Hi idle when warm

[JSabah]

My car (‘49 Flathead 6 218) starts up as it should but it seems that after it warms up, the engine idle doesn’t lower. It actually seems that when the car initially warms up, the idle does drop but then after a bit more time, the Revs get higher and It does want to kick down.  I have duel carbs from Langdon’s Stovebolt 32/36 progressive on the heated manifold. I think it must be a carb adjustment, but which one? 

Edited June 22, 2020 by JSabah

[busycoupe]

I think that I would start by backing off the fast idle settings then adjust it so that  it idles correctly when fully warmed up.  Turn it off and let it cool, then restart  and adjust the fast idle warm up settings.  It may take several tries to get it to warm up and idle properly. 

[greg g]

There is a small piece of linkage from the choke that engages a small ramp that is the high idle setting. Make sure the choke is fully off when warm, and the little ramp disengages with the choke off.  Normally resetting it to hot idle speedl requires blipping the gas pedal after warm up is complete. Likely something is missaligned or sticking, so check, clean, lubricate those assemblies.