carb question

[Rusteeze64GB]

Besides being a fire hazzard will a leaky carb keep a truck from starting. I have a 1 barrell Carter carb that is leaking all over and the truck will not start now. I thought I ran out of gas at first. I have a freshly rebuilt Rochester 1 barrell ready to go. Looking at the rochester it looks a little different to get it going opposed to the Carter. Any info as far as starting and not starting and mounting of the rochester will help greatly. Thank you.

[markeb01]

It certainly can keep it from starting. Ideally the optimum theoretical ratio of air mass to fuel mass is something near 14.7 to one. With an engine drowning with fuel, there won't be enough air in the mixture to allow ignition (as in a flooded engine). Can't help with the mounting issues, it's been about 45 years since I've owned a one barrel carb on a Chevy 6.

[Rusteeze64GB]

so the top picture is the old carb I thought was a carter actually is a rochester. The second picture is my freshly rebuilt rocester monojet 1 barrell. So I did the swap and the truck still will not start. I am beginning to thing the truck does not want to be on the road.

[Rusteeze64GB]

I dont know if the rod in th second picture will have anything to do with the truck starting or not. It looks good. I am now wondering what my problem is. I put on a fuel filter this morning and seems like ever since the truck wont start. Any input would be great.

[markeb01]

I don't see any choke connections going to the new carb (actually from the one picture I don't see any indication of a choke even being present). The rod going nowhere is connected to a thermal spring on the exhaust manifold that turned off the automatic choke on the old carb when the engine warmed up. If the new carb is manual choke, it will need a cable hooked up to the linkage to allow it to operate. You might try pulling the air cleaner and manually closing the choke and see if the engine starts. At least that would narrow the things that need to be looked at.

Also, if the old carb has been leaking for a long time, you'll probably need new spark plugs. Excessive fuel will foul the plugs and replacement is the best fix.

[Rusteeze64GB]

Thank you for the reply sir. It helps alot. I have not changed the plugs since I got the engine. It did run this morning but it was running real rough and back fired a few times. It's seems like when I put that new fuel filter on it just stopped running and that old carb started leaking like crazy. I was going to replace the plugs and the coil this weekend anyways. When I pulled the old carb off it was flooded with about 1/2 inch of fuel in the manifold. It was crazy. I do have a choke for the new carb but it is on the back side and I think it is manual one, I am going to have to rig something up. Thank you again for your input it helps alot. It was real frustrating today. I have started this truck once to twice a week for the last 6 months and it has started every single time today was the first day it would not start. I was told that the choke thing on the manifold is not too big of a deal to be hooked up? Does that sound right? I finished my brake job today and did other odds and ends I am hoping ot be on the road with it soon.

[ConnDemned]

I had a monojet on my 78, and everyone I talked to about them said they had lots of problems even on rebuilt ones. So I switched to a 2 barrel Holley. Anyway, have you tried to get all the excess gas out of the manifold, clean the plugs a bit (yes I know new plugs are ideal but cleaning the used ones to test a theory won't hurt much) and seeing if she'll fire up? Also check for vacuum leaks at the manifold/base mount. I would also set the air/fuel mixture screw to a "bench neutral" or a good starting point if possible, who knows if someone messed with it and its way off now. Good luck, I don't regret tossing my monojet at all, got tired of it flooding out on the road and trying to get it cleaned up and running just to make it home or work.
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[markeb01]

First up, if there is that much gas in the manifold, you should pull the plugs, disconnect and plug off the fuel line, pop the cap off the distributor and crank the engine to clear the cylinders. If they are filled with liquid gas, you could end up bending a connecting rod. Also, be sure to change the oil as that much gasoline in the cylinders will likely seep past the rings and dilute the oil in the crankcase.

If it just started flooding since the filter addition, it's very likely a piece of crud was dislodged in the fuel line and caused the float “needle and seat assembly” to stick open. When the happens the incoming fuel doesn't shut off, it just keeps pumping in more fuel as long as the fuel pump is operating by cranking the engine. If this is the case, the carb could possibly be easily rebuilt with a carburetor kit (most include a new needle and seat) and a couple of cans of carb cleaner. It could then be simply reinstalled as stock, although the Monojet design may be questionable for reliability.

