Carb, Jet sizes
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From: Concord, New Hampshire
Carb, Jet sizes
Ok, i know this is sorta the wrong forum, but i was unseccesful in getting any answers in the right forum so im hoping some people with slightly older trucks can help me, I have an 87 f-150 4x4 auto, 351w with a 4bbl carb, im wondering what are the jet sizes supposed to be and where would i find them, i think the previous owner may have changed them becuase the truck likes to idle rough, like its flooding itself over, any help would be gratly appreciated.
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ok, when you say float adjustment, should the level be set so the gas just barely flows out the screw holes? or should it be somewhere within there, the weirdest part of all this is i took off the carb, to put on another wich unfortunatly didnt fit because someone bodged up the throttle cable hook up to fit something else, but when i put mine back on after turning it upside down and all around and whatknot, it seems to run much better, but i think im gonna still rebuild it,
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ok thats what i thought about the power valve, do you know if the rebuild kit comes with blowout protection for the powervalve? and thanks so much for the help, the 87-96 forum was none at all,
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If you have a Holley carb you should get a new power valve to install.
If it's a stock Ford 4V it is most likely a Motorcraft or a Autolite. Thoes kits also come with power valve.
You should be able to get the number tag off the carb by removing one of the float bowl screws. Take the number tag to the parts store and see what rebuild lits are available. (If it's a Holley, you'll have to copy number off carb body)
Good luck.
If it's a stock Ford 4V it is most likely a Motorcraft or a Autolite. Thoes kits also come with power valve.
You should be able to get the number tag off the carb by removing one of the float bowl screws. Take the number tag to the parts store and see what rebuild lits are available. (If it's a Holley, you'll have to copy number off carb body)
Good luck.
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No the rebuild kit will not have the blow out protection retrofit kit. You will need to get that separately. The rebuild kit should have the two stage power valve which you will need. Make sure it is the two stage type and not the more common single stage as used in cars.
Good luck,
Mark
Good luck,
Mark
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From: Concord, New Hampshire
ok, and should i bother with the blow out thing? and has anyone done this before, ive never done a truck carb, dirtbike snowmobiles motorcyles, thats all with me but will i need special tools or anything, and when i get the kit will it have just the right size jets or many diffrent size jets, and if it does how do i know which ones are right, sorry about the questions but thanks.
oh and yes its a motorcraft, i have the numbers off the tag, so will the powervlve come with this kit as well, and how do i tell if its to stage or not,
oh and yes its a motorcraft, i have the numbers off the tag, so will the powervlve come with this kit as well, and how do i tell if its to stage or not,
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Although it says Motorcraft I think Ford was using Holley carbs at that time. The rebuild kit, no matter which make it is for, will include the power valve. If it is a Holley you can tell which power valve it is by the number stamped on it. Holley has them listed on their web site. Plus, assuming your carb has not been tampered with then it should have the same numbers as the power valve in the carb now.
The rebuild kit probably will not have jets. They are “hard” items and can be cleaned. Jet sizes are stamped on the side. Jets should not have to be replaced, just soaked in carb cleaner.
Installing the blow out protection is obviously a good idea since Holley has made it standard issue on new carbs and if yours is in fact blown then it clearly could blow again.
Personally, I wouldn’t waste my time with that carb but would get a remanufactured Edelbrock and be done with it. Once they are dialed in they will give you much less hassle than the Holley, especially the Holley 4180’s used by Ford during that era.
Good luck,
Mark
The rebuild kit probably will not have jets. They are “hard” items and can be cleaned. Jet sizes are stamped on the side. Jets should not have to be replaced, just soaked in carb cleaner.
Installing the blow out protection is obviously a good idea since Holley has made it standard issue on new carbs and if yours is in fact blown then it clearly could blow again.
Personally, I wouldn’t waste my time with that carb but would get a remanufactured Edelbrock and be done with it. Once they are dialed in they will give you much less hassle than the Holley, especially the Holley 4180’s used by Ford during that era.
Good luck,
Mark
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well im strapped for cash right now, i have my chances to get a holley 600, right now for cheap, would this be a good investment? i also have what i belive is a holley 750 that mu cousin gave me off his 79 f-250, wich had a 351 or a 400 i cant remeber now, im thinking about getting the holley 600. but there are two ventlines that come off the bowls of mine and neither of the carbs i can get/have have theese, whats up with that?
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I’d be careful with used carbs unless you know for sure that it is a good operating carb. A stock 351 would be over carbed with a 750. In fact, a 600 is a little on the big side. Too much is not just right in the case of carbs. And with it being stock and having EGR and such the carb will need to be an emissions type unit. Compare the price of a high quality rebuild kit (not your local parts store name brand kit) and the cost of the blow out protection kit to a Edelbrock remanufactured unit. I got mine for less than $200.
BTW, you have confirmed that you have a Holley with your comment that you have two vent tubes coming off the bowls.
Good luck,
Mark
BTW, you have confirmed that you have a Holley with your comment that you have two vent tubes coming off the bowls.
Good luck,
Mark
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yeah it looks just like the 750 but a bit smaller, and what are the vent tubes for? the two 750's i have dont have them and neither does this 600 (i think) i was gonna buy, its on an old cj-7 jeep but its an offroad 600, its old but doesent have even a tank of gas on it, and has all the floats and tubes for off road with it, im gonna find out how much my boss wants because if its cheap and will fit im gonna get it, i need something and im getting desprate, pluss the off road will be nice, when i park at steep angles, my truck floods over, and i park at angles all the time, gotta climb the nearest snow pile/ dirt pile or anything cool to park on at school.
And can i plug the lines on the truck if i swithch to a diffrent carb without them? oh and the egr, it has an airline to if from the airpump, the line is disconnected ie, no air, but that shouldent make a diffrence with flooding over. right?
And can i plug the lines on the truck if i swithch to a diffrent carb without them? oh and the egr, it has an airline to if from the airpump, the line is disconnected ie, no air, but that shouldent make a diffrence with flooding over. right?
Last edited by ATC_250SX; Mar 24, 2004 at 11:36 AM.
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The vents are for pulling fuel vapor out of the bowls and through the charcoal canisters. That system also pulls the vapors from the fuel tank.
A non-emissions carb will run rich, maybe even very rich, on your motor. You will have to change out jets until you get the air/fuel mixture right and on a Holley that means removing the fuel bowls and spilling gas everywhere each time. If you installed an emissions Edelbrock it would be much closer to the correct jetting out of the box and changing out the jets and metering rods is very easy without spilling a drop of gas. Any carb is going to need to be dialed in to the specific engine; it is a lot easier with an Edelbrock. They give a detailed step by step procedure in the owner’s manual on getting the carb set up and dialed in.
Good luck,
Mark
A non-emissions carb will run rich, maybe even very rich, on your motor. You will have to change out jets until you get the air/fuel mixture right and on a Holley that means removing the fuel bowls and spilling gas everywhere each time. If you installed an emissions Edelbrock it would be much closer to the correct jetting out of the box and changing out the jets and metering rods is very easy without spilling a drop of gas. Any carb is going to need to be dialed in to the specific engine; it is a lot easier with an Edelbrock. They give a detailed step by step procedure in the owner’s manual on getting the carb set up and dialed in.
Good luck,
Mark
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well, looks like ill just rebuild mine, then if im gonna go through all of this for a new carb down the road i think im might look into a truck avenger, if they do as they say it will be a good invesment.