225 holley 1bbl flooding

-
mopar56

mopar56

Well-Known Member
Joined
Jun 19, 2014
Messages
937
Reaction score
347
Location
Vancouver island British Columbia
hi my son just purchased a 74 Duster 225 1bbl, its a low mile car, after driving it a month or so it developed some carb issues, i rebuilt the carb, changed the fuel filter and all the rubber lines that were disintegrating it worked for a while but acted up again so I replaced it with a rebuild, that worked graet for a day then flooded again, badly gas everywhere!, I freed up the float through the needle inlet and checked the needle/seat, it looked fine and no debris in the filter, I drove it again tonight and it ran fine, i replaced the cap/rotor/pcv and checked the plugs, ( they are some what worn and will get replaced this weekend ), I ordered another carb from the supplier, ( parts plus) I bought it from and it should arive Friday, hopefully thats it, any slant six carb woes I should know about?, thanks
 
its hard to find a carb from a rebuilder that is 100% right. (if it built from a core and not an unused OEM part, I would look it over real good) One of the main problems is the "makeup" of the gas nowadays. Alchohol is just not a good ingriedient if you have old style parts in the carb, specifically the accelerator pump and the needle and seat.(or other part that are made of rubber).
 
Most new needles and seats are made to take the alcohol of today; I guess there can be some older ones out there.....but a good carb kit will have the newer type.

Your problem is likely that the tank is full of crud and the fine crud keeps getting up into the carb and past the filter. Until you pull that tank and clean and inspect for rust, you are going to still have issues. Also check the line between the filter and carb for rust in the inside. It is pretty clear that you are getting crud into the needle valve form somewhere.

Also, if you adjust the float, do not just push up against the float to bend the float support with the needle against the seat; it can damage the needle/seat that way.
 
agreed about the rebuild thing I normally avoid them but my options were limited here, as far as the fuel issues go we dont have the same fuel issues you folks have in the US, as far as the make up of the fuel content but it is coming, that being said as this car was from the US it did have some deterorating rubber lines so I changed them all, also I installed a new clear filter near the carb and it was very clean at the time of flooding, on this model of carb you can remove the needle/seat completely as it screws in where the fuel line goes, I did this and inspected it and everything was clean and clear, I slight tap to the float, ( very gentle), put the needle valve back and all was well, I really feel the float just hung up somewhere inside, we are going to continue driving it and replace the carb again Friday
 
thanks, I may try that mod if we experience the vapor lock but I think at this time I had a stuck float, the venturi was FULL of fuel and pooring out the base gasket, thanks, I think what I was wondering here was a very long time ago I owned a slant six 70 dart with point ignition, the carb was always flooding, turned out the points were burnt out and there was very little spark to process the fuel, now this car is electronic ignition but what if the control box were bad?, could spark be weak enough to do the same thing?
 
If the float is what looks like brown foam, it can absorb gas, get heavy, and not work correctly.

I recently replaced a nitrophyl float in a Holley 2280 that lasted less than a year. The weight of the removed float, was a gram heavy. While the float was adjusted properly, the engine ran rich. A new float fixed the issue. I am working on a coating, to see if that will provide a longer term fix.
 
good idea but this one is brass, so what dose anyone know about charcol canisters and there operation?, so I started the car tonight, ( it hadnt run since yesterday), the choke came on and it ran well, then when I tugged the throttle and took it off high step it stalled, I looked down the throught of the carb and once again gas was pooring in through the squirt nozzle and started pooring out the base gasket, I tried tapping the side of the carb but it wouldnt stop, I removed the needle/seat for inspection and it was clean, so I tapped the float gently with a small flat tip then re-installed the fuel line and re-started the car, all was fine, so back to my question, what about the charcol canister, currently only one hose coming from the fuel tank goes to the canister there is another nipple on the top of the canister that is open and no hose in sight that would go to it and the other nipple is broken with no line I could find that would go to it, then I removed the one line from the tank to it and blew back through it and I can not get any air to pass, is there a one way valve in the tank? or is it plugged?, if its plugged could too much pressure build causing the needle to flood?, maybe there needs to be vacuum to the canister to vent the tank?
 
yeah I just blew through the hose, ( mouth pressure), so its not hot day temps, where I am its only in the 70,s and it flooded right after coming off choke, the exhaust manifold wasnt even hot yet, I would think maybe there is a check valve of sorts at the tank preventing me from blowing back?, I could be over thinking this I am sure its just a poor quality carb rebuild, guess I will wait untill tomorrow to find out.
 
well the new rebuilt carb cam in yesterday and I put it on, fired it up and it started flooding before it even came off the hi step completely and when it did, it flooded out and died same as before, once again I checked the needle/seat and fuel filter for debris, none present, I put the old carb back on, ( the origanal that I rebuilt), and it started right up, I drove it around a few miles and it was still good, I started it this morning and still good, drove it 4 miles, still good, I gave it back to ny son to take to work today, ( about a 8 mile round trip), so I will see how that goes, I guess those two rebuild were just junk, I will follow up later
 
yeah, good thought, I deal with a lot of fuel injection stuff at work and it dose seem like its pressure is to high, but its just a mechanical pump, even if it had been changed in its life I think about the most a mechanical pump will do is 7 psi and the needle should hold that no problem, I am takeing back both carbs today and keeping my origanal
 
