Trouble with my 1949 Cub

[WildFarmall]

Last year I spent a lot of money on having my 1949 Cub engine overhauled. I took it to a Case/International dealer that was located @ 100 miles away because I wanted someone experienced. I really liked the service manager, and he spent a lot of time with several calls explaining what they were doing. The engine cylinders were bored by an outside machine shop and new rings were put in, among other things. When I got the tractor back last summer there were several things wrong, including that the timing was not set properly, which the service manager readily admitted was their fault. I hand adjusted the timing and it ran better but by the end of the summer the tractor had lost power and ran poorly. i called the manager and he agreed to take the tractor back and work on it. He adjusted the timing with a timing light, adjusted the fuel mixture, changed the oil, changed the plugs to "a hotter type", and did some other things. I might note that the oil pressure reads good with the guage showing the needle all the way to the right. The plugs this past summer had some gas/oil on the firing gaps. The manager seemed to think that was caused by having too much gas being fed into the carburetor by having the set screw too far out.
When I got the tractor back last week it ran great but now it is running a little rough. The motor does not seem to be as smooth, and I see a little blue smoke every now and then in the exhaust. I have not checked the plugs but will do so tomorrow. I checked the oil level, and it reads about 1/2" to 1/4" above the full line on the dipstick. Is this too much and could that be the problem? Any suggestions?













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[staninlowerAL]

Just a comment about the fuel mix adjustments, etc. The OEM carburetor on a Cub has a fixed jet both idle and high speed. The only adjustment is the air volume. Is your carburetor a IH or Zenith? Early cubs used the IH and later switched to Zenith, part of the attempt to boost the hp. Can't tell the year/SN without looking it up but either one should work fine. You will probably get more comments later.

[indy61]

I checked the oil level, and it reads about 1/2" to 1/4" above the full line on the dipstick. Is this too much and could that be the problem?

The Touch control pump could be leaking fluid into the crankcase. Fairly common problem. Simple fix, usually, if that's the problem.

[Glen]

Hi,
If someone simply put in a little too much motor oil in the engine, I don't think it would cause any problem.
The Touch Control fluid is thin, if the Touch Control fluid leaks at the pump seal, and the fluid goes into the engine, that thins down the motor oil, then the engine can smoke.

Check the Touch Control fluid at the filler plug on the left side of the Touch Control.
The arms have to be in the rear or down position to check the fluid.
The fluid should be up to the filler plug hole.
If the fluid is low, someone might not have put in enough, or the pump seal could be leaking.

If the engine is running too rich, the carburetor float level might be too high, and need setting.
People on here have said that their carburetors wouldn't work right until they set the float level exactly.

You didn't say if the dealer or you have cleaned the air cleaner.
It should have clean light motor oil in the oil cup.
The air cleaner might need removing and the upper part of it washed out with kerosene, if the material in it is dirty.
If it is plugged too much, that can make the carb mix too rich.
The 1949 Cub owner's manual tells how to clean it.

If you have an original style oil pressure gauge, which I think is about a 40 lb gauge, the pointer shouldn't be all the way to the right all the time, that is too much oil pressure.
The oil gauge might not be right, or the oil pressure regulator might have a problem.

A 1949 Cub came with an IH carburetor. IH changed Cubs to Zenith carbs during 1975, some people put them on older Cubs.
Below are pics from TM Tractor of the 2 carbs.
The 1st pic is the IH carb.
The 2nd pic is the Zenith carb.

[WildFarmall]

Thanks so much Glen. I have been out of town for @ 2 weeks and have not been able to address this. Getting back to work on the tractor today.
I am pretty certain that I have the carb that is on top (the first picture).
I bought a rebuild kit for the hydraulic pump from TM Tractor and plan to do that today. I drained the hydraulic fluid, oil, and installed a new filter.
I did notice that the oil pressure was reading high on my pressure guage. Hopefully there is not a problem with the oil pressure regulator. I have no idea where that is or how to fix.
I will check the air cleaner but do not think that is the problem.
I appreciate your knowledge.

[Eugene]

How many hours have you operated the tractor since the engine overhaul? Type of work? How long are the work periods?

I would start with a compression test, cold engine, dry only. Basically, this is to confirm that engine is good mechanical condition. If dry test is low then wet test.

Engine running poorly. I would suspect ignition related problem(s).

High oil pressure. Wait on this until the running poorly problem(s) is/are solved.

If you can not do the tests yourself, have someone other than the IH dealer do the work.

[ricky racer]

Regarding the over fill engine oil level, try just turning the dipstick over and rechecking the level again. Those lipsticks aren't always straight.

[inairam]

I have had problems with OEM IH/CASE ignition parts. I started using NAPA for points and condensers rotor and cap.

Distributor Cap Part # ECH IH350
Distributor Condenser Part # ECH IH200
Contact Set (Points) - Magneto/distributor - Ag Part # ECH CS1600
Distributor Rotor Part # ECH IH300

Also what gas do you use? Does it have ethanol? Ethanol absorbs moisture. Your zip code looks to be right on the coast with a lot of humidity. I use STA-BIL 360 Marine Ethanol Treatment and Fuel Stabilizer in my gas. It is blue not the red version. It may help reduce the moisture in the gas which would cause some of these issues.

