not enough fuel, i have heard something about a cover over the screw, could you guys help me on how to find and adjust my mixture thanks lad ino you lot can help

 

[sr20bud]

yeah its on the back of the carb if i remember rightly im pretty sure it has a spring and a hex metal cap over it

 

[porkpie700]

It has an anti tamper cap over it which can only be removed by cutting it off in such a way that you don't damage the adjusting screw itself. The mixture is set by the factory when the car is built and should never need to be altered, hence the anti-tamper cap. If the car runs fine then it is fine and shouldn't be disturbed.
If the car is not running fine then i would reccomend checking the condition of the vaccum hoses, as any leaks would cause an over-lean mixture.

Also check that the bi-metal switch (the valve with an orange dot on it) inside the airbox, to make sure that it isn't stuck open. The bi-metal switch opens when the engine gets above a certain temp and weakens the mixture slightly in order to prevent the engine from over heating.

 

[NathanHug]

so on the back of the carb yeah ? could anyone post a photo ?

 

[sr20bud]

i was wrong just looked at my carb and its round it looks like giant flat head screw it has like a round collar round it that has a metal pin down the side of it to stop it turning i think. and yeah its at the back of the carb at the bottom near where the carb bolts to the manifold.

as porkpie says tho it shouldn't really need to be adjusted as it doesnt move anyway.

 

[essexpunx]

If your cars running fine i'd leave well alone

 

[NathanHug]

i have had a look at it and it doesn't look like its worth the hassle thanks for the advice lads