Most cars with an automatic choke in the 50's and early 60's used a round style choke housing on the side of the carb. It had a bakelite cover, usually with 3 retaining screws. Adjusting the choke setting was simply a matter of loosening the screws and rotating the cover to the desired setting. These frequently had a tube attached to the exhaust manifold that attached either to the carb itself or directly to the choke housing cover. Hot air from the exhaust manifold caused a thermal spring to open the choke as the engine warmed up.

The type you have with the link was introduced in the early-mid 60's, and if memory serves correctly was called a "divorced choke". Adjusting them was a matter of bending the link. The manifold choke link is easy to hook up, but from a practical standpoint must be attached to a compatible carburetor. I don’t think it can easily be adapted to your new carburetor. If you choose to remove the link, there is normally a sheet metal cover attached to the manifold with one or more screws. Once the cover is removed, the lower leg of the arm can simply be slipped out of the loop on the thermal spring.

Any more questions ask away, there are many on this site with lots of experience. Good luck with your project.

[fleetsidelarry]

the only thing I might change about markeb01's advice is popping the distributor cap since the spark plugs are on the same side as the distributor and you would have a cloud of fine gas droplets spraying around a set of sparking points. maybe disconnect the wire from the coil to the distributor?

I've done what markeb's suggesting (spinning the motor to flush the gas) with a V-8 many times, but the distirbutor isn't so close to the plugs

(its been so long since I've ran a set of points (or had an inline 6) that I'm operating off of memory cells here and there aren't many left)

[Rusteeze64GB]

man this sucks.

[Rusteeze64GB]

Thanks fella's. I think I am going to change the plugs for sure. I will probably drain the oil too. when I noticed the swimming pool of gas in the mani I took a clean rag and soaked up almost all of the gas out. I made sure it was dry before I put the monojet roch on. So, would the better suggestion be to try and rebuild the carb that i just took off and reinstall it? I am really at a crossroad here. IT's seems like when I added that fuel filter it would not start. Could that be the culprit since the carb already has a filter built into it?

[fleetsidelarry]

Rusteeze, I'm a little confused about the sequence of events.

yesterday you said it ran briefly. was that with the newest carb?
and now it won't run at all? raw gas was from the first carb? any raw gas with the second carb? is the new carb getting gas (I mean, silly as it may sound, you may now be out of gas(oline))

[Rusteeze64GB]

It ran before the carb change. I have not checked to see if I have the same problem with the rebuilt carb. I did put 2 gallons of gas in the truck after installing the rebuilt carb. I had that bright moment before.

[Rusteeze64GB]

When it ran yesterday, with the old carb, it was back firing and stumbling, it was running real rough.

[markeb01]

Originally Posted by fleetsidelarry

the only thing I might change about markeb01's advice is popping the distributor cap since the spark plugs are on the same side as the distributor and you would have a cloud of fine gas droplets spraying around a set of sparking points. maybe disconnect the wire from the coil to the distributor?

I've done what markeb's suggesting (spinning the motor to flush the gas) with a V-8 many times, but the distirbutor isn't so close to the plugs

(its been so long since I've ran a set of points (or had an inline 6) that I'm operating off of memory cells here and there aren't many left)

Excellent suggestion. It's been so long since I've worked on a six it never occured to me about the proximity of the plugs and the distributor.

Another thought about the old carb, when installing an inline filter, I always discard the filter in the carb inlet. Both the porous bronze and paper types plug up easily, but bronze filters plug up even faster.

[fleetsidelarry]

Originally Posted by Rusteeze64GB

When it ran yesterday, with the old carb, it was back firing and stumbling, it was running real rough.

so, it won't start at all with the new carb or you haven't tried it?

[Rusteeze64GB]

it wont start at all with the new carb. I am going to look at it tommorrow. I will post my findings if I still cant get it running tomorrow. Thanks again guy's, it has been very insightful.

[fleetsidelarry]

just a thought, double check to make sure your timing is still OK, backfiring can actually cause the distributor to move, especially if it has one of those wire-type hold-downs. seems I remember the 6's being prone to that.

[Rusteeze64GB]

I had foulded spark plugs. They were charred. I changed the plugs, adjusted the timing a little. She fired right up. I am prettty happy, the truck runs smoother than before. Thank you for the advice, I put it all to use.