[WildFarmall]

Today I replaced the seals in the hydraulic pump, refilled the system with prescribed hydraulic fluid, changed the oil and oil filter, and then started the tractor.
The oil pressure guage showed high pressure with the needle all the way to the far right as it could go. Additionally, oil began to seep out of the top of the oil filter casing. I checked one plug and it was black with soot. I am thinking that the oil pressure is so high that it is pushing oil by the piston rings and fouling the plugs.
When I sent my tractor last year to the Case/International Dealer to have the pistons bored and new rings and pistons installed the oil pressure was fine. When I got it back the pressure was real high with the needle all the way to the right. When I told the service manager about this he said that was typical of a new engine. It now seems likely that the oil pressure regulator valve is malfunctioning. Should this have been checked when doing an engine overhaul?
I think that they should have known that high oil pressure would cause problems. It appears that to check or service the Pressure Regulator Valve the engine must be removed from the tractor. Is there any other way to check or service the PRV?
On another issue someone I talked to warned me that certain types of rings do not work well with Farmall Cubs. I will look for my parts list for the overhaul but I am hoping that this is not a issue as well.

[Don McCombs]

Can you post a photo of the face of your oil pressure gauge?

[Glen]

Hi,
I would do what Eugene said first, the oil pressure isn't the most important thing.
I don't think that the high oil pressure would cause problems with how the engine runs.

The float level in the carburetor may be too high, causing the engine to run rich.
Sometimes if the float level is too high, the carb drips on the ground when the Cub is sitting.

Below is a page from the 1950 Cub owner's manual, showing the style of oil gauge the Cub came with.

http://farmallcub.com/rudi_cub/www.clea ... e%2005.jpg

It now seems likely that the oil pressure regulator valve is malfunctioning. Should this have been checked when doing an engine overhaul?

Yes, if they had the engine out of the Cub, and completely apart, they should have removed the oil pressure regulator.
Usually shops would put the engine block in a hot tank to clean it, that cleans all the internal oil passages, and the cooling system passages.

It appears that to check or service the Pressure Regulator Valve the engine must be removed from the tractor. Is there any other way to check or service the PRV?

No, you don't need to remove the engine to look at the oil pressure regulator. It is easy to get to.
It is behind the 6 sided plug, below the magneto, or Battery Ignition unit, whichever the Cub has.
It is where the upper bolt holding the front end on the Cub is.
Below is a pic from TM Tractor showing it.
The plug is the shiny 6 sided plug in the pic.
To remove it, you probably need to remove the bolt holding the front end on the Cub, then you can put a socket on the plug.
Do not remove the lower bolt holding the front end on the Cub.

Below are listings from TM Tractor showing the parts of the regulator, there are only 2 parts in the hole where the regulator is.
There is a spring, and the valve.
The spring should look like the spring in the listing.

The valve needs to be free sliding in the bore it fits in.
Sometimes the valve gets stuck in the bore. If it is stuck it needs freeing.
The valve has to be the right direction in the bore, the spring goes into the hole in the valve.

http://www.tmtractor.com/new/en/537fp.htm

http://www.tmtractor.com/new/en/671fp.htm

There is a gasket on the plug.

http://www.tmtractor.com/new/en/492fp.htm

[Jim Becker]

Excess oil pressure is one of the best problems to have. You can check the pressure regulator, as already described. I would probably try another gauge before doing anything else about the pressure. And I would deal with the other problems before worrying about the oil pressure.

[WildFarmall]

Thanks everyone. This is great help. I am pretty sure my oil pressure is too high as oil seeps out of the top of the oil container. I will buy a oil pressure guage to test my pressure and report back.
It is nice to know that the Oil Pressure Regulator can be accessed. I will look at this after I check the oil pressure. If this is the problem, I am hoping that I can free it easily. I assume that the spring is the regulator.
I have been on the phone with Ron at TM Tractor and he is a great help and resource. I buy all my parts there!

[Don McCombs]

Your problem with the oil leak at the filter may not be excess pressure. If you used one of the flimsy rubber gaskets when you changed the oil, it may not be seated properly. I stopped using that type gasket and went with a rigid paper gasket because of that issue. TM Tractor Parts has them.

[WildFarmall]

Thanks everyone.
Today I accessed and examined the Oil Pressure Regulator. It appears to be ok. I bought a new Oil Pressure Guage and will install and check that tomorrow.
I will try to seal the leak around the oil filter.
I also bought a piston compression gauge and will measure compression on each of the cylinders. I understand that the compression should be 100 or better.
After talking with Ron from TM Tractor it now seems like the plug fouling may be caused by the carb letting too much fuel into the cylinders. It may be that the jet opening on the carb is too big thereby bletting to much fuel into the cylinders. I paid to have the carb rebuilt but maybe the fuel jet is too big. This may cause the plugs to carbon up and foul because all the gas cannot be used. I have extra carb parts around so hopefully I have the right one.