Adjusting Carter B&b Question

[wdoland]

Pulled my sparkplugs and found them fouled with black carbon. They aren't too old so I'm probably running too rich. Do I take the screw in till it starts to stall then back it out a little?

[Don Coatney]

The pictured screw in question only adjusts the idle mixture.

 

 

Where is your accelerator pump linkage set? There are 3 positions. Most squirt, medium squirt, and least squirt. Also known as winter setting, spring-fall setting, and summer setting. Pictured below is how I have mine set for the least squirt (summer) setting.

 

[wdoland]

Thanks, Don. I didn't know about the accelerator pump linkage, but I'm learning. Does that effect how rich it's running?

[Plymouthy Adams]

it affects the CCs (volume  of fuel) delivered with the stroke of the pump..is the plug oil fouling or actually over rich..

[wdoland]

I think it is running rich because it wasn't oily it was pitch black but came right off like a powder. My accelerator pump linkage is set in the middle hole. I guess I'm in the spring/fall hole and should be the one to the left. Farthest away from the rod, like Don's photo. Would that take care of it running rich? 

Edited August 21, 2013 by wdoland

[ptwothree]

A choke that is partially closed or a seized metering rod piston, stuck in the up position,  will cause a rich condition. Or a float level set too high. So will a weak spark.  Sounds like a carb rebuild is a good place to start.

[wdoland]

So the idle mixture screw has nothing to do with a rich condition? If it does how do I adjust it?

[TodFitch]

So the idle mixture screw has nothing to do with a rich condition? If it does how do I adjust it?

Idle mixture screw adjusts the idle mixture. When you are driving your engine is not idling. . .

 

Re-read post #6 above.

[wdoland]

If I ask what seems like a dumb question to you might mean that I just don't understand the answer. Please excuse my ignorance. Telling me to re-read something is not going to help.

I have been reading that the idle mixture screw DOES effect carbon fouling and how rich the mixture is but no one is saying how to adjust. This carb was rebuilt when the engine was overhauled and appears fine. I would like to start with the basics first and not jump into a teardown just yet.

[Merle Coggins]

Try following these directions. It's for Weber carbs, but it will work the same on your Carter.

http://www.redlineweber.com/html/Tech/carburetor_set_up_and_lean_best_.htm

[Don Coatney]

The idle needle valve is used only when the throttle butterfly is closed and the engine RPM's are low. To adjust it screw it all the way in gently, then open it 1 1/4 turns as a starting point. Then start the engine and adjust it in or out until your engine idles smoothly. Once you open the throttle butterfly the idle circuit is no longer used.

 

I dont recall but have you done a compression check on your engine? If you remove the oil fill cap with the engine running how much smoke is visable in the fill tube? Is there any visible smoke coming out of your exhaust pipe? If so is it white, blue, black?

 

And from post #6, Is your choke butterfly fully open? And what is your carb float level setting? Answering those questions will help in fixing your problems.

[wdoland]

I have not done a compression check. I guess I'll do it this weekend. I did notice a little grey smoke coming from the oil fill cap the other day after I went for a short ride and shut it off. I will look with engine running. There is greyish black smoke coming out of the tailpipe only when I bump the throttle but I figured the car hasn't been running for about 3 years and I have only driven it a few times around the block. Haven't blown out the cobwebs yet. The engine was rebuilt before it was parked (I have paperwork) and past owner said he put about 500 miles on it after the rebuild then parked it.
So I'm hoping the compression test will be good and the smoke and carbon on the plugs is just from being out of adjustment and from sitting for so long.

 

[Don Coatney]

Sounds like you need to take it on a hundred mile drive and then check the plugs.

[P15-D24]

Sounds like you need to take it on a hundred mile drive and then check the plugs.

Agree with Don. 

[greg g]

Within the carburetor is a step up valve. This works on a vacuum signal generated i the intake manifold and passed up through the carburetor. You car engine generated it most vacuum when idling or with a steady cruise with a stable throttle opening. When you accelerate, the vacuum drops then builds as the engine speed matches the throttle openining where it restablishes it self. When you open the throttle, the accelerator pump gives a short shot of extra fuel. This only happens once and quickly enrichens the fuel mix for a short time. As acceleration continues or climbing a hill goes on and vacuum drops, a spring opens a tapered needle in another fuel jet, this enriches the mixture for as long as the low vacumm signal exists. When vacuum is re established it overcomes the spring and closes this jet for normal cruise. Here is the rub, that vacuum path is established by a slot in the carb to manifold gasket. It that slot is missaligned or plugged, there is no vacuum to close that jet, and you get an over rich mixture all the time. There is a hole in the base of the carb that fits over the slot and allows manifold vacuum to pull against the spring and keep the valved closed. If that vacuum path is blocked or the valve stuck open you will get poor fuel milage, black plugs and a heavy gasoline smell at the exhaust.

