1953 mercury auto choke replacement help.

Hey guys so I believe I'm in need of a new auto choke for my 53 mercury Monterey.

Here's the symptoms:
At random times I'll get higher than normal idle in the mornings till it warms up and when it's warmer the idle will randomly go lower almost to where it stalls. The idle seems to be fine most of the time but it does fluctuate from time to time.

If I'm wrong please let me know. So my question is where can I find a replacement? What all do I need to replace?

Any wisdom would be greatly appreciated.

Thanks,
George

 

Bump

 

Get a shop manual and it will tell you how to adjust the choke and the different idle and fast idle screws.

 

I don't think that's the issue though. Once it's set it shouldn't fluctuate randomly.

 

How is the choke thermostat heated? Hot air tube from the exhaust manifold? Heat well in the intake manifold? Engine coolant routed near or thru the thermostat housing?

I'd assumr there's a choke pulloff or vacuum break somewhere on the carb. Is it working and adjusted properly? Some pics of the carb, intake and linkages might be helpful.

 

I don't have enough info for the tea pot Holley carbs but I know that they are generally adjusted for a high idle until the choke control spring warms up to temp. Low idle should be adjusted after the temp control spring is a operating temp. Fast idle is generaly adjusted when the idle adjustment screw is on the fast idle step of the cam. It's been a while since I looked at one but it seems that the choke control housing is mounted on the intake manifold and attaches to the carb with a linkage. The earlier 885 had it mounted on the side of the air shroud but had to have vacuum from the venturi to draw the hot air up into the choke control housing. The later 51 up through 53 had them mounted on the manifold close to the exhaust cross over. If the crossover gets clogged with carbon then the choke is slow to function and sometimes doesn't function well at all,