Dual Weber 40 IDF Quick Fix
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- Опубліковано 25 сер 2024
- Part #2 of my Weber Carburetor series. We will look at a typical used 70's swap meet 40 IDF carb. We take it apart and explain all the circuits, passages and options so you can set this carb up to work properly. I do not own a Ultrasonic parts cleaner but that would sure be nice.
I watched this over 4 or 5 sit downs. You took us to school. Thank you for taking the time, and simplifying these beasts. I truly enjoyed the education, and know it will help me with my 2 Weber 40 IDFs and 1974 VW Campmobile.
I hope you do it right and get many smiles to the miles like I have.
Very good job explaining to function on the carburetor here, and helping understand how they work... nice work!
Glad you liked it!
@@TheEZGZz
I have 6 of these on a Jaguar v12. It’s been many years of work on the engine. In order to confirm fuel level I modified the carb lid to allow movement of the fuel needle seat. This allows fuel adjustments without pulling the lid. The fuel level is measured with a tiny cork float and thin wire about 1 1/2” long. This is dropped into one well of the main jets and seat is adjusted as the engine is running on idle. Added oxy sensors on each exhaust bank and monitored with fuel/air gages. Otherwise impossible to balance the 12 throats.
If I remember correctly - a GM training coarse I took years ago. When they 1st put computer controls/sensors on carburetors.
The perfect mix was 14.7 to 1 ratio.
Excellent work -
I really appreciate all the videos you have done, they have really helped me a lot, thank you so much
Glad you like them!
Great point about re-labeling the jets. I have been guilty of that and it will really bite you later on different motors or trying to tune for different situations. B careful, we need you to be safe and healthy so you can keep posting these great vids.
Yep. I thought I had a pair of 135's but were really drilled to 145. Wasted a lot of time on that mistake.
You are discussing a very important topic. Do not be in a hurry. If the young people understood the information you are helping us with, they would watch this video 10 times and start to get it. The reason carburetors are the best for the individual, is that it is that you are in control. There is no place in an automobile for software. Thank you for understanding the importance of this topic.
You make a very good point sir! I will make that point in a upcoming video.
Thanks GZ, about time some one explains these Webers. I have one that is stuck and needs to be rebuilt. I asked many shops to rebuild, and they suggest buying new ones because its going to cost about a $100 less then new ones. In addition to this awesome video, can u do a complete tear down and rebuild. Thanks in advance.
Holy molly... Great stuff as always thank you very much master.
I hope you will get better soon, stay safe and healthy.
I can't wait to see new video.
Muchas gracias chief 👍
So on a a 5 Burrito rating your giving me a 5 ? whooo hooo
This is some great information. Wished I had known this when I was fighting my Webers a few year ago.
Thanks for sharing your wisdom. You've given me crucial context which really helps my confidence when I tear into my own VW.
Thank you for the support Matt
Awesome video EZGZ ,yes it's complicated but a hell of a lot easier than making sense of the drawings 😃😃
Thanks ez can't get these Italian 40 idf's to run properly yet on my 2276 rail. I'm breaking them down again to look for a gremlin and this is sure to help!
Clean, Clean, Clean. They should work good but they must work together.
great video I'm a old guy like you and appreciate all you do
I appreciate that
Thanks for the Video. It’s been keeping me motivated to put my Bug Back together. I bought a center carb set up that a guy had problems getting it to work. It uses a Dellorto DRLA 40. I paid $35 for carb and intake. Hope I can make it work on my 1641 with stock cam and 041 heads. Guy I bought it from didn’t use the heat riser tubes and fought intake frosting so I will be drilling my exhaust and using the heat risers.
Use a burr instead of drill. Go from both sides and try and force it in on #4 and blend it down stream on #2 it will help but barley works in cool weather. Getting warmer air to the air cleaner will help. Be creative with your testing.
Great video ! Keep up the great job!
Man I could've used this back when I had the 1600 in my Baja.
Lots of good carb info in here.
Thanks Mike. Be Safe
Grateful to find someone who is knowledge about not only Weber Carburetors, but carburrtion in general !
I have a VW 2200cc Dual Weber set-up, and had always thought I had a jet issue.
But now, I am finding out that there is more to it !
My high end performance is great !
But at idle, I am getting a periodic popping.
My left tailpipe is carboned, and obviously running very rich.
I am paralyzed from my neck down, and dependent on having help with any work on my carbs, so I have to be as knowledgeable as possible.
