[Mgs] cruise control

[PaulHunt73]

Something someone else said reminded me that with the air cleaners off and 
the engine stopped both pistons should be fully down, dropping with a smart 
'clunk' if raised by hand against damper resistance.  If that's not the case 
then something is binding.  If they are free as they should be, but one 
rises more than the other with the engine started and racing, then that carb 
is passing more mixture which could well be from its butterfly not fully 
closed.

Twin carbs should always be exactly the same i.e. be at the same position 
when stopped, rise to the same position when idling, rise at the same rate 
and to the same final position when the throttle is opened, and drop back to 
the lowest position immediately the engine stops.

If one carb butterfly is open more than the other then it will cause a high 
idle, but the question has to be how did that happen during a drive, as that 
is what I understand happened.

If the butterflies are fully closed then the engine won't run, they have to 
be open a small amount to allow a certain amount of mixture through to give 
the correct idle speed.  What you will have to do now is fully balance the 
carbs for both air flow and mixture from first principles.  That's mostly 
done at idle, but the most important part is that the air-flow remains 
balanced when the throttle pedal has just started to open the butterflies 
and raise the engine speed.

I note you attached a picture, these are deleted by Yahoo before sending on.

PaulH.

----- Original Message ----- 
> After taking off the air cleaners and starting the car (still idleing
> between 2-3000rpm), I see that the front HIF carb piston is probably 1/4
> inch higher than the rear.