Can someone tell me how to adjust the fuel mixture screws on a 77?

Thanks in advance..

 

Anyone??

 

If you are asking about the air-to-fuel ratio at idle (the two screws at front of carb base).
Well; there's a lot to it as a whole.


But; just at idle here is the old fashioned way....
The very basics/starting point:
start with a known *correctly* working carb and no known vacuum leaks..
1>add a vacuum gauge and an under hood tach.
2>slowly screw in until you lose RPM's

3>Then back out until you gain RPM's and get a noticable steady reading on your vacuum gauge.

Do each side...then go back and do each side again...thats about the best you can do at idle with simple tools.

If you back out too far...you will lose RPM's again...screw in a quarter turn at a time until you reach the highest amount of RPM's and a steady vacuum gauge reading.

Thats the basics only.
This was done in the old days "by ear" listening to the gain in RPM's.
The main goal if you are not real familiar with carbs is to reach the highest amount of RPM's and a steady vacuum gauge reading along with the highest amount of vacuum.


Different carbs, adjust slightly different...some adjust fuel, while others adjust air...since you didnt mention which carb...the above is Rochester QJET.


If it requires more; you will need a little more technical tools.
If you have a malfunctioning carb or vacuum leak...you will NOT get the correct A/F ratio until the problems are resolved.

Also; any other further repairs to correctly adjust idle A/F ratio, and WOT A/F ratio will require correct metering using jets and rods...and since you are asking, it would appear you may not be well versed in carbology and yuo will need a carb guru...like Lars.


GL

Jim