Hoping for input please.
Popping and snapping is a lean condition. Restriction in the jet, accelerator pump, ignition, vacum leak. spark plug, plug wires. No easy quick answer because I'm not there and you just have to go threw the search. It wasn't there before so something has changed????
@@TheEZGZ
Definitely not ignition related.
Over rich situation for sure.
Fouling the left side plugs, and left side tailpipe carboned up.
Totally understand you having not been here to evaluate the issue completely.
I appreciate your input.
Thank you for your reply !
@@quadsman11Well let's see. Bad Float, bad inlet vlave at the float fuel inlet, float level set to high, to much fuel pressure. Should be between 2 and 3 pounds. 3.5 absolute max. Let me know what you find and we will continue from there.
@@TheEZGZ
Thanks again !
This was a brand new engine, with brand new dual Webers on it.
Has always been running this way from day one.
Only on the left side, extremely rich.
Will check the recommended suggestions from you.
Again, I appreciate your help !
I'm about to put a set of cheap Chinese 40 IDF clones on a 1760cc, so this video came at just the right time!
Good Luck with your project. HEAT that manifold or you will hate the way it runs
ezgz you cant go until you at least have finished the weber stuff, built a super charged type 1 and done the spark plug lead things....thanks your work keeps us all going..
and your support keeps me posting.,,,,,,:-)
Great video! I have learned so much from your videos, thank you. I saw jbugs has a fuel pump controller for the electric fuel pumps which I think is a good and easy safety feature.
Cool ! I'll check it out :-)
👌 thank you for the vid
Pretty much the exact carb i plan to use
I hope you get as many smiles to the miles as I do........ :-)
@@TheEZGZ me too ! Thanks
@@TheEZGZ hello, I would like to ask about my particular set up, I really hope you can help.
I have a 2.2l Chevy ecotec 4cylinder engine on my desert buggy and I have one brand new weber 44idf carburetor paired up to it.
I have the carb bench set, 1.5 turns out on the idle mixture screw and 1/2 turn in on the idle speed, float level is 10mm.
I started the engine and it runs, I let the engine run for a few minutes shut it off and went to start it again and got nothing... i checked my plugs and they were black just carboned up.. I cleaned the plugs and it started again...
I wanted to get some input from you as I can see you are very knowledgeable.
Super Informative Video.👍. Like the background behind you. Thanks for sharing what you’ve learned over the years of working on VW’s. Good series. Take Care and I hope you’re getting better. BigW:-)
I found the right pill hehehe I will still be here to annoy everyone....
Really great video EZ - many thanks!
I appreciate your support
Soaking, or filling the bowl with CLR will clean out that white scale in the bottom of the carb. Leave it in only as long as needed to breakdown the deposits. Then rinse with hot water.
Thank You Sir! I'll have to give it a try.
Great video 👍
Thank you sir!
Great video lots of good information!
Glad it was helpful!
I'm a 40 year vw enthusiast. Have had shops in different states. And I really enjoy watching your videos. Cut from same cloth buddy.
Thanks for good info.
I actually have the Empi 2barrel that i had to correct float level out of box and change idle ,main& Air jets for my 1641 factory had float level so screwed up.
✌
It's not there job to tune it. They just supply the parts. That's why I make these vids. Glad you found it helpful
That was fabulous video!!!!! I am running dual Weber IDF's on my 1776 tub buggy, they work great, so far!!!! Thanks for the info and keep up the good work!!!!! Love that back drop. Where does some one find one those banners?????
The only duals I ran so far was the dual Weber 34s. I never went bigger yet. Great now I want a burrito! 🌯
Very good video EZGZ! I will take this corona time and will make a video of my 1500 with a sngle weber to show how its running. Hehehe
I would like that very much. Along with all the details, details, details. Please
@@TheEZGZ I made it :D Take a look.
There is eng subs.
Wow Im impressed with all that info ..having a bit issues with a new bug I acquired with 1600 dp with idf40 where I have no knowledge of the set up internally ..car runs ok and I can smell some gas in oil ....I'm assuming running rich
Single? Dual? Check fuel pressure. Add a fuel regulator if it's over 3psi. Stock fuel pumps can rupture and drip fuel directly into the crankcase. Carb has a fuel inlet valve could be leaking by. Float level to high. Other than that it should be ok.
Thanks for your good information👍🏻
Thanks for your support.
Thanks for explaining the details.
Glad it was helpful!
