I used a vacuum gauge attached to the intake manifold when adjusting my fuel air mixture screws on the lower front of my motorcraft 2150 carburetor. Do NOT come off any port of the carburetor. Run both screws in until they slightly bottom out. Then open both @ 2 complete turns out. Next, start vehicle to warm up. Work only on one screw at a time. This takes patience. Turn screw in or out until you obtain the lowest vacuum on the gauge. Finally you adjust the other screw the same way. I was able to obtain 20 in vac on my 79 F150. My truck runs great. Remember that the environment temperature affects the adjustment of any carburetor. Plus the choke adjustment is done with the engine COLD.
Before you start, make sure your timing is good and all your vacuum hose are intact. A vacuum gage will help with the mixture quality screws. With the truck running and at operating temperature, adjust to highest vacuum at idle, which might raise your idle speed. Reset idle speed and recheck/readjust your idle mixture. it can be like a game of ping pong but you eventually get close. The choke spring (3-screws) probably needs to be done every time you have a major temperature change (summer/winter) and will effect mileage.
my 84 d150 has this very carb. and this video has been the absolute easiest to understand. I'm new to the give a fip about a vehicle. I have 96k original miles on a 318.
“i’m still not great with it because i’ve been messin with it twice and it still don’t run right” haha this is honestly exactly what I needed to hear makes me feel better
Your video has brought 3 days of pain to an end the way you explained it was the best i have seen yet. everyone was telling me that the idle adjuster screws were the ones that change the idle speed. as soon as i adjusted the screw may problems were over. thans again!
Thanks for taking the time to explain the way to create the proper air adjustment. The video could have been better, just less shakey, but the quality of your input was fabulous and easy to follow. It is definitely appreciated. With just a few tweeks of the screws on my 1978 Ford Bronco following your direction it is now running like a charm. I had been struggling with for the last four days until I turned to your RU-vid video for tutoring! Thanks again!
As I watch this again for the third time, and compare it to others I am glad you took the vacuum and air filter completely off. Good job on having enough light which most people don't. I think if you wrote down a general script, so you wouldn't do the ahhh and er thing it would help to. This is actually better every time I watch it!
Very nice instructional and lessons on adjusting carburetors Richard. Not many people know too much about them these days. Please keep up the tutorials you are giving.
The two screws on the bottom front are the Idle air mixture screws. Correct they are not for setting the idle speed. But, if you are running rich or anemic, you will have a hard time keeping the engine idle speed steady at varying temperatures. You can foul plugs if too rich, and burn valves if too lean.
Never thought of that before jack I bet it would but I don't have a vac spec for what it should be set around. What I have seen people use now is digital volt meters that have an rpm gauge built in it seems to work fine but they are very expensive to come by. Thanks for the comment Jack!
I would love to see you adjust the air/fuel screws with the truck running AND with those screwdrivers while you are watching your vacuum Gauge. everyone wants to show how its done without actually doing it.
Thanks brent I will have to check out that movie I kind of ignored it at my movie store but since you brought it up I will be sure to go and check it out.
lol electrical problems are always fun I have learned never to give a vehicle a fuse that wasn't called for that could be disasterous hopefully you get yours fixed soon.
lol thanks for the compliment I want to keep it somewhat stock in the motor department im not gonna get fancy just a little more cubic inch displacemnt under the hood and a better fuel delivery system. Heck even stock 390's with a good 4 bbl carb were pushing 300 hp thats great numbers for that time in my opinion. Looking forward to seeing yours as well thanka again!
Other then a few problems,I have never had them,Q-jet is a very decent unit.The 200-4R is off a 1989 full-size GM,it is being modified for more endurance,just to name a Kevlar band for the 2nd band position,improved pump,hardened pump rings, premium friction discs,all bushings renewed so clearances are correct.Shift kit,and a huge oil cooler to help keep the 2000 stall torque converter happy.I will get the lock-up working so I have the best of both worlds. The 200-4R behaved better then the 200.
Thanks Howie I feel the same way you do about this its becomming a lost art unfourtnatly so Im trying to learn as much as I can about them. I will try howie unfourtnatly I will lose my main character here in a couple of weeks when it goes in for a motor overhaul darn lol.
And now that I am done being a jerk. Thank you for taking the time to do this. I did tv commercials wrote em and filmed them, so I am unbearably critical. With that I think that with your knowledge and a tripod with an adjustable lens you could practice up and make good enough tutorials to sell them. So few people know how to take their old engines and tune them up to get the top fuel efficiency. I would really like to see a web site step off from here showing how to tune up 2v carbs, change manifolds, change heads out, to get the fuel efficiency that new cars get. Start here, and then step off to your own website. I know I can get up to 25 mpg out of my old 1981 F100 302 Windsor. Just by Changing my DuraSpark II to a GM HEI with some junkyard parts, getting rid of old oil filled coil, and do it for less than $50. Get a dual plan manifold and change to aluminum heads. Up the Horsepower and lower gas consumption. Please write me if you would like to collaborate???
@mitteey it really depends on how the motor will react to the adjustments and of course what a lot of people say altitude. I believe I had them both at about 31/2 turns to 4 turns out. A good base for it is after or during a carb rebuild is to turn them all the way in till they bottom out then back them of two full turns on both of them.
@mitteey its kind of hard to see these ones they set real low on the carburetor almost near the intake manifold but if you have a long screwdriver they are easy to get to. The refurbished edelbrock I put on this truck is easier to adjust because they are right in the center of the carb not underneath it near the manifold.
