The method I was taught and have always used when adjusting a multi-barrel carburetor is to adjust one screw until the highest vacumn is obtained, then adjust the second screw until highest vacumn and leave it. My question is, will this work on a single plane intake like on a slant or is a different method used? I've only ever done this method on v8's with dual plane manifold.


Thanks
Kevin


PS, my carb experience is limited, as I'm only 31, and have never had to work on them on a regular basis. I'm a mechanic by profession, but carbs have gone the way of the dinosaur.

_________________
crossthreads are better than locktite

Both screws need to be adjusted the same number of turns out from seat. Carburetor operation and repair manuals and links to training movies and carb repair/modification threads are posted here for free download.

_________________
一期一会
Too many people who were born on third base actually believe they've hit a triple.

if you want to be on the lean side adj screws in the same until you notice a stumble or drop in rpm then turn screws 1/4 turn out, if you want on the rich side do the opposite, it is harder to feel the stumble on the rich side, you might have to repeat a few times to get it right.

Thanks for the info Dan, I'll give that a try. A decade ago when I was in college for auto mechanics we did do a semester on rebuilding and tuning carbs, It's funny, nobody ever mentioned using a tach or keeping the screws in sync. I was taught to use a four gas analyzer and if that wasn't available to use the vacumn gauge method mentioned earlier. I actually looked up my school notes on this, and the only mention of keeping the screws synced was this "When done, mixture screws should be within one turn of each other, if not, engine has a mechanical problem". The professor was a ASE certified master tech with like 30 years experience so I always assumed he knew his stuff :shrug:

Kevin

_________________
crossthreads are better than locktite

the screw might be off a bit from each other but not a full turn.

Oh, forgot to mention, the 2 barrel in question is an Autolite 2100, not the more common Carter paperweight

Kevin

_________________
crossthreads are better than locktite