Great info EZ!!
Danger Will Robinson: Information overload LOL
@@TheEZGZ lol... it was a hottttt of info brother but loved it!
@@JWClassicVW Best to absorb with a brew. LOL
@@TheEZGZ you know it buddy
Thanks!
Great info. A buddy of mine had a cheap Chinese IDF 40 he bought as a back up and gave it to me. He never mounted it to his bug. I thought it would be cool to make a manifold and hang it off the side of my Yamaha xv750. What type of jetting would I be looking at, or what manual do you recommend to help me out.
Most of the time the carb comes with the proper jets to handle the air flow threw the venturi. That carb is to big for the displacement of your engine. You might get to run if you only use 1/2 of the carb.
IMHO if you just want to look at it or use it for 1/4 mile drag racing that one thing. But if you want to use it for normal transportation it ain't going to happen. Google Amazon to find a Weber manual or go the RedlineWeber.com
Hello, and thanks from Hessen in Germany. Good get know that for Aircooled with Weber.
Good to hear from the VW Motherland :-)
Awesome! I recently purchased a set of IDF 40’s for my wife’s 72 super. You mentioned a kit that moves the clock spring to the front side of the drivers carb to prevent torsion on the throttle bar bearings. Looking at the casting there doesn’t seem to be a hole for the spring end to lock in place, like there is in the back. How do you hold the spring in place?
Sorry but don't remember. It's been a while. Seems like it must not have been to hard or I would have remembered it.
Have a weber sidedraft with a turbo only seems to run its best at 3 and a quarter turn on the airscrew
Wish you would post some video on that. I love the side draft but again your asking 1 dual throat to feed 4 cylinders so of course your going to go more fuel on everything.
Ezzy are the choke cover plates suppose to have gaskets, I believe they should, I pick up some new Webbers and
was filling up the carbs with the electric fuel pump
one carb started filling the other did nothing , and the one filling up started to leek gas <
There are no gaskets on the choke block off plates . so should their be gaskets ?
thanks for looing for your reply ,
Cheers from the north !
No gasket. Sounds like you need to take things apart and inspect your fuel inlet valve and make sure the float level is right. Top of the float level with the base. No more than 3 PSI fuel pressure
Very helpful!
Glad you think so!
Good job great video
I just keep stumbling along trying to help. I appreciate the support
Nice job
Thanks!
I want to use a clone with isolated runner center manifold. Do you have any experience with this? Tight budget. Does the shorter manifold cause any cable issues?
Aint gong to ahppeh.. Been their done that.
Dam now i need a burrito
:-)
Hay ezgz is the new remanufactured 36 dellortors good thanks buddy .Harry
They sound good on paper.... I don't have any experience with them though.
I have a 1980 toyota corolla with these carburetors and for some reason the car revs without doing anything... any tips?
Float level and fuel pressure should be below 3.5. Not enough info to make further comments
I would appreciate your advice on this, I have a Type 4 2056 with new dual Weber 40's it runs great but my fuel economy is dismal at 12.4 MPG. I am currently running this set up Mains 140 Air's 220 EM's F7 IDL's 70 float height 11mm. Is there something obvious that should be changed to improve the MPG? Ignition is a 123 Dist.
Thanks
If you want better economy try the original factory setting and jet size. You may need to go up to a 55 idle jet.
Allso if your driving a bus. It is heavier and geared lower than a sedan.
WEBER 40 IDF Factory
Carb Dual
AIR CORRECTION 2.00
EMULSION TUBE F-11
MAIN JET 1.15
PUMP JET .50 .50
IDLE JET .50 55 (d)
VENTURII 28mm
@@TheEZGZ Thanks it is actually in a Porsche 914
Sir, I just got a set of Italian Weber 40s, what jet sizes would you recommend for a stock 1600DP at 5500 feet? I'm about an hour south of you. I've got 50 and 45 idles I can use, 115 main, 200 air, and F11 tubes, thanks. They were originally jetted for a larger motor at ~2200 feet. Also curious how far I need to break them down before I can put them in the dip. Do I need to pull the plate shafts? I've got everything out except for one venturi and the needles so far.
