Help with 39 plymouth idle/mixture problems

a ford 2100 series carb is a pretty bomb proof carb. It may need to be jetted down a little for your flatty, but is very simplistic, rugged and easy to tune.

cheap too.

 

put in a new thermostat and problem solved!!! I think the old one was stuck open or something. He loved the truck! and I think there is a dual carb setup in going on in the future
Thanks everyone for the help!!!

 

wow- thats cool you got it figured out!

 

Its a problem that arises often with headers on a lot of inline engines....poor heat transfer to atomize the air/fuel mixture. Certain atmospheric conditions exacerbates (low temps/high humidity) a larger temperature drop within the intake manifold.....remember the carbs venturi affect drops the temp so low it actually freezes within the manifold which will cause the engine too literally run out of fuel.
You simply need too transfer heat too the intake.....the plate as described from Langdon can also be modified for exhaust heat instead of coolant.
On my 235, I have Fenton headers and a dual carb Offy intake.....I use the coolant plate and have fabricated a heatshield and ducting hose attached too it to draft hot air into an air cleaner snorkel as the engine warms....then a bi-metal strip senses when it is hot enough and the snorkel trap door (using engine vacumn) shuts the heat off too draft cold air......any 70's or 80's vehicles have this setup. By then the coolant is plenty warm too transfer sufficient heat to prevent carb icing.
Believe me....I live in British Columbia with cold damp temps frequently and drive my stovebolt 12 months a year.
Hope this helps...Cheers.

 

Oh ya....awesome truck by the way!!!

 

Thanks Helilog, we will see how she runs in some colder weather and maybe install something as you described...it was warm yesterday so that did help.
jay