chrysler49 Posted July 20, 2014 Author Share Posted July 20, 2014 I did replace those wires. I should go ahead and double check they're functioning as they should Link to comment Share on other sites More sharing options...
hchris Posted July 21, 2014 Share Posted July 21, 2014 Don't know the exact model off hand. Carter BB. Original to car; rebuilt a year ago and ran just fine.OK don't know how good you are with carbs, but you should know that there are two main fuel flow circuits in these carbs, first the idle circuit (kind of a misnomer because it actually regulates the fuel flow up to about 1500rpm), this is the circuit affected by idle mixture screw adjustment. The second circuit is known as the power enrichment or sometimes titled as the economiser circuit; disregarding the title, it is the circuit that regulates the fuel flow at higher throttle settings, which it seems is where you are having your trouble.Now as I recall, the Carter BB uses a vacuum control to open or close (depending whether you are opening or closing throttle) a step up piston with a very fine tapered rod that moves in or out of a power enrichment jet, to add fuel at higher speeds or reduce fuel as you close throttle, this mechanism is located in the float bowl. If this item is out of kilter you may well be dumping too much fuel in at high speeds, hence the sooty plugs.The power enrichment system gets its vacuum signal from the inlet manifold thru the carb base plate, it is very important that the carb flange gasket is positioned correctly so as the vacuum port is not blocked off, this may also apply to the float bowl gasket, as it may have holes as well to pass the vacuum through the carb castings.Failing all this, probably the only other item I would double check is the float height and needle / seat mechanism, if for whatever reason the fuel bowl level is too high then your mixture will be abnormally rich all through the range.Now one other thing, I recall you mentioned disconnecting the choke, did you actually ensure that the choke flapper valve was in fact fully open, check this before any of the other. Link to comment Share on other sites More sharing options...
RussJagoau Posted July 21, 2014 Share Posted July 21, 2014 If that model carburettor has a Power valve installed, that is held closed by vacuum and is opened by a small internal spring , then the backfire may have damaged the Power valve diaphragm, so that its open and enrichening the fuel / air mixture , these were designed for such applications as going up a hill or slightly accelerating when the engine loading and hence fuel demand is slightly increased. I had this happen once on a customers car when he inadvertently got the spark firing order wrong and created a backfire. It cleaned out the carb !!! but damaged the power valve. An old Pontiac I worked on one time had popped a metering needle out of the metering jet one day , that caused the fuel / air mixture to increase to give exactly the same symptoms as described , suggest to take a look at the metering system first for the idle mixture screw wont be the culprit based on the symptoms described.... Link to comment Share on other sites More sharing options...
chrysler49 Posted July 21, 2014 Author Share Posted July 21, 2014 (edited) This actually seems like a likely culprit. Offhand I can't say if it has the power valve diaphram, so I'll have to check it out later.Update: doesn't seem as though my particular carb has a "power valve" that I can see. Adjusting the mixture screw does nothing to change the idle of the car, but I've cleaned the hell out of the passage. Edited July 22, 2014 by chrysler49 (see edit history) Link to comment Share on other sites More sharing options...
trickydicky43richard Posted July 22, 2014 Share Posted July 22, 2014 If you need help with your carby can I recommend Ted Dudley in Florida, Ted is good value and is an old school gentleman Carby whiz working from home , he had my Chrysler B & B Carby problem sorted in no time, Ted's email is thrsty9@gmail.com.Try him too if you want a multiple carby performance set up !Rich Link to comment Share on other sites More sharing options...
RussJagoau Posted July 22, 2014 Share Posted July 22, 2014 This actually seems like a likely culprit. Offhand I can't say if it has the power valve diaphram, so I'll have to check it out later.Update: doesn't seem as though my particular carb has a "power valve" that I can see. Adjusting the mixture screw does nothing to change the idle of the car, but I've cleaned the hell out of the passage.That's correct, the idle mixture screw effects only the slow speed or idle circuit for fuel / air ratio, not the high speed circuit fuel delivery. It wont have any noticeable effect on your high speed circuit inside the carburetor unless the idle jet has dropped out ....Having said that , you mentioned that the idle mixture screw has no effect on the idle speed, if you close the screw fully the engine should stop as it leans the mixture off. If the screw is fully closed and the engine still runs, then there is an internal problem in that circuit as well < maybe the idle jet has come adrift ??? This would then also enrichen the main air / fuel ratio dramatically but generally they wont start if that's the case.... I had a look at the BB Carb manual, on the high speed circuit there is a vacuum operated spring opening metering needle / piston which controls the main air / fuel ratio, this is the one to inspect and make sure all is ok there. The metering needle and jet wear over time and can lead to richening the mixture, but your symptoms appeared after the backfire..... There is usually 3 things that effect the main fuel / air ratio, ie metering jet and needle size, float level and choke operation.... I can send you the carb manual if you wish, drop me a message and I can email to you. If the engine idles smoothly then its not a vacuum leak either and if it was the case, highly unlikely to run rich on the main fuel circuit..... Link to comment Share on other sites More sharing options...