OK, just trying to figure out why the problem is so persistent. Your rebuild and then 2 other carbs all flooding seems too much to be just concidental. Either pressure or dirt.....any rust inside the line from the filter to the carb?? BTW is this the Carter or the Holley carb?
 
hi, sorry to take so long to get back, I had a busy weekend, like the thread says its a Holley 1bbl, a 1945 series, but in doing some research it appears that 73 Dusters might have used a Carter 1bbl?, if so why couldnt I use one of those if I could find one?, and well all these carbs did flood, they did so in a different way, The first one I did flooded once in a while but was drivable the second one that I purchased worked well for a day then flooded, the third didnt even make it off the high step before it flooded, I took the two rebuilds back to the parts store and put the origanal back on, its hit and miss but still floods, I know what your thinking, ( debris in the carb) but its just not so, I have a clear fram filter on so I can see any debris and its clear and each time it happens I remove the needle for inspection and its clear, the float simply sticks and when I manually free it up all is well?, any idea what Carter carb, ( series # ) I could use instead of this Holley?
 
Just for grins, have you put a fuel pressure guage on the fuel supply line? And, when you adjust the floats, are you holding the float to keep any and all pressure off of the needle and adjusting the tang that presses against the needle with some needle nose pliers?


And do you have any way to measure the small float weight, like a scale for powder loads? I would take out the float, wipe it dry, and immediately weight it; it should be on spec within +/- a coupla tenths at most. The old carb could just have a gas-logged float.

Look at the Carter BBS series; they were used on the /6's.
 
I was thinking of checking the fuel pressure tonight after work, the float I installed at time of rebuild was new and yes pliers and bend the float tang, ( not against the seat), I dont have a scale but I will inspect for leaks when it is dry, as far as the carter bbs series it requires the choke " stove" I believe and ours uses the electric relay with choke bimetalic spring which I like better so not sure what to do there, what do you think the fuel pressure should be? 7psi maybe?, also just think outside the box here, how is the fuel tank vented, through the fill tube like a truck maybe?
 
fuel pressure...a lot of the new pumps sold today put out too much pressure. for the old carbs
 
3-5 psi seems right....7 psie seesm high. My FSM is 500 miles away so I can't look it up quickly.

You should be able to look up the tank vent system on yours online.....I am just not in a position to do so right now.... at a jobsite 500 miles from home.
 
ok thanks, I didnt work on it tonight as my son hasnt come home yet, ( kids) so I guess its tomorrow, cant seem to find the vent source exactly, too many different answers, I wish I knew for sure if ait should blow back the charcol vent line or not, I have a feeling there is a check valve in the tank, thanks again for the help
 
On a US spec 74, there are 3 lines the charcoal canister. The line going towards the fuel tank goes through an overflow limiting valve (check valve to keep raw fuel out of the canister) and a liquid vapor separator. Others go to the carburetor. IIRC, the connections are labelled on the canister.
 
well I got back to this thing Tuesday morning 7am (Canada day holliday), I tokk off and apart the carb again, clean as a whistle inside, made a slight adjustment to the float, seemed it may be sticking to the bowl on one side?, checked the needle, good, disconnected the line for the purge at the tank under the car,( there is no other vent), tried blowing through, nothing, so removed the hose at the purge cannister and where it connects to the vent line, found the tiny check valve and cut it off, then blew through with mouth pressure, not much air, reconnected things, note: only one vent hose hooked up at the purge as others are long gone, went for a drive and all was well so far...we will see what happens, maybe a plugged check valve?
 
well...day #2 and still running strong, my son has put about 100kms on it since yesterday traveling both hwy and cty and so far all is well, so was it the float adjustment or the vent?, maybe a bit of both but I a really think that blocked check valve was pressurizing the fuel tank and possible making the fuel push past the needle/seat, anyway hopefully this is it, thanks for all the helpful suggestions guys!, I will keep you posted good or bad just for the record
 
I am just not clear on the source of pressurizatoin, unless it was fuel expansion in the daytime. Hope it styas good!
 
well the locking fuel cap on the car says its non vented and the fuel fill tube dose not have a vent line running beside it or anywhere else, the only other line from the fuel tank other than the fuel line from tank to carb is the small vent line to the charcoal canister, I wonder if one of the two missing lines to the canister went to a vacuum source to the carb therefore creating a suction draw from the tank De-pressurizing it? otherwise where dose the pressure from the heat of day go? too much pressure in the tank could cause the line pressure to the carb to increase and cause the needle to blow off the seat, ( that's my theory), I could be wrong here maybe I just didn't have the float setting right although I didn't adjust it that much, either way I am happy, and so of course is my son
 
You must log in or register to reply here.
-

Back
Top