carb problems
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New User
Joined: Apr 2005
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carb problems
i have a 1969 ford f100 truck .it has a 360 motor that has been bored .030 it has a 544 lift crane cam and headers. it has a stock 4 barrel manifold off of a 390 motor.i recently bought a used 650 carter carb. i had a holley on it before and it used way too much gas. the problem i am having is it stumbles when i first give it gas but takes off after this. i dont have a manuel for this carb so i was wondering if someone had any advice on adjusting this card including the acceleratorpump.also it doesnt have much bottom end torck. is this do to the high lift cam and can i cure it with a stall speed convertor. thanks for the help
Freshman User
Joined: Mar 2005
Posts: 39
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From: upstate NY
stumbling, from a start w/a carbed engine is usually a lean cond. ck. the acc. pump link. carter carbs are not easy to tune (at least for me) Your holley on the other hand can be tuned to whatever you like (for the most part) there are tons of jet, power valve, acc. pump,ect. available ck. around with the guys that race or used to and I'm sure you'll find some help. get the engine right then go after the tranny.
New User
Joined: Feb 2005
Posts: 12
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From: emmaus PA
when you say it stumbles at the start, do you mean when you floor it off the line? Because if thats what u mean, and considering its mechanical secondaries then they are set to open too early. Meaning you must pull the carb and set the secondaries to open at about 6/8 to 7/8 throttle. My stang has the same prob, but i prefer the mech seconds because i know there open and when it finally pulls out of the stumble it runs like hell.
Lead Driver
Joined: Aug 2003
Posts: 7,592
Likes: 10
From: **** hole San Jose ca.
You've bored it put in a high lift cam put on headers and now your trying to make it run lean. I'm not in to carters but if it was a holley, I would change the pump shooter jet size and matbe pump cam.. Like the other post said your can tune holleys and you can tune that carter, but if you don't know anything about super fine tuning a carb you better start with buying a few carb books so you'll learn how it's done. Did you read your plugs for a lean condition. How did you tune you engine timing points gap? and so on.. and for last maybe that carter needs to be rebuilt and that why it was sold. my 2cents 
orich
orich
Laughing Gas
Joined: Jul 1999
Posts: 1,048
Likes: 22
From: Lacey, WA
Hi,
Take a look at the accl pump linkage and you will see an arm with 3 holes in it that one part of the linkage is already in. Try moving the linkage to another hole. This changes the "when" the pump shot occurs. A rebuild manual will also tell you to bend the curved linkage rod to make "more" or "less" of an accl shot.
If you are running an older AFB then there is really no way to adjust "when" the secondaries open. Yes, the butterflies are controlled mechanically but there is a counter-weighted flapper valve above the secondary barrells that only opens when suffiecient(sp) air flow over comes the weight of the counter-weights. I have read that material can be removed from the weight to change the opening point but I am not that brave as once material has been removed it cannot be re-added.
The Carter carb is a good carb. Remember this is the carb used on 426 Hemi's that were burning up the streets in the late 60's. True that today they are not as infinately tunable as a Holley but they are good carbs.
I would get a rebuild kit and freshen that raskle up. I just did this to mine. It is an easy carb to rebuild.
Take care,
Lee
Take a look at the accl pump linkage and you will see an arm with 3 holes in it that one part of the linkage is already in. Try moving the linkage to another hole. This changes the "when" the pump shot occurs. A rebuild manual will also tell you to bend the curved linkage rod to make "more" or "less" of an accl shot.
If you are running an older AFB then there is really no way to adjust "when" the secondaries open. Yes, the butterflies are controlled mechanically but there is a counter-weighted flapper valve above the secondary barrells that only opens when suffiecient(sp) air flow over comes the weight of the counter-weights. I have read that material can be removed from the weight to change the opening point but I am not that brave as once material has been removed it cannot be re-added.
The Carter carb is a good carb. Remember this is the carb used on 426 Hemi's that were burning up the streets in the late 60's. True that today they are not as infinately tunable as a Holley but they are good carbs.
I would get a rebuild kit and freshen that raskle up. I just did this to mine. It is an easy carb to rebuild.
Take care,
Lee
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