WEBER 40 IDF Factory
Sizes Single
Carb Dual
Carbs
AIR CORRECTION 2.00 1.60 2.00
EMULSION TUBE F-11
MAIN JET 1.15 1.45 (d) 1.15
PUMP JET .50 .50 † .50
IDLE JET .50 .65 .55 (d)
VENTURII 28m
Hay ezgz I’m having trouble deciding on the hpmx and the other empi duel single , what would you suggest thanks buddy
The only singles I like are the Kadron Solex Check out Jeff at the Kaddy schack
@@TheEZGZ thank you
Great video, long but loved every minute. I have two of these 40 IDF 82 on a VW bus but the whole engine flooded to the point of not even been able to crank the engine. Do these carbs not have an overflow? can one be fitted? Anyone have an exploded view with named parts for them?
The overflow would be at the top of the carb and allow it all to go in the engine. Your fuel inlet pressure should be less than 3 PSI and the float valve should hold that if your float level is correct.
EZ I want to buy a new 40 IDF. However I don't want a knock off Chinese carb. Where do you suggest. Thanks!
first off you want a pair of dual throat Weber 40 IDF carbs with 28 venturi's .
Don't even consider anything else. You will love me when it's running good and you will hate me when a problem crops up. Everyone who sells new weber carbs get them from the same distributor www.redlineweber.com/
Don't by anything used unless they are currently on an engine and you can drive it and it run's perfect like mine.
Next choice would be dual single 40 Solex Kadrons with 28 mm venturi
Follow the factory choice. They never made a car with centermount two barrel for good reasons. They used dual singles for space reasons, power and economy.
The CB performance weblink kit for IDF Weber carburetors is NLA from CB.🙁
It's there www.cbperformance.com/Weber-Carbs-s/152.htm#WJC
Should've watched your video before buying 2 sets of Webers! You went over things I'd wondered before, e.g. "are older engines / carbs able to respond to sudden throttle inputs".
Mine do just fine.
@@TheEZGZ Thanks for confirming! Turns out my timing was way off (3 degrees retard at idle)... I followed the "set correct advance at 3000rpm" rule most Porsche folks use (this is a 1720cc 912) and I didn't check the idle timing after that. Accelerator pump dialed in with the wrong idle timing works well with proper idle timing. But now there is a very noticeable miss / stumble under load which I suspect is the "Hot Spark" electronic ignition module I installed, will re-try with points. I hope it's not too much advance causing the missing, will re-check 3000rpm timing tomorrow when it won't be too loud / upset the neighbors.
👍 Great info.
your pretty great as well......
Hey easy I have a Weber 44 carburetor on my sand rail and idles fine everything works fine on it except as you talked about the hesitation when you 1st give it the throttle Would a good cleaning and carburetor kit Help this problem I have not always had this problem so I think something has changed in the carburetor mind you I'm quite a novice on carburetors and I hope I'm explaining it good enough for you I did just put new spark Plugs and I got rid of the points and have an electronic Distributor I'm a little bit scared of taking the carburetor apart also I do have a kit to put in it
Don't be scared. It worked before and it doesn't now so something has changed, Figure it out. Gas? Float? Inlet valve? Fuel pressure? Ignition? Plugs? Something changed, figure it out. correct it. Be Happy! If the mountain was smooth nobody could climb it!
Still having a little trouble understanding when the carb switches from the idle circuit to the main circuit. Also still not quite sure what those little progression portholes are doing
Those progressive holes are what takes you from idle circuit to main circuit. When the butterfly opens you get a rush of air and you need lots of fuel to keep the fuel ratio correct.
hello I have 2 hpmx 44 carburetor on my dune buggy with a 2276 cc engine and I have a backfire problem when accelerating at low revs according to me it is you because of a bad air fuel mixture or a fire problem please enlighten me
What you describe is usually a lean condition. Check your accelerator pump squirter's and make sure all 4 are squirting the same amount. Check all your idle jets again just to make sure. Check each spark plug and look for problems. Even a vacuum leak can be hard to find.
@@TheEZGZ thank you for helping me and I found the problem it was the condenser on the foot of the distributor which was in trouble I changed and adjusted my jets and the problem is resolved it runs perfectly thank you ez gz
One other thing to check guys.....if it’s been running REALLY rich and now it misses.....you fouled the plugs.....at a minimum clean them or replace to ensure you found the correct issue. Cheers
Great Tip! You win a virtual Burrito!
Does the taller velocity stacks make any difference?
Your not going to notice a big difference driving around town but a little bit here and a bit there starts to add up.
@TheEZGZ cool thank Ez, love your vids. I have them on even when I'm playn in the garage. 😁
I noticed your accelerator pump looks a little different than mine. It looks like yours has two Springs on it maybe? Is that how it's supposed to be? Mine only has one spring.
