Carb rebuild questions from a rookie

[Gweiner]

Don't laugh but I am doing my first carb rebuild. On disassembly I found a siliconed closed port. See pic. Is this for a vacum line? Also noticed elec choke has been disconnected (I think). My 74 had a manual choke that was removed by PO and I was told that I did not need it living in the south (I live in NC). Should I try reconnect wither of these?
Doing the carb rebuild bc it seems to be running really rich with some bad fumes.

 

[Slowleak]

The PO may have it running rich to compensate for the choke not working properly.. The plugged up hole is for the heat tube intake which provides warm air to open the choke. You should have two tubes going from the manifold as in the diagram below. If you don't have, or want the tubes, you could install an electric cap. Tubes are better.
If the black choke cap on the carb does not have a tab for an electrical connection then it is not an electric cap. Thats ok as long as the heat tubes are hooked up. I don't agree with whoever said you don't need a choke. Any engine needs a richer mixture until warmed up.

 

[CopperRanger]

http://grantorinosport.org/BubbaF250/carb/carb02.html
http://grantorinosport.org/BubbaF250/carb/carb02a.html

The second picture is the throttle solenoid.

 

[Gweiner]

Thanks slow leak and copper ranger. Very helpful. I have the two heat tubes, so that's good. The throttle solenoid black wire was cut. Should I reconnect? Wondering why it was disconnected in the first place.

I failed to mentioned that i recently installed a new exhaust BC Broncos 2 to 1 kit with a 50 series muffler and 2.5 inch out the side. Thinking carb might need to be leaned out a bit to accomodate additional exhaust flow?

Thanks again for all the help!

 

[k13evin]

Is that the 2100 or 2150 motorcraft? Those solenoid on the 2150 are there to bump the idle up most the time if you have AC. So it gives alittle more rpm. One of the best carbs. You can clean and have that thing rebuilt in 1 hour

 

[Slowleak]

I have a 77 with a/c but I have not found a need to wire up the solenoid. I think they were used more to prevent dieseling. It just adds another point of failure unless you have a need to use it.

 

[Gweiner]

"I See!" Said thre blind man. That makes sense, the truck came with an old A/C unit that was unhooked. I have since removed the compressor. Will remove the solenoid if its not needed (no A/C) .

Almost done. Just couldnt find a diaphragm at Autozone today. The guy behind the counter was useless. Will need to look elsewhere.

Thanks again for everyones help. Would not have attempted to do a carb rebuild without this amazing site and support from people on here.

 

[broncnaz]

Typically when a exhuast system is added you need to richen up the mixture as a better exhuast tends to lean things out couple that with todays gas which is somewhat leaner due the ethanol in it and it may have been lean before the exhuast was added.

Might try these guys if you can find the daiphragm locally. Try NAPA the part number should be CRB 24781 made by echlin
http://www.carburetion.com/ford2v.htm

 

[jckkys]

The idle stop solenoids were only there to deal with dieseling or run on after the engine is shut down while hot. The emissions settings included a more open throttle, just to idle. So there was enough air for the engine to run on with no spark. With the solenoid, when the ignition switch was killed the solenoid let the throttle close completely. If the idle and timing are set to run well, there is no dieseling, so no need for the solenoid.
The diaphragm is a more positive de-choking device than the piston in the choke housing. They work well, far more useful than Autozone counter guys. They were part of '71-'74 2100s. The earlier 2100s didn't have them and 2150s came out in '75. You can get them at Walker Products part #64-278;https://buy.walkerproducts.com/carb...d-2bbl-2100-2150-7-carburetor-components.html. AC wasn't an option on early Broncos. Either a PO or dealer installed it.
The hose nipple filled with silicone supplies filtered air to the heat tubes. You want it. You will learn that previous owners are often knuckleheads. I doubt your 2100 ever had a manual choke, but it did have an electrically heated choke cap.

 

[Gweiner]

Update: Carb rebuilt and back on. Looking good. When I went to reattach awrapped metal line on the choke side that was attached to the exhaust manifold and it crumbled from rust. Do I need this back on?

 

[Slowleak]

Yes....you need the tubes. That supplies heat to open your choke. See my earlier post above with the diagram. You can buy the tubes.

 

[jckkys]

Here's a good thread on Ford Truck Enthusiast that explains the system, with a good photo;http://www.ford-trucks.com/forums/1157890-choke-stove-setup.html. You clearly need new tubes. Most of the classic Mustang parts houses have them in steel and stainless. Classic Mustang suppliers are better for OE engine parts than Bronco venders.

 

[Gweiner]

Thanks guys. Hope I can the rusted piece out of the manifold...

 

[Gweiner]

Do i need that line connected to the choke for it to start/run? Cant get it to fire up. Its 80 degrees out. Any tips on first time starting after a carb rebuild?

 

[Slowleak]

Do i need that line connected to the choke for it to start/run? Cant get it to fire up. Its 80 degrees out. Any tips on first time starting after a carb rebuild?

No..... Make sure you have the mixture screws backed out about 2 turns. Check to see if it is squirting gas into the carb throat when you pump the gas. If not, i would pull the top off the carb to make sure you are getting fuel in the bowl. You can crank it with the top of the carb off.

 

[jckkys]

The rusted stump still in the manifold may have to be driven or drilled out. I removed the manifold to do mine. If you replace them with the stainless version, it should be the last time.

 

[Gweiner]

Thanks. Will try that next. I didnt touch any set screws but will double check. Smell gas and there is some in the carcb

 

[Gweiner]

Update: starts, but roough idle and will stall unless on the gas. Backed out mixture screws just two turns. Should i try a bit more? Sounds like it is starving for gas. So close!

 

[Slowleak]

You want to adjust those with the engine warm. Turn your throttle screw on the drivers side until it runs fast enough to stay running. Then turn your mixture screws 1/4 turn at a time, each screw the same amount, until the speed increases. Then turn the throttle screw back out to slow down the engine. It should smooth out. When it starts to run rough again you have gone too far. Also check to make sure all your hoses are connected and you don't have a vaccuum leak.

 

[Gweiner]

Thanks slow leak. Where should i start with the idle screw? All the way in or backed out? Sorry for the dumb questions. Cant get it to idle by myself. Also, confirming this is tbe idle screw? Also, should I be adjusting choke at all?