Well, I finally figured out the reason for my problem. After I took the carb apart and verified all of the passages were open, I looked at the gasket between the carb bowl and the throat, and realized the gasket did not cover the center section, which separates the idle from the high speed circuits of the carb. I just used the old gasket as the guide when I make the new one. Anyway, I remade the gasket, and the motor runs great. It starts and idles, and runs very well at governed speed.

Thanks for all the good advice, I really appreciate it. Now I've got to figure out why the diesel engine doesn't start.

54D2

That gasket is basically 2 concentric rings. That is good detective work to figure out that the middle on was missing.

I did a search and it looks like there are some good ideas here.I just got my pony back together after a cam gear issue.I checked all the air and oil passages,air filter,air horn and oil return passages before I reassembled the pony.I had to purchase a new float bowl as the old bowl mounting threads were all but stripped out.Got it all back together and tried to fire it off after setting the idle and main jet up as per this thread.All the passages are clear and the float is set properly and is not saturated as I tested it in gas for one half hour before assembly,the needle and seat are working great.Now it will only run with the throttle and choke in the off position and then it runs at a low idle and very rich (black smoke).The only way I can get it to rev up and stop the black smoke is to turn the gas petcock almost to the off position,basically using it as a main jet,until it revs up and runs hard enough to start the big engine.I have never put so much work into something and then have a total POS when I was done.I have tried every adjustment mentioned,checked everything many times over and it still runs the same as mentioned.Any suggestions as to what I am doing wrong or may have missed will be appreciated,Don.
1952 D4

I can understand your pain and discouragement. The only thing I can suggest is to go throught the carb and make sure all gaskets are in place and separating the idle and high speed circuits Also, verify the needle valve seats properly, and the adjusting screws aren't damaged which could result in an improper adjustment.

It would be worthwhile to review a schematic of the carb and track the path of the fuel path on both the idle and high speed circuit. You can then verify the carb's fuel circuits are open.

Good luck

54D2

Hi Team,
here are 2 scans from the relevant SRB showing the fuel passage layout.

As mentioned by ccjersey, NOTE the action of the main jet adjust screw, item (4) in the No1 scan, as it is reverse in its action, ie, screw IN to Richen, OUT to Lean of the mixture.
Usually crud accumulates at the idle discharge port and blocks the idle mix-- Item 6 scan 2.
This is a delicate plug with a grouve on the body and a flat on one edge to allow fuel flow, Note there is a vertical ridge on the outer face of the plug to orientate it in the passage, I cannot recall the flat's orientation, but you will need to check it before removing, note also that the inner end of the plug is flush with the throttle plate bore, sometimes needs a couple of tries to get it flush, DO NOT attempt to push it back in from the inside or the jet/plug will be kaput. Press it through and start over.

CAUTION only press the plug in from the outside as the area with the flat is very delicate.

Hope this helps.
Cheers,
Eddie B.

Great pictures edb,this is great information I did not have.I am going out today and pull the carb again and check the idle discharge port, hope that is what the problem is.Another idea of mine would be the lack of a washer under the main jet. My main jet adjuster is the other type,I do not know which is the newer setup,it screws straight down thru the top of the float bowl top.If there was a washer there at one time and not now that would make it impossible to shut down(or lean out) that adjustment.I am going to try and figure out if the needle is seating in the main jet or not.Does this sound like it would happen?Also I put a new float bowl gasket on and it is twice as thick as the old one,could this have made the problem worse? Thanks to everyone for your help. Don

That style is used on some of the other ponies where the fuel tank doesn't interfere with access. Since it is a replacement bowl, I wonder if it is the one off the D6 pony carb and if it is compatable or if the jets etc are too big by far.

Hi Don,
it is concieveable that a combination of the missing jet washer and thicker cover gasket are preventing the needle from fully controling the fuel mix, ability to lean out.
Also the thicker cover gasket will artificially raise the fuel (float) level in the bowl and may be flooding the carby by this action.
I believe the early carbs had the vertical main mix screw. It appears this screw has hole drilled in the side of the hollow jet shank and the action of screwing the jet screw in and out effectively alters the area of the hole exposed above the jet body thus altering the mix. It does not have a taper and therefore does not seat in the jet body to control the mix.
Scans below of early J series D2 pony carby may help.
Cheers,
Eddie B

Thanks for the pics edb,that looks exactly like my carb. I was looking at the photos you posted and all of the sudden I did not remember changing the compensator jet over to the new float bowl.I don't throw anything like that away so I got it out of the box and sure enough there it was under all that crud in the bottom of the float bowl.Seems like my problems have been mostly self inflicted but anyway I still had to shim up the main jet about 3/64" to get things to work right.The pony starts right up and idles fine but still runs a little rough at speed and the big engine starts easily once I get the pony clutch to engage.Does anyone know where to get new compression release valves, the ones on the bottom of the heads are turning to the open position all by themselves.Thanks again for all the help,I don't know if I would have ever tried this pony repair without the information made available to me at ACMOC. Don

I use the McMaster #4793K64 drain cocks.