?????? monitor you spark plugs and dial it in to your needs, Mine came with double. Why didn't yours?????
Why does the carb gargle and leak when you turn off the motor when on a engine mount?
The fuel inlet valve controlled by the float is leaking by. Could be to much fuel pressure too.
I hope you get better on the runny nose, I am really new to dual carbs, what you think of dual Kadron on a 1776?
Kadrons are a nice solex carb that will work fine on a daily driver. With kadrons you will struggle with the linkage. With any dual carb you struggle with the linkage even with the fuel injected throttle bodies.
Hay ez I have an opportunity to get a pair of 40 and or also 36 dellortos for my bug , it’s a 1600 at the moment but I’m wanting to increase the cubes please let me know on your thoughts thanks 😊
If you can afford it buy both. I love my 36 dells and many of the 40 parts are interchangeable with the 36. These carbs are hard to find parts for.
@@TheEZGZ ok thank you, yeah,would like to have both. the 40s are in a Carbie repair shop $1600 aus that has been serviced and the 36 $800 private sale may need attention,both are Carbies only no manifolds,probably go with the 36 . It’s not always easy to know where to draw the line when it comes to money.
The 36 IDF (or dellorto drla) were standard on many Alfa Romeo alfasud/sprint/33 models. Some of the guys racing those cars went for the 40 or 44 IDF or 45 DRLA when the rules allowed, especially for the ones running high rpm and high power output, but there was also a restricted class where we raced the 1500 with the 36 weber or dellorto.
What are your thoughts on duel Weber 34 ICT's? We got a roadster from a friend of my wife that has some motor issues. I know it needs new heads and topend parts, but it is also running quite rich with the 34's. A big problem is that there isn't anybody within 6hrs that does much VW air-cooled work.
I've run them and they worked ok. Check the fuel pressure and float level as I mentioned in this vid
@@TheEZGZ I know you're an hour later than I am, I'm surprised you're up so late 😁
I have twin weber 34 icts on a 1641cc twin port ant they run great . I bought a wideband kit to help tune them worth every penny
I have a 1776 with the 40hpmxs and a c35 can and I've had lean running conditions for a while and I'm gonna clean out and check the bowls and floats and everything. It has 52 idles and I'll go to 55 idle jets. Should I change any other jets or bypass screws for a 1776? Also set floats to 10mm closed. What should they be set to open? Most of m problem is if I open the throttle too much too early, not stomp the pedal but just trying to accelerate I hear that metallic sound like nails in the engine, someone said it was pinging when I do that. Also what should I time it to? Thx. Love your vids!
Those jets sound ok. Why do you think it's lean? Snapping and popping is a sign of lean condition. I think Pinging (detonation) is very likely. Use a timing light and make sure you not advancing past 32 degree's max. Try finding some higher octane race gas or 93 non ethanol. I used to use aviation fuel (100 low lead). Bring a container to a local small airport and tell them it is for a off highway go cart. They will not put it in a vehicle that runs on the street.
A 1776 with stock valve head usually needs at least a .040 spacer shim under each cylinder. Do not try putting it in a used head. EZGZ out!
@@TheEZGZ I think it's lean since my gas tank was crumby and that got into the carbs. I replaced the entire fuel system which helped out a ton but it ran rough again. I'm pretty sure whatever was in the gas was gunking up the idle jets and it stinks horrible out the exhaust. I also noticed the throttle shaft has play on the left carb. I can't tell in which way yet. It also has 40x35.5 valve heads
Hey, nice video and thanks. I have a question for you. I have a triple set weber IDF 40 on my BMW (VGS 320/6). Everything is rebuilt and clean. but idling keeps to high even with the throttlevalves closed. No vacuumleakage but when I look inside the body I see fuel comming/dripping from the acc.pump jet during idle. Can you help me? Greetings from the Netherlands.
I am assuming your drip is coming from one nozzle. In the bottom of the float bowl for that carburetor you will see a brass screw. There is a steel ball inside. Make sure it is loose and seals when you blow from the threaded side. There is also a brass screw on the top rim of the lower body. Remove that and use a magnet to remove the steel bar and another ball. Both of these items are check valves. Also double check your float level and inlet valve at the float. Also make sure your fuel pressure is less than 3PSI. Hope this helps
@@TheEZGZ , Thank you for the quick reply/ All three carbs are doing this at every cylinder during idle. The bottom brass screws are working fine (the steel ball). At the spray nozzles the screws that are inside do work fine. I have the system where the spray nozzle is mounted with a screw and two copper rings. Does that screw have the weight and steel ball inside then? The fuel pcv regulates at max 4 psi. The original carb worked fine with that.
