Hello, I am currently working on a 1968 340, The car will start and run ok from cold with the cold start operating as it is designed to, However it starts and runs without the cold start connected, Can anyone point me in the right direction please?

 

If the car starts from cold, when the cold start is disconnected, then it sounds like your carbs are running way too rich.
Where/how is the cold start disconnected ?
Or are you disconnecting it just to see ?

 

Disconnecting the Otter switch connection

 

Otter switch ????
You mean the thermostatic switch on the water jacket near where the thermostat is ?
If the car is in a heated garage then it also may start with out it being choked, but even in a heated garage with out it being choked, it will start poorly _ or at least it should.

 

Otter Switch/ Thermostatic switch !! yes same thing , It is not in a heated garage, but starts and runs no problem without the switch connected, With the switch connected it starts and runs at a fast idle for a few minutes until the choke cuts out then drops to a nice even idle,

 

Otter Switch _ never heard it called that before...
If the car is drivable/reliable, are you able to take it for a longish drive once it's warmed up ?
If you can, don't let it warm up in the garage, drive it as soon as the oil pressure comes up (about 5 seconds).
Drive it gently until the temp gauge shows a normal operating temperature.

After it's cooled down (the next day) pull one of the spark plugs out _ I'm guessing it's black and sooty from running too rich.

And you're in a place called Forfar, looks like Scotland ???
I have you at 9 degrees and rainy _ not that warm _ it should not be starting with out the choke _ this basically points to the carbs being set too rich.

 

Hi the car is not quite ready for the road yet so that side will have to wait, however I have set the carbs according to the manual, will double check the settings and do a plug check as soon as I can and see where I go from there, mean while thanks for your advice, Yes I am in Forfar Scotland and its hosing down, good weather for the migrating geese, Check out SNG Barratt website and look for the Choke Otter Switch, Good site not a lot they dont stock, regards Kenny

 

Don't worry about the mixture settings for now, wait until the car is ready for the road.
With out checking the manual tells you 3 1/2 turns from fully seated with the screw(s) at the back of the carbs and generally I find that's too rich, but until it's on the road, it can't be adjusted properly.
Don't keep starting the car unnecessarily, more then 90% of engine wear is on cold start up.
People who leave their cars sit there and idle for 15 minutes are doing more harm then good.

When it's on the road and fully warmed up, the rule of thumb is to back each screw off by 1/4 to 1/2 turn until it's just starving for fuel (it will begin to idle rough).
At this point turn the screws until the idle smooths out and then give it 1/8 more of a turn.

And our weather today here is actually sunny and a little cool, but warm for mid November.
Today is our remembrance day and it always rains on this day, so the sun is a nice treat.
I'm going for run this afternoon (lots of forest logging roads and trails) and contemplate the day and my two uncles that fought in the second world war _ one of which is still alive.

 

OTTER is the brand of the original thermostatic switch, they've always been called that.