[greg g]

Also if you disconnect the fuel lie at the carburetor, you can then remove the needle and seat assembly and check it to see that it is not fouled with something that might hold it open. And open needle and seat will allow the fuel pump to contnue to fill or overfill the float bowl regardless of need, The extra gas will overflow and lead to partially flooding the engine. Next time you run it for a while, look at the base of the carb at the throttle plate pivot pin, if its wet you got a problem.

[wdoland]

Wow! Thanks, Greg. Now I know and understand what a step up valve does and how important vacuum is. I guess I should get another gasket ready if I pull the carb to inspect that slot. Also I tried to change my accelerator pump linkage to the "summer" position but after removing the (very small) clip that holds the linkage, I couldn't get the linkage out so I left it alone. I didn't want to force and break something. Since it's in middle position, and it's almost fall I'll leave it there.

Went for a long ride after work yesterday. Longest ride yet and everything seemed fine. Actually ran better after it warmed up.

Don, after my ride there was no smoke coming from the oil fill cap.

[Don Coatney]

Your service manual should have instructions for accelator pump adjustment procedures. If you dont have a service manual you should get one.

[greg g]

vapor coming from the oil filler cap is normal if not excessive.  It usually has three sources, condensed water vapor cooking off, prevelent after a few short trips where the engine never reaches full operating temp, normal vaporization of oil from full operatig temp, and heavy vapor caused by blowby of compression and entry of exhaust gasses into the crankcase due to worn piston rings and or cylinders.  If you have blowby, or if you have a heavy over rich condition your oil will have a smell of gasoline.  If this is the case you need to address what ever is causing the problem.  Here is where a compression testor or vacuum gauge properly read and interpreted will give you an idea of the internal condition of your engine.

[greg g]

Any update???

[48Dodger]

If you want to use your spark plugs as the "tool"  for what's going on....you can read your plug(s) immediatly after an engine event. 

Its a racing mentality, but useful for finding power lose.

 

Idle it til hot.....read it

crusie it.....read it

Hard acceleration.....stop, yank the plug out and read it. 

Hard pull, as in up hill which will fully activate the Step-up Jet....stop, pull it....and find at what point your carbon is developing. 

 

Its time consuming, but power tuning is important. Don't want to miss out on any available HP. 

 

How racing does it.

 

48D

[wdoland]

Update? I guess fouled plugs are the least of my worries. I was taking your advice about going on a 100 mile run to blow everything out and got around 50 miles. Battery wasn't being charged so I pulled the generator and had it rebuilt. Got it back and installed, polerized it and heard the gen whine when running. Talked to Plymouthty Adams in chat and loosened the belt and made sure it was oiled. Think I got that straightened out. Went for a test ride, pulled into driveway and heard loud thump. Grinds when going into reverse and funny clunking sounds when putting into low range or high range. It's always something! Don't get me wrong, I know these old cars need TLC and I'm having fun learning and working on it.

I think this car was a little neglected in it's day so it might be awhile before I work out all the bugs. The wires have me a little concerned. It looks like wires were added as others went bad, there are two voltage regulators. (old one and a new one) Both have wire hooked up to it. Other wires just disconnected and just hanging there.

Well that's my update. Sorry you asked? I'll get there, just taking it slow and easy.

Oh, I did buy a cool air freshner to hang on the rearview. But as far as the carb and spark plugs, it's running!

[greg g]

Check the Imperial club website for Semi Auto transmission trouble shooting.  Something as simple as a too fast idle will can cause some of the problems you describe from your trans.

[White Spyder]

Two things. I just went through a fluid drive not operating correctly and it is documented in the tech archives. Hopefully following the thread will help you trouble shoot yours.

I think that a 500 mile run after a rebuild is not long enough to seat the rings so another few hundred miles is needed to do the job. Then start checking the plugs.

[wdoland]

I'm way ahead of you, White. Read it at work today. Glad you got yours taken care of.  To tell the truth, there were so many little things going wrong with my car that I kind of put the "clunk" on the back burner. But I worked on a few things, got the map light working with the pass. door switch. Installed my clock (and it works), converted my oil bath air cleaner to a paper filter then painted it and got a new decal for it. Took it for a run and it shifted fine. I think it's normal for it to slip or clunk when it's under a load. The only time it did it was going up my steep driveway and I was not giving it enough gas.

Keep us posted with more photos of your ride.

Wayne