Stewart Metering pin help

[cutdown]

Those check balls looked corroded to hell.  Float is ok.  I think the vac tank is working ok, but I can check that out as well.

 

Many thanks for the above info.

 

I Managed to get the carb completely apart now.  Those balls are brass, so one was only stuck because of verdigrises or something. When I got it apart, it appeared fairly clean after my last effort. It appears the inlet from the float bowl is above the dashpot piston and so the check balls must be there to stop the dashpot from moving up too quickly as they must check

[ or restrict ] the flow of fuel back to the lower carb area. They then maybe allow the dashpot to fall quicker, by allowing free movement of the fuel below the piston, to rise through the openings to the chamber above.  If those check balls were not there [ ie closed off, the dashpot would have a hell of a job rising. The fuel below it would probably cause an anti hydraulic lock when rising and a hydraulic lock when falling. ]

 

I had originally thought there was a lot of carbon buildup in the throat of the carb, but found it was just rough casting of the body covered with a black film of carbon.

 

I'm probably overthinking this, but maybe the balls are not supposed to seal perfectly so that they can allow the piston to rise. This carb is vaguely similar to an S U but definitely not the same.

 

Note:- I made a tool to hold the piston while undoing the top off the dashpot.

 

Not sure I have found enough or understand enough to explain why I have over fueling.

[nat]

     The dashpot and it's check balls only serve to "lift" some fuel as the metering valve head rises.  If the balls were removed the carburetor would function in all respects other than bogging, (for lack of fuel), upon acceleration.

     With the fuel shut off between the vacuum tank and carb, the only way fuel could flood the engine, (as you described), is through the vacuum line between the engine and vacuum tank.  

   

[nat]

    Troubleshooting is a process of elimination.  Fill the vacuum tank and disconnect the vacuum line, or gravity feed the carb to rule the vacuum tank in or out.

 

[nearchoclatetown]

I think the balls are bronze, available from Mc Master Carr.

[Mark Gregush]

If the float needle valve is not seated/sealing correctly, you can get the same results, re flooding. 

[carbking]

The brass balls lift from their seats when the the engine is in deceleration, allowing fuel to flow from the lower dashpot chamber to the upper dashpot chamber, thus allowing the dashpot to fall, thus reducing the fuel being delivered to the aspirator valve.

 

The presence (or absence) of the valves will NOT cause flooding.

 

GUESSING (I have never tried this, and see no reason to do so) that removing the balls would cause the engine to stall if it were attempted to be accelerated past an idle.

 

Jon

[nat]

Cutdown;

     If you haven't done so already, check the condenser.  

     Start with the dustributor cap off, points closed and with the ignition on open the points with something non condutive.  The coil should produce a blue spark that will jump more than 1/4".  Check the spark right off the coil terminal and through the coil and spark plug wires.  With the cap and rotor in place, take the plugs out, connect the wires and crank it over to witness a good spark at each plug.   I would get rid of  suppression wires even if they were brand new.

     If you get a good spark every time the points are opened. the condenser is probably good.  

     A condenser can be tested with an analog ohm meter.  Isolate the condenser from the coil and ground.  Place meter leads on the condenser leads, reverse the leads while watching the meter. The needle should jump and return to zero every time the leads are reversed.

     That may not be your problem but you can mostly rule out spark problems if it passes those tests.

     With spark, fuel and compression it should run even if those aren't all up to snuff.

Edited February 9, 2023 by nat
Forceps at birth (see edit history)

[cutdown]

My Mag wasn't up to the job so I sent it away for rebuilding. In the mean time, someone suggested I fit a distributor. I obtained a reasonably priced new distributor and coil, and set about making an adaptor to fit it where the mag was. [ this was because the mag repairer said he could not start the mag repair till Feb and may not be finished for another 8 weeks ].

 

Job well done but the problem was to make 2 spark plugs fire together from one coil. Needles to say, not such a good idea. [ more work required to sort that out. ]

 

Carb is ready to go back on, with a blanked off vacuum port, and we will see if it vacuum sucking extra fuel through is causing the over fueling.  Carb is not flooding due to a bad needle and seat. Its been too wet to test the vehicle as listed below.

 

NZ was hit by a tropical cyclone last Sunday, and there has been plenty of damage around the North Island, due to high winds and rain [ I am going on a motorcycle rally in the south island starting tomorrow, so preparing for such ] . It was pissing rain all the way back form Paeroa where I had been at a band competition on the Saturday. Kerikeri hasn't been hit so hard but heaps of rain and some high wind but nothing like the Wahine storm in '78.

 

The man doing the mag has got it mostly sorted and is going on the rewinding machine as this is written, Might be ready this coming weekend, and our rally just happens to be close by, so going to see the progress. [ I mentioned to him on Friday 3rd Feb that I was desperate to get this bloody Dodge running ]

 

No work has been done on the car over the last week.

[MrLiken]

Cutdown, any update on this?

[cutdown]

All going well since the refurbished mag was installed and the carb thoroughly cleaned. [ I was busy writing up about the work on the car in other threads, to realize I had not finalized this thread. ]

Working on perfecting the brakes after finding one drum was only 30-50 thou thick. Obtained a replacement that was very rusty and took some time to clean up. Still a work in progress but getting close.

Current job is repairing hood bows and sorting out the remanufacture of the hood [ soft top to those from the States ] The hood had been made from the original Touring hood, but never was able to fold down without covering the seat. No way you could drive the car with the hood down like that. I have reworked the front "irons", to allow it to fold back. I have to do this because or the recommendation to keep the hood up at all times to prevent shrinkage, but it needs to be fold down to get into our garage. Only 2 inches of clearance between top of screen to the tilting door when its up.

 

The last hurdle to finishing the job is that I live over 90 kms away from the testing station the tests vehicles prior to registration when they haven't been on the road in NZ for such a long time. Problem for me here is that the inspector is required to see the car and it's production numbers before he can get permission from LTSA to check the car. I am supposed to trailer the car down there and back just so he can check the numbers. That really is an insult to my integrity. Why would I lie about the numbers if  seriously want to get the vehicle registered for our roads.

 That's bureaucratic nonsense at its worst. 

 

By the way, the over fueling problem was related to under ignition problems. Once the mag was fixed there was no more over fueling problem.

 

Just now, I fixed the problem with the right hand door easily lifting off its hinges.  I measure there was 1/4 gap between the top of the top hinge and that restricting bracket, then cut a piece of 1/4 inch rubber sheet, jammed it in above the hinge then refitted the inner cover. That's  All fixed now.

Edited July 1, 2023 by cutdown
spelling etc (see edit history)