Farmall Cub

Well I re-did a tune up and am having the same problem. I'm thinking I may have to open the engine up again and see if if I may have missed something or did something wrong.

About all I can think of in basic engine assembly that might cause this is mis-timing the cam shaft. I'm not even sure that could cause it. You can check cam timing without disassembly.

Get somebody local to look it over first hand before you start tearing it all apart.

The rotor turns clockwise and cylinders are numbered from the radiator.

Ok so I got the carburetor fixed and the smoke has turned more of I guess a blueish. It smells like an old diesel engine. And she isn't running smooth. Could the tractor shop given me the wrong piston rings? That is the only thing I can think of now that the carb is working right and the smoke is no longer black and smelling like gas.

So forgive me if you think I don't sound like much of a mechanic but I am still learning about the old vintage stuff. My training is on more advanced things like attack hellicopters

So what was done to the block to prepare it for a rebuild? Was it bored oversize? Were the cylinders honed? By description it sounds like new rings were put in old worn bores.....

Megoto wrote:Ok so I got the carburetor fixed and the smoke has turned more of I guess a blueish. It smells like an old diesel engine. And she isn't running smooth. Could the tractor shop given me the wrong piston rings? That is the only thing I can think of now that the carb is working right and the smoke is no longer black and smelling like gas.

Is there a chance, any chance that you (or someone else) put 2 stroke mixed gas in this?

Or maybe some diesel fuel or kerosene?

If there is a chance, drain it out and put some fresh gas in the tank. If the gas is old, drain it out and use some fresh stuff!

Just a thought!
Good luck!

Cylinders were honed. There was no visible damage to the walls and no corrosion. Did I miss something?

No chance don't have any Diesel machines and there is no 2 stroke oil or mix in my shop.

Did you measure the bore to see how worn it was ?

tst wrote:Did you measure the bore to see how worn it was ?

Measure the bores in multiple spots of each bore?

And if you reused the pistons they whould need to have been measured (multiple places) to see if they are within IH specs, especially the skirt area!

I measured where I could on the bore and I didn't measure the pistons so I guess I will be pulling them back out. Learning curve sucks. I will be getting a better manual as well. How do you measure inside the bore? I've never had to measure anything like that. I have a set of calipers and a machinists ruler but I am not able to get accurate measurements of anything deeper than the calipers can reach.

Megoto wrote: How do you measure inside the bore? I've never had to measure anything like that.

The best tool is a dial bore gauge, but they are expensive and very limited use! Chances are only a engine shop will have one!

The ideal "home" shop use is a quality telescoping gauge and micrometer from a company like Starrett!

A inside micrometer works too, but they can be cumbersome in a small bore!

Problem is even the finest of measuring tools takes some practice and "feel" to get precision measurments with!

Megoto wrote:I have a set of calipers and a machinists ruler but I am not able to get accurate measurements of anything deeper than the calipers can reach.

Calipers are not for precise precision work! Even with a quality set a person can squeeze it enough for a +/- .004, or have it cocked, off center, not square, etc!

Lol! Fyi..... Machinists dont use rulers, Kids in school do..... Machinists use steel scales!

Do you know a machinist, tool & die maker or mold maker? They would be your first "go to" for help on this matter!

No I don't. So if I can do it myself I would much prefer that. I can make pretty much anything as long as I have a design and I can get the telescoping guage and calliper. So any advice is greatly appreciated. Just need to keep the brain busy

Megoto wrote: So if I can do it myself I would much prefer that. I can make pretty much anything as long as I have a design and I can get the telescoping guage and calliper. So any advice is greatly appreciated.

Once you have the measuring tools, copy or print out the proper specifications page (that is where the minimum and maximum specs will be) from a IH Cub service manual, whether you have a hard copy at home or need to print one off from the pdf manuals section here at farmallcub.com!

On the printed or copied page you can write all your dimensions from each measurement!



*You might do a zip code search and see if there is a member close by your area that could help you out!*

Goid luck, I hope you get it figured out soon!

Me too, thanks for the help and I'll keep y'all posted.