This conversation comes up every now and again, but that's okay, I don't mind chiming in! The Riv gets about 12 city driving, 16 regular city/highway 17 highway and my record is 19.5 on a 3 hour highway cruise at 60 mph. The 2.93's really help for that! I'd fill up a couple times to full at the same station and work it each time and then take an average. As for warming up, you're choke may not be working, I run chokeless and my car is how you describe it until it warms up. Usually about 5 minutes. If you have the Buick manual it describes how to set the screws on the carb. 1/4 turn here and there is all it takes.
I actually have my choke dialed back almost as far as it will go, because it worsened the milage to a pretty much horrible level even when it was just a little bit rich. I literally used up a quarter tank of gas in a day of driving, adn I didn't drive all that much either. As for the carb screws... I'm guessing Buick got more on the ball for owners manuals in '71, because mine mentions nothing of the sort (It says "Owner's Guide" on it-different than the manual?) And, I'm going to shamefully admit right here and now, that I don't know what secondaries look like. I know what they do, and why they exist, and why them being stuck open would be bad... but still have no idea what they are. I'm 16... cut me a little slack? p ~Mike '66 Skylark 340-4
Hey Mike. I'm referring to the massive Buick Service Manual. As for the secondaries, They are the back openings on the carb. The bigger ones, closest to the windshield. All the carb adjustmenst are done by screws on the front and side of the carb, but first you have to figure out which screw does which. I would think that you're running rich, is there a lot of black smoke when you punch it? Any bog when you do?