Your very welcome. Yes you are right the american cars have options and resources still avaliable to this day. Might I add their more fun to work on than the imports of this era or of the 72's era. I still don't know anyone around here that would rebuild and adjust a honda or toyota carb.
I got a 1979 F150 302 cubic inch V8 2 BBL carburetor and looking for a good picture of the correct location of all three springs on the diver's side of the carburetor. I replaced my old original one with a "bench tested" as they say Motorcraft 2150 carburetor. I would like to get her back on the road soon. Can you help?
There may be castings somewhere on you carb they vary different years but ford put metal id tags attatched to one of the screws on the upper portion of the carb for various years however I will say this if your just needing a carb kit they are pretty universal unless you get a later 70's early 80's one with emissions junk on it.
only video easy to understand i have come across so far. very similiar or same carb thats on my 83 jeep. needed to know if theres two adjust screws on front and there is. thanx
Well I guess the main charicter will be returning with with a nice set of muscles to show off! Your talent on carburetors will be a much appreciated one before too long. The Q-jet on my car seems to be just fine, so hands off for now! So far, so good on my project, the 200-4R transmission overhaul is coming along nicely.
Where's the "overcoming the vacuum leak" screw? lol A big thanks for the vid. In some way I want to bring my '72 back to original. For better or for worse, originality is a huge factor and something to be cherished. Even in small doses, whether it be carbs, wheels, or stereo. Nice ride, tx again-
My question is. This looks like what is on my 79 grand marquis.. there is a screw behind the choke adjuster. I have not been able to get it to do much as far as the choke goes either with that screw or the knob. Did find it helpful on the front screw
Thanks I act well don't I lol. I have some basic knowledge of it Im no master however by any means trust me I made the error of getting myself stranded by fouling plugs it sucked so its a learning experience thats what I love about automotive technology.
I have a Motorcraft 4bbl on a 460, when the motor is cold, choke is cold it idles smooth as silk but when its warm and the choke is fully open it idles rough and sputters. Drives perfectly fine though. Would that mean the choke needs adjustment?
You did not mention how many turns on the screws,this would give all of us a starting point when trying to adjust the carburetors,,Do you remember what they were????
Hey! I have a 71 F100 with a 302 2V. It was running when I tore the beast apart. I have now put the engine back in, and I need some insight on how to hook up all the vacuum lines, gas lines, etc............... M
Moter craft 2 barrel carburetor 351 Cleveland how do I set carburetor with electronic choke on the carburetor ever things rt now new on car 72 mustang fastback 351ç
Thanks for the video I need some advice I just messed with the fuel mixture on my 2 bbl edelbroke I thought I fixed my excess fuel smell which I did but now my idle gets stuck so high fast that the cars keeps on going even after I released the gas pedal... Any advice will help??? Thanks
+TheGSummit Lol, there is a screw that holds the throttle open just a small amount. That is your idle speed screw. Back it out until you find the proper idle.
Man I have the same carburetor and the idle speed screw has to be in the middle if I go up or down it will idle stupid high. Why is that? I'm getting tired of idling at 1250 rpm every time in park
Darn howie I have always wanted to play with a Q-Jet lol. Thats cool howie is this 200-4R stock or off a late model car because if I remember right gm had the 200 as the lowest transmission I think behind the 350 and 400's?
Well what shape is the carb in has it been rebuilt? it should idle a little high until the choke comes off if its too high try adjusting the choke and see if it slows if not let it warm up and try to only notch it down little by little. I ask if its rebuilt because one of the circuits in the carb might not be right and need cleaning or cause a hang up in the carb
Hey, thanks for the vid. I have a question for you. I a motorcraft carb with electric choke. My truck used to have the kind of choke yours has. Well my problem is that my choke butterfly flap is stuck just barely open. I've hooked up 12v dc to the choke but nothing happens and the truck dies when it gets warm. Any ideas why? It's a re-manufactured carb so it should be working right.
I was wondering if the max speed I can get on my van is 65MPH. what adj will I need to do to the carb if everything else is good and my last option is the carb. The van supposed to be able to go at lease 80MPH or more max.
I have a 352 FE with an autolite 2100 2bbl on it. I'm not having any running issues, just consuming a lot of fuel and my plugs are black and soaked in fuel. how do I correct this issue?
what are some things thatvwill cause my accelerator pump to not work, i just rebuilt the carb on my highboy and it stumbles like hell on take off any pointers
Hi have this same carburetor and im having issues with it do you perhaps know where i can get schematics for it, im sure something is broken on the exhaust manifold heated choke system so some broken pieces but i dont know what exactly its supposed to look like
How is working with the new edelbrock?? im kinda tired of this carburetor! im honest! it just doesnt run right! im thinking in an edelbrock 500cfm 1404!!
I have a 73 f100 with a 360 it has this exact carb. It's stuck on high idle, hard shift doesn't kick down when warmed up. What do I adjust to make that happen?
Hey, Richard! Great vid! I think that's what my 72 'Stang has..2 barrel, and the choke adjustment is the same. Would a vacuum gauge be helpful for the best idle? :) Jack
Please hold camera still, and don't spend half your time selling a found screwdriver. I am sorry you don't have a tripod but do you have a friend that doesn't have shaky hands?
cool video looks like you know what your doing, i suck with carbs myself i messed with my carb on my dirtbike for about a month and finally i just blew out the seals and had to replace all of them also i love your truck!!!
ya i know my dads 2002 f250 has some major problem and keeps blowing fuses and man we just keep getting stuck and having to rig it right there to get home