Hey, quick update. The checkvalves in the floatchamber and the checkvalves in the jets are replaced by new ones. Floatlevel is checked and re-adjusted to the factory spec (10mm close and 32mm max open). The problem is still there at all three carbs. Do you have some info about the floatlevel in the carb? Idle is still to high with the throttlevalves closed. Vacuumleakage is not found around the carbs. Thanks for your input. Greetings from Holland.
@@323baurFuel pressure must be under 3 PSI
Standard IDF Settings:
Speed screw ¼ to ½ turn in after contact with lever maximum.
Mixture Screw 1 turn out from lightly seated.
“Lean Best Idle” Procedures
After confirming the linkage allows the throttle lever to seat against the Idle Speed Screw. Back off the Idle Speed Screw, then turn the screw in until it contacts the throttle lever and turn it in ½ turn. Turn in the Mixture Screw in until it “LIGHTLY” seats, then back it out 1 full turn. Loosen the 8mm wrench size nuts on the “air bleed” screws, turn in the air screws until it seats then tighten the nut.
a. Start the engine, it will run slow and like a tractor. As long as it will stay running, the idle speed is not important at this point.
b. First, turn in the mixture screw until the engine runs worse, then back out the screw ¼ turn at a time. The engine should start to smooth out. Continue to back the screw out ¼ turn at a time until the screw does nothing or runs worse. Then turn it back in to the point where it ran best. You want to tune the engine by sound. Adjust each mixture screw to the best, fastest and smoothest running point. Do this procedure with each mixture screw.
c. Now you may adjust the Idle Speed Screw. It should be sensitive and only require ¼ turn in or out to achieve the idle speed you like.
d. These carbs are commonly used in pairs, this makes the synchronization important, be sure to bring the high flowing carb down to the low flow carb. Then bring them both up to “proper” Idle speed. The Idle Speed Screws are not opened more than ½ turn in.
e. After synchronizing multiple carbs, reconfirm steps b. c. & d.
“Simple Rules for Calibration”
If your mixture screw is out more than one turn like 11/2 turns then your idle jet is too lean, go up one half size on the Idle jet.
If you mixture screw is not out one full turn, something like only 1/2 turn out from seated then your Idle jet is too rich, go down one half size on the idle jet.
This is all based on the important fact that your speed screws are not open more than ½ turn if they are then that is also an indication that you have a lean Idle circuit. You are cheating by opening the throttle plates and exposing additional progression holes in the transition.
Pump By-pass Valve:
The pump by-pass valve is designed to allow fuel into the pump circuit and when depressed, by-pass a percentage (hole on the side of the valve) of the fuel delivered to the accelerator pump nozzle/jets. We have included the zero by-pass valve in our jet kit. This will deliver all of the available fuel to the engine and not by-pass fuel back to the fuel bowl. This will increase the duration and volume of the pump shot with the original pump jets. To decrease the duration and increase the fuel volume we have included in our jet kit the larger 55 pump nozzle/jets. This is for maximum fuel delivery from the accelerator pump circuit. The accelerator pump by-pass valve is located in the bottom of the fuel bowl, one is required per carburetor.
More Tuning & Adjustment
1. Most Critical! Be sure for initial carburetor set up all air by-pass screws should be in closed position. These are not commonly used in standard carburetor adjustment.
2. Set the idle speed screw at ¼ to ½ turn in after contact with throttle lever. When doing multiple carburetors all linkage should be disconnected. All carbs should be bench adjusted to same setting.
3. Set the idle mixture screw to one turn out form lightly seated. When checking the seated position to make only light contact with seat, aggressive seating will damage needle and seat of carburetor,
Adjustment if possible should be to find smoothest idle with each mixture screw on all carburetors. Some prefer to do one barrel of each carburetor then come back and do the second barrel
4. Start engine as long as engine starts and runs do not turn up idle speed first.
5. After preliminary lean best setting of idle. Check carburetors for synchronization. Commonly done by checking lead or front barrel of each carburetor.
