1948 cub

[nelly48]

Hello All,
newbe here, was handed down the old family Farmall from grandfather. According to him and serial on the data plate its a 48 cub which his father bought brand new from the dealer. Hasn't been running in about ten years has been stored in the barn. When it was running I was told it would stall out and seemed low on power. Dug into it during the weekend, before it was stored they replaced distributor cap and points, wires and three of four plugs, plus an oil and filter change, and all of the replaced parts still look brand new. However the fourth plug was filthy to the point that there was no gap whatsoever. Carburetor looks good cleaned it all up nice and drained oil no metal chips were found which is a plus. But there does seem to be some dirt and stuff on top of the pistons when I looked thru the spark plug sockets.

Which brings up a few questions.
what is the best way to clean the dirt out of the cylinders?
Would a dirty plug be the route cause of the problem or just the beginning?

[staninlowerAL]

Welcome to the Forum and congratulations on having the "family" cub. What you see on the pistons is likely a carbon buildup as your discription of the 4th sparkplug indicates and might be oil from worn rings. A thorough cleaning would require removing the head at which time you could check the condition of the valves and determine if further work needs to be done. If it were mine, I would prime the oil pump, remove the valve cover plate behind the carb and check/lube the tappets while turning the engine with a hand crank, making sure all are moving properly then adjust the valves for proper clearance. Next check the fuel system for a clean system, check the ignition for a good spark at the plugs. A good dose of SEAFOAM in the fuel and sprayed into the cylinders will help remove the carbon buildup when you get it running. See if it will start and when you get it running, observe the oil pressure and go from there to deal with whatever you find needs attention. A 1948 will probably be a mag ignition system. Check the links at the top of this page for manuals which will provide information and answers to the many questions that you will have. Good Luck and post how things develop. Stan

[tst]

welcome to the forum, sounds like you have a nice family memory, I am no far away from you myself right by Poughkeepsie, I would get it fired up first and do not worry to much about the dirt on the pistons, once running you can look the tractor over and drive it around to get a better idea what it needs
good luck Tim

[Stanton]

Congrats on the family Cub and welcome to the forum! Great story.

[Bigdog]

The fouled plug is not the cause of your problem. It is a result of your problem. The plug is fouling either from weak spark or most likely oil in the combustion chamber due to worn rings. Before you do anything else, run a compression test. It will give you some idea of the condition of the rings, valves etc. Run a dry and a wet test both and compare the results. Low compression and oil burning are causing your carbon fouling on the plugs.

[PVF1799]

Welcome - You've come to the right place. Check out the link in my signature to see what the help on this forum can do for you.

Also - we love pictures.

[Rick Spivey]

You need to prime the oil pump before you crank it. Do a search, you'll find descriptions and pictures.

[nelly48]

Thank you all for the help. Got cylinders all cleaned out, fuel system cleaned, and good news is she turns over without a hitch. But not getting spark to plugs. Wires are good, plugs new, and cap,rotor,and capacitor are new. Could it be the coil?

[staninlowerAL]

Mag or Battery/Distributor ignition system? Stan
EDIT: The diagnostic approach is completely different for each system.

[nelly48]

Hey all update on old nelly,she is up and running. Got old wood brothers mower deck attached and mowed field over the weekend. Not a hundred percent yet,has axle oil leak around brake housing on right side I am waiting on seal for, and an electrical gremlin that sucks the battery dry overnight. Does seem to be a little low on power yet.

[Bob McCarty]

Glad to hear you got it running. If the transmission is overfull from condensation, it will leak out the seals. You might want to remove the tranny cover and see if it looks like you have a milkshake in there. If so, it needs to be drained, cleaned, and refilled with 3 1/2 pints of gear oil. As suggested before,for the low power, you may want to check compression and see if rings or valves need attention. Running Seafoam in the oil and gas will help to clean out carbon buildup and may aid in getting some power back. I'm not the electrical guy to answer your battery question.

Bob

[staninlowerAL]

... an electrical gremlin that sucks the battery dry overnight. Does seem to be a little low on power yet.

I'm not the electrical guy to answer your battery question. Bob

I'm not the electrical guy either but with a wiring harness and electrical system that is 65 years old I would take a close look at possibility of a bare wire shorted to ground, cutout/vr contacts, etc. If you still have a mag without being converted to external coil, the engine should start with the hand crank without a battery in place. Stan

[Bigdog]

Electrical problems can be tough to pin down. It just takes a little time and logical elimination to find the problem. It could be a sticking regulator or cut-out or many other things. Does the ammeter show a charge condition when running? Does it show discharge when not running? Be patient, we can figure it out.

As far as the low power issue - there is not a lot of power to start with but with the design of the engine and it's torque you can do a lot. I suspect you will notice a slight increase in power after using the cub for a while. The engine components will re-seat with use and it should pep up some. You can help it by making sure point spacing and timing are as close as possible. I would also check and adjust valve lash as that can help a lot.