Engine rebuild 1949 Cub.

[Flyboy]

I wasn't saying that the PDF wasn't good, my computer is old and has troubles with various things depending on the day of the week. I was merely saying I hadn't read it because I couldn't get it open.

I did some research on condensers and it sounds like a bad condenser would not prevent it from creating a spark. The points look good, but I am no expert. No pitting or erosion.

That leaves the coil and other associated parts under the body. I am going to buy a working mag so I can get it running, then try to repair my magneto and reinstall it on the tractor.

[Flyboy]

The TC37F manual downloads just fine. I just double-checked it. Try downloading it again as it is a lot easier to have a bookmarked pdf available for reference.[/quote]

I actually print everything. Nice to have a copy out with the project when you are working.

[Flyboy]

The tractor is running. It needs choke to keep it going. I disassembled it and split the top from the bottom, cleaned up everything as well as I could. Runs the same. The carb rebuild kit just arrived and I noticed in the schematic the the idle tube looks like it protrudes up from the bottom or down from the top of the casting. Mine is flush with both. So I suspect it is broken at the seam. I don't think I broke it when taking it apart, but it appears that it is broken.

Is it a replaceable part or do I need to start looking for an upper casting. My carb is the IH, not Zenith.

[bob in CT]

Get a left hand drill bit and drill it out. The thread is 4-48 and that tap drill size is #42. I would use something smaller, like a 44, and the stub should back right out with the drill bit leaving the threads untouched.

[danovercash]

BTDT, do not use an electric drill! Use a hand held tool to hold bit. With an electric drill you may wind with one too many holes in the carb. Cub will run without idle tube, yours was probably already broken off unless you find it in your work area. You may need to check choke linkage to make sure it is set right. Also you can remove the plug in the intake manifold to play with fuel/air mix and/or add propane to intake side of carb to see if too lean. Four different jet sizes were used.

[Flyboy]

When I split the carb, most of the ports were open and round. One each (upper/lower) was not smooth with the surface of the casting. After looking at the schematic of the carb, I went on line to find pictures and discovered that the photos showed a tube extending downward from the upper casting. Mine doesn't have that. The ports that are not even with the casting is where the idle tube should be, so it appears to have broken off at the split between upper ad lower casting. I have been in North Dakota trying to solve their problem with pheasant overpopulation, so I haven't been into the carb for over a week. I will remove it tomorrow and see if my memory serves me well. Thanks for the advice.

[staninlowerAL]

the photos showed a tube extending downward from the upper casting. Mine doesn't have that. The ports that are not even with the casting is where the idle tube should be, so it appears to have broken off at the split between upper ad lower casting.

That is where they usually break. The guys have you covered on R & R, the idle tube/jet is available but pricey if you get it from CASE IH. The lower half in the bowl part of the carb should just slip out, it's not fastened in any way. The last one I did, I soaked the upper tube orifice in penetrant (PB Blaster) and used a very small easy out to unscrew it from the top. If you do this, just be sure you don't apply too much force and break the easy out. As Bob in CT says:

Get a left hand drill bit and drill it out. The thread is 4-48 and that tap drill size is #42. I would use something smaller, like a 44, and the stub should back right out with the drill bit leaving the threads untouched.

Good Luck. If you need the help, Bob McCarty is one of the best around and somewhat close to you near Longmont. Stan

[Flyboy]

bob in CT: you say the threads are 4-48. Do I need to know that for some reason or is it to let me know that the drill bit should be smaller so I don't enlarge the bore? My assumption is that I want to hit it with PB Blaster and let sit, then use a left handed #44 to try to get it to come loose, without actually drilling to the depth of the threads. Do I have that right? If so, at what depth do the threads begin? I want to mark the bit so I don't go cutting into the threads.

