The carb of mystery

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billy

Motor mouth ratchet jaw!
Joined
Nov 15, 2009
Messages
3,935
Location
helifino USA
The mystery screws 1,2 and 3
And nobody knows what those ports are for
What they do
Or which should be plugged or where they should be connected
 

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Different vehicles and years have need for vacuum in different places and these are for that purpose.
If they are not needed then you do what you did and cap them.
The only thing you need on your ride is a vacuum advance port and a pcv port.
 
Vac lines - unless you have something that needs vacuum and isn't hooked up, leave those ports capped and don't worry about em (unless you're having engine issues - like your advance is hooked to the wrong port, etc.)

Screws - taking a guess, the 2 together look like fast idle and low idle speeds, the lower 2 look to be idle mixture?
 
Billy, I think the first two screws are: idle speed setting, and choke fast idle cam setting.
The screws in the third, fourth and fifth pictures are: the idle mixture settings. I usually set them at about 1&1/2 turns out and then adjust each one after that with the motor running and warm, until the motor smoothes out the most.
Yes, block off the unused vacuum ports, but make sure you use the right ports and block the others. I don't like the hose coming out of the side of your carb, as it might go to your vacuum advance and that doesn't look good to me. Tomorrow I'll look at some Carters and see where the vacuum lines come from.
 
Vacuum plugs don't require hose clamps. Just get a new assortment pack at the local auto supply and use them.
The hose on the carb doesn't need the clamp either just a new hose if it isn't one already.
If this is a power brake hose then it needs to be vacuum hose and not a piece of gas line. If it's a pcv hose then gas line will work.
 
Vacuum plugs don't require hose clamps. Just get a new assortment pack at the local auto supply and use them.
The hose on the carb doesn't need the clamp either just a new hose if it isn't one already.
If this is a power brake hose then it needs to be vacuum hose and not a piece of gas line. If it's a pcv hose then gas line will work.
The package of plugs i bought sucked.
They all got soft and sloppy.
Hose clamps wouldnt affect performance correct?
No power brakes
 
Billy, I think the first two screws are: idle speed setting, and choke fast idle cam setting.
The screws in the third, fourth and fifth pictures are: the idle mixture settings. I usually set them at about 1&1/2 turns out and then adjust each one after that with the motor running and warm, until the motor smoothes out the most.
Yes, block off the unused vacuum ports, but make sure you use the right ports and block the others. I don't like the hose coming out of the side of your carb, as it might go to your vacuum advance and that doesn't look good to me. Tomorrow I'll look at some Carters and see where the vacuum lines come from.

Love to see whats what!
 
Billy,

I think your a may be way over thinking this. That carb is sold for lots of applictions. So it has a lot of extra ports.

If you put a vacume guage on the ports one at a time, you can figure out which one(s) are metered and which one(s) are full vaccume. Run a metered port for your vaccume advance on distributor and cap the rest. If you have a brake booster use the large port on the bottom to supply it. Set your Idle where you want it and set the mixture screws where you get the most vacume on a non metered port using your guage.

Not knowing what the engine was out of it's kind of a crap shoot. It may be an old well motor or something. They made a ton of 318s for alot of applications.

If you want to wake up a weak 318 for your rig it will most likely involve a RV type cam, an intake and a carb and a elecronic dizzy that are all chosen to work together.

I don't know that my worthless opinion helps but it's something to think about.
 
Billy, I was wrong about the vacuum line to the distributor on a Carter carb. Here are some pictures of the plumbing on some Carters. The side port does go to the distributor. The small back port goes to your 'choke pulloff' pot. That little pot pulls the choke partway off as soon as the engine starts and there is vacuum.
Sorry about scaring the wits out of you with my opinions.
 

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Billy,

I think your a may be way over thinking this. That carb is sold for lots of applictions. So it has a lot of extra ports.

If you put a vacume guage on the ports one at a time, you can figure out which one(s) are metered and which one(s) are full vaccume. Run a metered port for your vaccume advance on distributor and cap the rest. If you have a brake booster use the large port on the bottom to supply it. Set your Idle where you want it and set the mixture screws where you get the most vacume on a non metered port using your guage.

Not knowing what the engine was out of it's kind of a crap shoot. It may be an old well motor or something. They made a ton of 318s for alot of applications.

If you want to wake up a weak 318 for your rig it will most likely involve a RV type cam, an intake and a carb and a elecronic dizzy that are all chosen to work together.

I don't know that my worthless opinion helps but it's something to think about.
THAT IS WHAT I NEEDED!
clear simple instructions that i can methodically follow.
Thanks!
 

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