Case S exhaust manifold leak problem

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Hello all,

I have a CASE S which I took the head off, lapped the valves and assembled the head and exhaust back on. Now, the tractor will only start when the choke is pulled out and there's exhaust coming from the exhaust maifold and a slight gas leak below one of the intake mainifold ports where it connects to the engine block. I had to clean all the heavy dirt, grease, and oil off the head where the exhaust manifold and muffler is positioned, maybe that gunk helped seal the manifold.

Should I use gasket cement. Also what is the proper setting for a Case S carburetor? Many thanks!!!

Rian, Ontario, Canada
 

Should have 2 ferrules on the center inlet ports don't sound like that's your problem through. Do You have new gaskets on it. Mine had the OEM gaskets plus an additional gasket that I found was from a model T ford 3.95 first pic below the other is a copper gasket at 12. 95

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These 2 pics above are from Archives this is how I found out what mine had on it. Below is the original write up

I had the same problem when I replaced the head on an SO. I used Model T Ford manifold gaskets. They align pretty well but need some slight trimming and an increase in the intake port holes from 1 1/4" to 1 3/8". Part number is T-3063-X for the flat asbestos gaskets

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FERRULE
 

Gees sure wish they still had the edit function I don't think any sealant will help the exhaust leak remove and replace gaskets with new ones or add additional T gaskets
Best of luck Byron
 
(reply to post at 21:12:44 09/14/16)
Since you didn't say what year tractor or what carb you had this is from archives

Here are the settings for the model SC Zenith 9667A (05771AB) carburetor. Since this question comes up from time to time- I thought I'd type this info in so it can be referenced in the archives. Hope this helps.

(FROM THE CASE MODEL 'S' SERIES OPERATOR'S MANUAL) Float level:
1-5/32" (+/- 3/64") from surface of upper casting to bottom of float in closed position (turned upside down)

Idling adjustment:
Adjustment for idle speed and idle mixture can best be made together and should be made with the engine warm. The throttle level on the seat mounting bracket should be all the way forward before making the adjustment. The idling speed screw 1 (Fig. 12) (which is the screw on the side of the choke butterfly) should be adjusted so that the engine will idle fast enough to prevent stalling. Then turn the idling jet adjusting screw 1, Fig. 12 (which is the top screw with the spring) in or out until the engine runs smoothly.

A good starting point for the adjustment is ONE FULL TURN from the idling needle valve seat because the correct setting is usually between 3/4 and 1-1/4 turns open.

Main jet adjustment:
This adjustment should be made when the engine is warm and working under load because it exerts the greatest influence under those conditions. Turning the main jet 3, Fig. 12 (the T-handle jet on the lower bowl) inward provides a leaner mixture, while turning outward produces a richer mixture.

Turn the valve inward until the engine starts to miss or power falls off. Then turn outward until the proper operation is secured- about 1/8 of a turn is usually sufficient. This setting will assure maximum fuel economy with very nearly maximum power.

If the engine will not run with the original setting, make and approximate setting as follows: Turn the main jet valve inward until the needle just seats. Use great care not to force the point against the seat as this may ruin the seat. Next turn the valve outward TWO FULL TURNS. This setting is sufficiently close so that the engine can be operated until final adjustment is made.
 
did you check the manifold for straightness? sounds like it is warped, the only fix is to plane the manifold, ferrules have nothing with sealing the manifold and carb adjustment will have minimal effect on starting, more likely you are sucking air around the intake ports, which reduces manifold vacuum and leans out the engine which requires the choke to be used more, on metal gaskets I usually apply a thin layer of hi-temp silicone around the intake ports though the gasket should seal it, you did reset the valves didn't you? also make sure you get all of that damned lapping compound out of the head, it and honing grit are the two worst things you can put into an engine
 
Its possible the ferrules are holding the manifold out by sitting on a build up of rust carbon or debris gunk that might explain the intake leak but not the exhaust leak. Ask me how I know that. The manifold is only maybe 1/4 inch thick very small area to seal. If installed correctly the ferrules will have no direct effect on the sealing of intake leaks they are not a close tolerance fit and I Never meant to insinuate they were. Because you didn't say it was leaking before leads me to believe there's something wrong with your installation. However as others have said you may want to check the straightness of the sealing area if you haven't done that as of yet.
Best of luck with it Byron
 
The starting problem is almost certainly due to the intake manifold leak. I wouldn't mess with the carb until you get that dealt with.... I also wouldn't advise using any type of sealer on the exhaust manifold. If the manifolds weren't leaking before you worked on it, you can safely assume you made some kind of mistake during reassembly. I'd take them back off and have a good look at everything. Be sure you tighten your bolts down gently and evenly.
 

Thanks for all this help. Yes, I think I might switched the gaskets without knowing and they maybe upside down for all I know, there is no way to tell.
 

Hello all, thanks for the advice. The copper manifold sealant works very well. But now the tractor exhaust is smoking (black shades) backfiring a bit and coughing. I think its getting too rich of a mixture. But now my dad says that he can't even crank up because it feels like there's too much compression? I set the valves at 010. with a slight fraction of play. Could the valve rockers be incorrectly set? Also, I realized that some of the valve rods had a very slight bend or curve to them, can that cause incorrect valve setting?

Still have problems... :(
 
(quoted from post at 15:54:28 09/26/16)
Hello all, thanks for the advice. The copper manifold sealant works very well. But now the tractor exhaust is smoking (black shades) backfiring a bit and coughing. I think its getting too rich of a mixture. But now my dad says that he can't even crank up because it feels like there's too much compression? I set the valves at 010. with a slight fraction of play. Could the valve rockers be incorrectly set? Also, I realized that some of the valve rods had a very slight bend or curve to them, can that cause incorrect valve setting?

Still have problems... :(

First if you used the model T copper gaskets the holes should be trimmed to match the hole diameter in the head as noted above if you didn't do that Id fix that first. Then I would pull the plugs out and the valve cover off hopefully there's no water in the cylinders. Make sure the rockers arms are all in place push rods are seated in the lifters and the rocker arms. Sounds like maybe an exhaust valve is not opening, Now if everything checks out Turn it over by hand and look in the spark plug holes you can see if the valves are opening and closing. If its still hard to turn something wrong with the valve train somewhere maybe a bent valve bad rocker scared lifter hole since you just lapped the valves I don't think you could miss a bent valve. The fact you have a couple of bent push rods already tells me something is going on there.
Last but not least Id wait and get an Opinion from one of the TRACTOR EXPERTS. Trust me I'm NO EXPERT. Since no one answered your post I thought I would give you something to think about.
Best of luck Byron
 

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