help troubleshooting why my '52 Farmall Super M just quit

Until it stopped all-of-a-sudden, my 1952 Farmall Super M purred like a Swiss watch; it started first time, every time - no matter how cold it was. When it stopped, I tried to re-start it - whereupon it "spit" gas out of the intake manifold. Thinking the carbeurator shot craps, I rebuilt it - only to have the same thing happen. Someone told me such a "sympton" might indicate a broken valve spring or a stuck valve stem; have any of you (who really know the Super M engine) heard of this...or do you have any trouble shooting suggestions? If it try to start it by pulling the tractor, do I risk breaking (or bending) something significant? Help; I"m all ears!

Open the fuel lever at the strainer bowl. Then remove the low level plug on bottom of carb. Fuel should run out in a few seconds. If it keeps on draining it is a needle valve stuck open. This could be the result of a float that has a hole in it and is full of fuel, or badly set float. You can inspect the float, and set it by removing just the bottom bowl.
If you are blowing liquid gas out of the manifold you have to solve the excess fuel problem first. I don't think your M would go from a purring kitten to a non runner because of a sudden valve train problem.

Gordo

Do you have a live hyd. pump on this tractor and if so were you using it when this happened ???? sure sounds like she sheared the cam key . Just a thought .

Possible cam key or broken cam gear. I would not pull it. Set the #1 piston on TDC (whoshes air out on compression stroke) then look at the distributor rotor it should point to the #1 spark plug (usually at the 2o O'clock position) If it is not, the gear might be broken. JimN

You didn't say if you still have a spark. Could be a wire come loose or something grounded out.

thanks for your reply. what you suggested is what i originally thought...so i put in a new carbeurator kit (needle, gaskets, float, etc) - so when it acted the same way again, i felt that wasn't the problem...becuase if it WAS a bad needle or float, replacements should cure the problem.

Yes it does have a live hydraulic pump...as it has been retrofitted with an after market 3-pt hitch.

For someone (like me) who isn't an engine expert, two questions, please:
1) would this 'cam key' be part of the main cam mechanism, or some 'cam' associated with the hydraulic pump? - and
2) if it IS the cam key (on the main cam mechamism) repairing same would require tearing apart the engine, right?

Sorry for not knowing; I'm just not that knowledgable about engine operations.

Thanks for asking; sorry for not saying if it has spark. I thought that might be the problem...so I checked and yes, I do have spark.

Have you checked the inside of the distributor cap for a crack or other trouble [rotor problem]??
If everything checks out, I'd remove the valve cover & see if things are in good shape. Watch the valve action to confirm if what Jim has suggested--that the cam isn't turning in time with the crankshaft.

Tr Vet also---sorry TV

Sounds like the camshaft isn't turning for what ever reason. Stripped timing gear or broken key like the other guy said. take the distributer cap off and turn the engine over and see if the shaft in the dist. turns or not, if it doesn't turn, cam shaft is not turning. good luck

The front of the engine has a set of gears that drive(from the crankshaft to the cam shaft, then to the side where the hydraulic pump (If it has a live hydraulic system, meaning that it will raise the bucket with the clutch pushed in) and distributor are located The cam shaft is driven by a keyway that locates the lobes in relation to the pistons. If the system wears the gear and keyway, it can fail with backfiring as a result.
Other causes can also happen in the distributor system. Do a compression check.
Buy or borrow a compression tester (make sure it fits the larger size spark plugs.
Open the throttle all the way open, spark plugs all out, Ignition off, and fuel turned off. Crank the engine for at least 5 fill compression cycles. and read the gauge. It should be more than 120PSI. do the remainder, and tell us what the reading is. We will go from there. JimN

YEP , more then likely you were using the three point when this happened but maybe not . Yes there is a key in the camshaft that the drive gear fits over . To fix this the ft. of the tractor MUST come off . Now this is not a hard job IF all the bolts come out . Now the down side of this job is that you will need a hoist or cherry picker as the ft. bolster is a wee bit heavy . The steering shaft should come out but it can be done with out removing it all the way . It helps to loosen the frame rails that way the ft cover will come out a lot easier . One thing is to make sure that you have the tractor well blocked under the bell housing and both wheel brakes set and chocked . A good gear puller and the usual hand tools will get the job done . while setting here thinking about this before ya go thru pulling the ft off first pull the hyd. pump and dist. off first and check the key in the hyd. pump drive first . I have had to replace two on a friend S/MTA as it sheared that key twice a year apart last time i installed a hardened key so the next time it will be the cam key or the gear when it goes the next time. SO look at the drive end of the pump before ya start getting real dirty. Here again you will need a puller .

Also read my reply higher up the page. Similar content, different test. JimN

Before you go too deep looking for a broken cam key, check the small gear in the distribetor. If these gears are wore out they climb over & get out of time.

If you have spark the cam is turning.

Should is the key word,I rebuilt the carb on my smta same engine and it took at least 5 or 6 tries to get the float to stop rubbinng against the bowl.There is not much clearance there,if the float sticks you will have gas in the manifold.Also check and be sure that you have the exact float as your old one do not trust the parts guy.I have had many overhaul kits that contained the wrong parts