new carb killing me HELP

[roudy4x4]

I just bought a new replacement carb for my 78 Malibu 305 Rochester 2BBL and I cant get it tuned at all. Ive read to keep the timing at 4deg. and to back the mixture screw out till the highest RPM is reached then leave it there... Well thats not working it either stalls, bogs, or has no balls... So how should I be tuning the carb, and where do you think i should put the timing?


THANKS

 

[85 Cutlass Brougham]

I just bought a new replacement carb for my 78 Malibu 305 Rochester 2BBL and I cant get it tuned at all. Ive read to keep the timing at 4deg. and to back the mixture screw out till the highest RPM is reached then leave it there... Well thats not working it either stalls, bogs, or has no balls... So how should I be tuning the carb, and where do you think i should put the timing?


THANKS

First off, you need to set the initial timing with the vacuum advance hose disconnected from the distributor and plugged. Next, you need to set the mixture screws-both of them. Start out with the car off. Now, turn both screws in until they bottom. Next, back them out 1.5 turns. This is your base setting. Now you can start the car. Try turning one screw in about 1/4 turn and observe what happens to the idle speed. If it goes up, turn the other out 1/4 turn. If it stays the same, turn it in 1/4 turn to return to base, then turn it in 1/4 turn again to change from base. You will have to keep doing this until you reach the highest idle speed, then set the idle speed where it is supposed to be. You may need to up the idle speed initially to get it to run well enough to do the setup and change it down as you get close. Remember to use a vacuum gauge to zero in on the final tune. Tune for maximum vacuum and you should get the optimum fuel efficiency and idle quality.Oh, and one more thing, you will need to reset the initial timing when you are done as it will change a little with the idle speed changes, especially if you can't get the right base idle speed when you set it. Just remember to finalize everything one final time when setting it up. It also would not be a bad idea to replace the advance weight bushings in the HEI distributor before you start so that you can be sure it has a linear advance curve and is not sticking. A sticking advance mechanism can ruin your day, so be sure it moves freely.