There are really only 2 screws that you may need to adjust and both of them deal with the cars idle quality. One screw is just for idle speed and turning it in increases the idle and turning it out decreases idle. Simple enough. The other screw is for idle mixture and it should be under a plastic cap (which may have been tossed at sometime). The plastic cap limits the amount of adjustment so people wouldn't screw around to much with the mixture and cause pollution. If the cap is on the screw pull it off to make the adjustment and pop it back on when finished. If the cap is missing there will be a new one in your carb rebuild kit. Your rebuild kit will have a chart and give you a bench setting for the mixture screw, something like 2 1/2 turns out from seated position. Never use a screw driver to seat the needle, hand tighten gently with your fingers only and then back out to the bench setting. To adjust the mixture screw - CAR MUST BE FULLY WARMED UP AND CHOKE 100% OPEN. You don't need any tools other than a screw driver here. With the car idling at the lowest possible point it can and still run smooth, turn in the mixture screw very slowly. You will here the engine RPM increase as the mixture leans out. When the RPM falls off and the car begins to run rough back out the screw 1/2 to 3/4 of a turn and snap the plastic cap onto the screw so the adjustment stop is centered in the rotation travel. Now set the idle speed to factory specs - like around 600 RPM (check your book for actual RPM) That is pretty much it for adjustments that you should be doing. There may be a dashpot to adjust - see a book on how to do that.
I use a tachometer to adjust the mixture - My ears are not sensitive enough to do the job. I watch the tach for the RPM and the stability.
I like using my ear. I've got a good feel for it. Before cats, we used to use the exhaust gas analyzer to set the mixture ........ 16:1 ratio was tuned if I remember right. That's along time ago. There is a sniffer on my tune up machine but I haven't used it in years.
If anyone is interested, here is a list of Walker brand carb kits for stock Ford, Maverick and Comet applications. I buy mine at O'Reilly Auto Listed by year, engine, carb model, and kit number. 70-74 170-200 YF 15447B 70-74 250 RBS 15475 70-71 302 2300 15129 70-74 302 2100 15369D 75-77 all 6 cyl YFA 15681A 75-76 302 2300C 159048 77 302 2150 15677A 77 302 2700VV 15680A Please make sure you know what carb you have before using this list. Don't just go by year and engine size as your carb may have been swapped over the years.
Just noticed something that I am sure is really really bad.... Car is not only running rough but its spitting black smoke and I think a drop of oil just came out of the exhaust....What do I do to examine and fix this issue?
Black is excess fuel, either from being too rich or a mis-firing engine. I'd get that carb issue taken care of, put in a fresh set of spark plugs and make sure timing and the rest of the ignition system is set properly. If there is no mechanic isses with the motor, that should take care of your rough smoking engine problem. What you think is a drop of oil is probably just sooty condensation from the rich exhaust. My guess: Fix the carb problem and tune it up ...........
Alright I will definately start there... All of your info and input is greatly appreciated...I am going to get that rebuild kit soon after I get off work and put in atleast an hour and half before I go to school tonight... How do you set timing?
Is there someone in your neighborhood or a friend from school that works on cars? If so, ask them for some help. You will need a timing light and a couple basic hand tools. Rebuilding a carb, while fairly easy, does require some skill to get it right, and some help from a friend that knows what they are doing is what will be best for you. If you do want to tackle it all by yourself - you must first read how to do it - Chiltons book will cover this. If you don't have a book - buy one and read it first. Having a manual to do even the most basic repairs will save you time and a ton of money in the long run. If you plan on doing more advance work on your car - invest in the Ford shop manuals - a 5 book set is about $50-60 and is the same manuals mechanics use. Here are a couple Chiltons on ebay http://cgi.ebay.com/ebaymotors/CHIL...60225067904QQptZMotorsQ5fManualsQ5fLiterature Buy it now - with shipping less than $20 http://cgi.ebay.com/ebaymotors/MAVE...90382964049QQptZMotorsQ5fManualsQ5fLiterature ************************************************* When you get your carb kit - it will come with some very detailed instructions too. Just watch out, as there are several small parts inside a carb, like check balls, needle valves and tiny parts. All need to go back in the right place, and this is where a novice can get lost real fast. I usually spread out an old bed sheet to catch all the little parts. The check balls are the worst, for loosing them is quite easy to do...... Here are a couple pictures of what the instruction sheet looks like - THIS IS NOT THE RIGHT ONE FOR YOUR CARB (but it is close so it will give you an idea of what is inside of a Carter YFA)
Look what I found on ebay .......... $50 for a rebuilt (by Holley) Carter YFA .... http://cgi.ebay.com/ebaymotors/Reco...ptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories I think this is a great option for you to solve your carb issues ... as much as I like rebuilding them .... $50 is a good deal!
