Just another Marvel question

[Steves Buick]

Well the other day I pulled  spark plugs and saw they were heavily fouled,  I know the Marvel on my 1932 96s runs rich, I've had it apart more than once. This time with surgical precision I went through it as my engine has has a slight cough at idle then sometimes a slight back fire under load, normally corrected by slightly pulling choke.  I replaced my points with petronics, works well so far, put it all back together and no change, still rich and still coughing under load. Mechanical advance seems to work via timing light, adjusted the valves, its timed right at 10 degrees BTDC. Wires checked good. compression is all in mid 80's. Pulls 18.5 inches of steady vacume at idle. I didnt see anything jump off my heathkit scope. 

So still scratching for a solution, But the question is on my carb next to the bottom of the  economizer plunger passage to the intermediate and high speed jets there is a needle valve that has no seat in an intersecting passage. The marvel overhaul manual mentions some carbs had a a check valve some where at the end of the passage??? 

 

Here's a photo, does any body know what its function is?  

 

Sorry to bring up another Marvel string, I've read all of them on the forum and didn't see this before.. 

Thanks,

Steve 

[Oregon Desert model 45]

The big Master parts list book has this diagram of a 1932 Marvel carb.

which part is that ?

 

Edited June 3, 2020 by Oregon Desert model 45
edit (see edit history)

[Steves Buick]

 Looks like 16-120, or 13-108,  I need to get a a master parts list, thats a great resource, Thank you..

Steve 

[Oregon Desert model 45]

here is the parts list for the 32 marvel.

The diagram in the book is very small so it takes a magnifying glass to read the numbers

[Steves Buick]

Thanks, great help..