Reproduction Parts for 1916-1964 Chevrolet Passenger Cars & 1918-1987 Chevrolet & GMC Trucks


Previous Thread
Next Thread
Print Thread
Rate Thread
Joined: Jan 2023
Posts: 7
axel Offline OP
Grease Monkey
OP Offline
Grease Monkey
Joined: Jan 2023
Posts: 7
i replaced my carb
i have a number 57 main jet
runs very rich
car runs good but does not run smooth
tail pipe very sooty

How do I adjust?

Last edited by Peter_Gariepy; 01/19/23 04:56 PM.
Filling Station - Chevrolet & GMC Reproduction Parts


Filling Station


Joined: Dec 2007
Posts: 3,956
Likes: 94
ChatMaster - 3,000
Offline
ChatMaster - 3,000
Joined: Dec 2007
Posts: 3,956
Likes: 94
I assume that the automatic choke is opening completely and that the float level is correct. Those would be the first 2 items to check. I also assume that you did replace it with a correct year Rochester carburetor.

I would also check for vacuum leaks as well as make sure the idle mixture screw is set correctly. I know that idle mixture does not have much if any affect on operation at speed but if the idle mixture is rich it will produce soot.

I do not know what size the main jet should be. Hopefully one of the experts will respond.


Rusty

VCCA #44680
Joined: Jan 2002
Posts: 30,673
Likes: 138
ChatMaster - 25,000
Online Content
ChatMaster - 25,000
Joined: Jan 2002
Posts: 30,673
Likes: 138
Typical problem when the vacuum power piston is either stuck, its spring is missimg or not recieving vacuum due to port between carb. base and intake manifold restricted by gasket or improper insulator under cabuetor.
To make a long story short power piston is stuck in the rich position.
First thing I would do is remove the carb. and see if the litle hole on the bottom of the card. base is covered up.
The correct insulator block under the carb. has four notches, one of them must line up with the hole under the base. f you have a gasket in this area remove it, it is NOT necessary.

Last edited by Chev Nut; 01/19/23 07:57 PM.

Gene Schneider
Joined: Jan 2023
Posts: 7
axel Offline OP
Grease Monkey
OP Offline
Grease Monkey
Joined: Jan 2023
Posts: 7
you are a genius!when replacing carb i did plug the port.repaired and runing great.thanks that carb is rtelativily simple but wish i could find technicial explanation. thanks again axel

Joined: Jan 2023
Posts: 7
axel Offline OP
Grease Monkey
OP Offline
Grease Monkey
Joined: Jan 2023
Posts: 7
i got a reply from chev nut.followed his advise and found and repaired prob.i had plugged port with gasket...tks axel

Joined: Jan 2023
Posts: 7
axel Offline OP
Grease Monkey
OP Offline
Grease Monkey
Joined: Jan 2023
Posts: 7
chnverted my chev to 12 volts.what is the resistor size to use for the fuel gage tks axel

Joined: Jan 2023
Posts: 7
axel Offline OP
Grease Monkey
OP Offline
Grease Monkey
Joined: Jan 2023
Posts: 7
thanks for reply.chev nut led me to a fix.i had blocked a port pn carb base while installing...fix and doin great tks axel

Joined: Dec 2007
Posts: 3,956
Likes: 94
ChatMaster - 3,000
Offline
ChatMaster - 3,000
Joined: Dec 2007
Posts: 3,956
Likes: 94
Do a Google search for 6 volt fuel gauge resistor. There are lots of sources. They are sometimes called a “Runtz” resistor.

You also might want to start a new thread when you change the subject. Otherwise people might not realize that you ask a different question.


Rusty

VCCA #44680

Link Copied to Clipboard
Support The VCCA!

Enjoy the forum? Become a VCCA member! The World's Best Chevrolet and GMC Club!


Member Photos
1964 Chevrolet Impala SS
1964 Chevrolet Impala SS
by DreamChevy, February 17
My 1933 Chevy 2 Dr. Sedan
My 1933 Chevy 2 Dr. Sedan
by 1939Chevy1, November 24
Back on the road 79 years later
2 1927 Chevrolet Trucks
2 1927 Chevrolet Trucks
by 1927TRUCKS, June 7
Who's Online Now
1 members (1 invisible), 51 guests, and 31 robots.
Key: Admin, Global Mod, Mod
Newest Members
RichR, Johnbon35, TekuEntity, sammyrhoden, Nick_in_Manitou
18,267 Registered Users
Today's Birthdays
Bob_Hill, etnfrd67, sixyearsdown
Forum Statistics
Forums58
Topics58,938
Posts428,203
Members18,267
Most Online1,133
Jan 22nd, 2020
 

Notice: Any comments posted herein do not necessarily reflect the official position of the VCCA.

Powered by UBB.threads™ PHP Forum Software 7.7.5