chrysler49 Posted July 27, 2014 Author Share Posted July 27, 2014 Took the carb back off and dismantled and Recleaned everything I could get to, leaving only the main vent tube as I dint have the tool to remove and install that. I cleaned and readjusted my choke and installed a new gasket. I also finally fixed the manifold heat valve spring and installed all new plugs. After all that, it took 2 miles for my plugs to be black and sooty and it continues to bog at 50-55 mph. Still can't kill the car if I turn the idle mixture all the way in while idling either. Could that main vent tube really be the cause of this? Place to get that tool is only open Mondays and Tuesdays... Link to comment Share on other sites More sharing options...
hchris Posted July 28, 2014 Share Posted July 28, 2014 Took the carb back off and dismantled and Recleaned everything I could get to, leaving only the main vent tube as I dint have the tool to remove and install that. I cleaned and readjusted my choke and installed a new gasket. I also finally fixed the manifold heat valve spring and installed all new plugs. After all that, it took 2 miles for my plugs to be black and sooty and it continues to bog at 50-55 mph. Still can't kill the car if I turn the idle mixture all the way in while idling either. Could that main vent tube really be the cause of this? Place to get that tool is only open Mondays and Tuesdays...Perhaps the only way to rule out the carb is to source another one if possible, another thought, do you happen to be running an electric fuel pump? also what do you know of the history of the existing pump?Now I wonder if the pump is over pressurising the carb float mechanism, these engines should only run on maybe 1.5 - 2.5psi, if you can measure the pump pressure that might be useful. Link to comment Share on other sites More sharing options...
trickydicky43richard Posted July 28, 2014 Share Posted July 28, 2014 After reading more of the posts it seems no one has questioned the size of your Carby jets etc, are they correct ones ?? is it the correct Carter Carb model for your engine size. I have mentioned before,Ted Dudley in Florida can build you a correct Carter BB Carby and he is very reasonable with his rates, worth a try. Link to comment Share on other sites More sharing options...
impacsys Posted August 5, 2014 Share Posted August 5, 2014 i did a compression check on my 26 s70 and all six cylinders where 85psi. also did a complete tune, coil, cap, wires, plugs, points and condenser. I am runing a modern zeinth carb. it runs good, maybe not great. Should I adjust values? Link to comment Share on other sites More sharing options...
c49er Posted August 5, 2014 Share Posted August 5, 2014 (edited) After reading more of the posts it seems no one has questioned the size of your Carby jets etc, are they correct ones ?? is it the correct Carter Carb model for your engine size. I have mentioned before,Ted Dudley in Florida can build you a correct Carter BB Carby and he is very reasonable with his rates, worth a try.I questioned the carb jets and posted Carter info over on the P15-D24 site for him. I don't think he can dechyper it . These help me fix it threads are sometimes endless. Edited August 7, 2014 by c49er (see edit history) Link to comment Share on other sites More sharing options...
gregchrysler Posted August 7, 2014 Share Posted August 7, 2014 what about vacuum advance -spring may be broke in distributor on advance plate- also try putting old condenser back in Link to comment Share on other sites More sharing options...
chrysler49 Posted August 14, 2014 Author Share Posted August 14, 2014 Carb is original and the jets are correct. Car's mixture was fine before tearing into it earlier this summer, so I'm not going to bother worrying about jet sizes. Link to comment Share on other sites More sharing options...
Guest paulo windsor Posted August 14, 2014 Share Posted August 14, 2014 Hello chrysler49I am from Portugal and with my 47 windsor I had a problem 10 years ago just like that. After many tests and spending too much time and some money too, a friend of mine remembered to check the float needle seat at the entrance of the carburator where the fuel pipe enters ,but it wasn't a usual checking because he noticed that the size of the hole inside the seat was in rubber and the size of the hole wasn't enough too provide enough fuel to the engine. It took a drill to open the hole and the problem was solved just like that. We reach the conclusion that all those 50 years made the rubber to close the hole and to create a problem with the fuel passing. If your problem is the same I'm happy to help you solving it. But be careful the size of the drill can't be much bigger than the hole because the needle of the carburator seals on that rubber. I'm new in this forum and my english could be better but I hope you will understand it. Please reply me after you tested it to tell me if this fixed it.Cheers and I hope it works. Link to comment Share on other sites More sharing options...
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