I have to go into town to get a blower motor for my pellet stove. There is an OReilly's across the highway, so I will go try to find an easy out of the appropriate size to remove the idle tube. Ordered an idle tube from Steiner, so it is on the way today. Hopefully it will be here by Tuesday. I will try to get in touch with Bob McCarty sometime. It would be nice just to chat with him. What do people use to reduce file size of pictures so they can be posted? I have PhotoShop 5, but have only used it a time or two a couple years ago, so I have forgotten the little that I used to know. I am not asking for a Photoshop tutorial. I just want to know if there is an easier way to do it. If PhotoShop is the best way, I will go find a tutorial on Youtube.

[danovercash]

I would stay away from the easy out. Any left hand bit as long as smaller than hole should work. Thread size given because some with the resourses retread the broken pipe and reuse. Purchase a small hand mandrel ( I think that's the term) to use with bit. Worked great for me. Easy out will push out, you don't want that in soft metal. Not that hard, btdt. Threads start flush with edge of hole I think. Thinking I used a 1/16" LH bit to remove broken piece.

[Flyboy]

I would stay away from the easy out. Any left hand bit as long as smaller than hole should work. Thread size given because some with the resourses retread the token pipe and reuse. Purchase a small hand mandrel ( I think that's the term) to use with bit. Worked great for me. Easy will push out, you don't want that in soft metal. Not that hard, btdt.

Roger that. Thanks.

[danovercash]

See above edit. Got LH bits at northern tool. 1/16 thru 1/2 in metal index for not much money.

[Denny Clayton]

I would stay away from the easy out. Any left hand bit as long as smaller than hole should work. Thread size given because some with the resourses retread the broken pipe and reuse. Purchase a small hand mandrel ( I think that's the term) to use with bit. Worked great for me. Easy out will push out, you don't want that in soft metal. Not that hard, btdt. Threads start flush with edge of hole I think. Thinking I used a 1/16" LH bit to remove broken piece.

3/32" works just fine.

[danovercash]

Thanks Denny, that's what I probably used.

[staninlowerAL]

My assumption is that I want to hit it with PB Blaster and let sit, then use a left handed #44 to try to get it to come loose, without actually drilling to the depth of the threads. Do I have that right? If so, at what depth do the threads begin? I want to mark the bit so I don't go cutting into the threads.

The top half of the tube is about 1 1/2 inches long and the threads are about 3/8 inch on the extreme upper end of it so when you start the removal process work from the lower end (at the point where the two sections of the carb come together). This will give you about 1 inch of length to work with before you get to the threads. Stan

[bob in CT]

bob in CT: you say the threads are 4-48. Do I need to know that for some reason or is it to let me know that the drill bit should be smaller so I don't enlarge the bore? My assumption is that I want to hit it with PB Blaster and let sit, then use a left handed #44 to try to get it to come loose, without actually drilling to the depth of the threads. Do I have that right? If so, at what depth do the threads begin? I want to mark the bit so I don't go cutting into the threads.

I have to go into town to get a blower motor for my pellet stove. There is an OReilly's across the highway, so I will go try to find an easy out of the appropriate size to remove the idle tube. Ordered an idle tube from Steiner, so it is on the way today. Hopefully it will be here by Tuesday. I will try to get in touch with Bob McCarty sometime. It would be nice just to chat with him. What do people use to reduce file size of pictures so they can be posted? I have PhotoShop 5, but have only used it a time or two a couple years ago, so I have forgotten the little that I used to know. I am not asking for a Photoshop tutorial. I just want to know if there is an easier way to do it. If PhotoShop is the best way, I will go find a tutorial on Youtube.

I think the folks have you covered. I mentioned 4-48, because it is not the more common 4-40, and just in the event you needed a tap or wanted to check the tap drill size. When I drill something like that out, I want something smaller than the tap drill so it does not disturb the original threads. Usually, the brass stub will just back right out and the threads will be intact, but if you need to chase it out you have the tap size. Also, if you are looking for the size of a fractional drill bit to make sure it is smaller (not everyone has a set of number drills), you can go to a chart online for tap drill sizes and compare to bit something you have that is small enough so it does not touch the base metal. I, too, use pin vises, or even tap handles for hand drilling something as delicate as this to get a good feel for what is happening. Good luck, looks like you are going to be an expert in a number of areas before you are done.