6. You will always want to bring high flow carburetor down to match the low flow carburetor. If this cannot be done you will need to recheck bench assembly for binding throttle in high flow carb. Once you have matched both carburetors you will need to set the idle to the desired idle speed setting. This will be done by adjusting both carbs up or down the same amount and re checking for synchronization.
7. Make one last check of lean best (smoothest running position) idle on all mixture screws one last time.
8. Best idle should end up with the mixture screws at or near one turn off seat. Check rule of thumb for idle jet selection on the other side of this page.
REDLINE
1225 W. Imperial Hwy Brea, CA 92821
1-877-405-4345
REDLINE is a division of WORLDPAC
Hello I got a question can you swap the pan a Super beetle to a 64 frame
Sorry, different animal :-(
We didn't have vents on our roof or water in the toilet bowl. Out house. No electricity and a pitcher pump.
Not sure how to post picture of my sidedraft i dont have a channel
Have you tried cb performance upgrade kit? Im looking to see if it will help tunning
Yes, the jet doctor is great. The spray bar is more for performance. It depends on the engine and what it's used for. If you have a stock 1600 it won't do a thing
@@TheEZGZ im running a 1835 with dual 40 idf looking at going with matched 44 and heads from mofoco any suggestions? I have a few videos of driving my rig
Have a question EZ, would it be possible if we can chat? Having some serious issues with my Dual IDF 40's and would love some pointers! Thanks!
How about you leave your question right here in the comments and I will try and answer it so that we can all share the problem and solution. Thx
@@TheEZGZ No problem!
The issue seems to be that it is breaking up at part throttle, 1/4 to 3/4 throttle it completely sounds like it's running lean. I pulled all four plugs and the right side is black as night and the left side doesn't even have carbon on them.
It's a 1776 with a 110 cam, at 4500 feet, my main jet is 115, idle is 55, and air is 180. The heads have been opened up a bit for a bit more airflow, but no serious porting.
I appreciate you uploading all this information, it has helped so much.. keep them coming!
Thanks again!
@@MrJiraiya171 I may have you covered in my newest video! Carb linkage is critical if one side leads the other it won't work right. If you move your gas peddle to WOT both carbs should end up on the full open stops if they don't your geometry is off.
Also you can not have your progression holes exposed at idle. You will have to remove the carbs from the car and remove the carb from both manifolds to check it. www.redlineweber.com/html/Tech/idf_adjustment_controls.htm
how do you clean the intake filter on those?
I made a short vid on that. You may want to search my videos. K&N makes a whole kit to recharge cotton filters. Most auto stores carry it. I'm cheap. I use simple green, let them dry and then K&N spray oil
@@TheEZGZ I have a unique car. It is a Brazilian made chevy with 4.1 liter engine that used a weber 40. The car was just shipped from Brazil to USA. It took 8 weeks in a ship exposed to the saltwater environment. I cannot start the car. If I put a small amount of gas in the venturee cylinders (as you described them), the car comes on for a few seconds then dies as soon as the small gas amount is used up. I checked the mechanical fuel pump, and it is pumping gas to the carb. Without taking the carb apart, I checked the small opening in the top (the one u stated is used for ventilation) and I can see some gas in the main bowl. My guess, there is an issue of gas transfer from the main bowl to the venture cylinders.
If I am wrong about seeing gas in the main bowl, then something is blocking the gas going inside the main bowl. You mentioned in this video, there is a filter inside the carb in the main gas inlet. Was asking you how you remove this filter. FYI, I am not a mechanic and have extremely limited abilities.
By the way, great video.
@@TheEZGZ I found out the problem. The valve for the float is getting stuck in the closed "up" position. Why would it stick? does it mean i have to replace the valve or i can just clean it.
did not open the carb. this is by putting a screw driver tip in the opening vent in top and pushing the float down
If the car sat without running for months on end the fuel dries out and can cause some sticky deposits. Sometimes just tapping on the bowl while cranking the engine will clear it and fresh gas will clean it. Better to just take it apart and use some spray carb and choke cleaner and put it back together with fresh gaskets and accelerator pump diaphragm. A clean and properly adjusted carb makes the car so much more fun to drive.
Good evening I have a central empi 40 idf in my 68 bug. You could help me with the correct measurements of air and gasoline in the jets. At the moment I have 150 in gasoline and 180 in air but the consumption is excessive and the engine heats up more than normal. I appreciate your help in AVANCE.
Those carbs on center mount suck on MPG. Should have gone duals but then the headache of when (somethings not right which jet is plugged??? I have many vids on that