Cub Carb problems (IH carb)

[Xrunner]

I just got this 1953 Farmall Cub yesterday,
the previous owner told me when the you work the cub and get it warmed up sometimes if you shut it down you have to wait about 30 minuted to get it started again (it also carbon fouls plugs), he also mentioned sometimes if you really need to get it started you can disconnect the carb from air cleaner tube (via rubber hose clamps) and it will start.

I drove the cub around some today, it seemed to be running lean (a bit under powered) and would sometimes sputter and die when I would release the clutch.
I tried adjusting the fuel mixture, and I see black smoke whether its set lean or rich, however it doesn't die on take off when I have it set rich, but does sputter a bit and I see black smoke from the stack.

This Cub has a cap over the air intake tube (looks like pre-1970's GM oil cap/vent cap), maybe this cap is to restrictive?
It has only ran on a few brief occasions in the last five years, was also rebuilt and has low hrs (I was told).

I noticed I can turn the mixture screw a couple turns with the engine idling and it seems to sound the same.
I have a bunch of work for the Cub tomorrow and would appreciate if anyone can give me some ideas on what to look for, thanks...John

Edit:: the previous owner also installed a gas shut off valve and emphasized "be sure and turn the gas off when you are done with the tractor".

[Bigdog]

Check the quality of your spark. If it is not a bright blue arc, a tune-up and new coil are in order.

[Eugene]

Complete tune up, replace all fluids, and new coil as Bigdog stated.

Also remove and clean the air cleaner. If you have to remove the air cleaner hose to carburator to get the tractor started, its probably plugged.

"Be sure to turn the fuel shut off." Carburator cleaning and kit.

Sputtering: Clean the sediment bowl and filter.

Eugene

[Rudi]

John:

Edit:: the previous owner also installed a gas shut off valve and emphasized "be sure and turn the gas off when you are done with the tractor".

K, Guess the Welcome Wagon is in order here.. that statement alone indicates a rebuild in my opinion. At least checking the float for sticking against the side of the bowl (check for tap marks on the side), or checking the needle and seat would be adviseable. Check out Lurker Carl's Carb Fixes would be a good starting point. Second, the Owner's Manual Regular Maintenance section would be useful... follow through..

I personally would do a complete oil and fluid change in the Cub. That way YOU KNOW that it is up to snuff. Compare with the Lub Chart in the Owner's Manual.

Also, make sure that you put the steel fuel line back on the system, and don't forget to check the Fuel Sediment bowl and the original shut-off. Make sure ALL the screens are clean.. check the Metering jet as well -- both holes..

Oh, and do what the others said too!

First, to the greatest forum on the internet, and to the Cub Family. You will find that all the folks on this forum are kind, helpful and just full of Cub info and knowledge. They also happen to be the finest folks I have ever met

Ok, so here is the spiel :

I would suggest that you read this thread: New Members and Visitors, Please READ Prior to Posting. There are many great links to informative pages such as the ATIS FAQ's 1 and ATIS FAQ's 2, The Best of H.L. Chauvin who has written very interesting articles on troubleshooting common problems with your Cub.


Also, you might want to visit the Cub Manual Server as there is tons of info on servicing, maintaining and re-building your Cub. In addition to this basic information, there are also a number of other useful tools available on the server. There is the Specialty Services page which has contact info for neat stuff like getting your seats recovered, buying quality Decals, Serial Number tags and a host of other neat items. Also there are the Parts Pages - both Used Parts Suppliers and New Parts Suppliers pages with links to quality dealers. I am always looking for YOUR favourite dealers for New and Used Parts to include here. These pages are intended to complement our Official FarmallCub.com Website Sponsors:

JP Tractor Salvage
Ralph's Cubs
TM Tractor Parts

I would also recommend that you visit Binder Books and purchase the three most important manuals you can own for Maintenance, Repair and Rebuilding your Cub. These are the Owner's Manual, the GSS-1411 Service Manual and the TC-37F Parts Manual. Although they are available on the Cub Manual Server, it is better is you also have your own paper copy. Binder Books is the only Authorized IH Publication Reprint House and they have the best quality manuals available. Most other's are not of the same quality. Just a personal thought here, the I&T Shop Manuals, although helpful in some areas, really are not sufficient for the job. If you wish though, they are good additional reference works.

IF you really want to get the skinny on all things Cub, might I suggest you get a copy of Ken Updike's Farmall Cub and Cub Cadet's . While you are at it Original Farmall Cub and Cub Cadet is Ken's latest addition to the series. Along with Guy Fay's Letter Series Originality Guide, these are three must have's in anyone's collection.

In addition to the above information, don't forget to check out the various articles that are available to help with your Repair, Restore, Rebuild or just your Maintenance Projects. There are a number of sub pages such as Electrolysis or Rust Zapper's, Maintenance Tips, Jigs and Techniques, Implement and Part Sketches and of course the Paint, Decals & Other Finish Questions which has the Paint Chart and the Paint Committee Decisions links.

I truly hope that you enjoy your Cub and that you will be a frequent contributor to the forum. Again, to the Cub Family

[Xrunner]

Geez I thought I got through today relatively unscathed!

Mistake #1, filled the tank with fresh fuel (and felt good about it).
The other mistakes will be popping up soon I suppose

Check the quality of your spark. If it is not a bright blue arc, a tune-up and new coil are in order.

Hadn't even thought about this, I remember having problems in the past with weak spark on other equipment and carbon build up on the plugs was the symptom!

Complete tune up, replace all fluids, and new coil as Bigdog stated.

Also remove and clean the air cleaner. If you have to remove the air cleaner hose to carburator to get the tractor started, its probably plugged.

"Be sure to turn the fuel shut off." Carburator cleaning and kit.

Sputtering: Clean the sediment bowl and filter.

Eugene

I had planned on going through the complete lube chart in the manual before putting the Cub to work, good advice!
Like a dummy I filled the gas tank!
I will disconnect the fuel line and strain that liquid GOLD into a clean container, and do whatever it takes to insure there are no chunks in my tank, and sediment bowl

John:

Edit:: the previous owner also installed a gas shut off valve and emphasized "be sure and turn the gas off when you are done with the tractor".

K, Guess the Welcome Wagon is in order here.. that statement alone indicates a rebuild in my opinion. At least checking the float for sticking against the side of the bowl (check for tap marks on the side), or checking the needle and seat would be adviseable. Check out Lurker Carl's Carb Fixes would be a good starting point. Second, the Owner's Manual Regular Maintenance section would be useful... follow through..
~snip~

Rudi I think every great discussion forum has "link master" a guy or gal who seems to always come along with great links for research, thank you for being so helpful.

I am going to give away my 22 yr old daughters hand in marriage tomorrow, then most likely work till late on the Cub, I will let you guys know how it goes, thanks again...John

[Rudi]

John:

I am going to give away my 22 yr old daughters hand in marriage tomorrow, then most likely work till late on the Cub, I will let you guys know how it goes, thanks again...John

Wow!..

Congratulations to you and of course to your daughter and her hubby to be. I hope that they will be truly happy and that their marriage will last a lifetime and bring lots of joy and pride to all. Grandchildren will be a nice addition as well.

My eldest daughter is 22, but so far she is still in University mode and hasn't met THE GUY yet And neither has my son...

That is ok.. I can wait..

It will probably be one of the most memorable moments of your life to walk you daughter for the last time as the Man in her life, to bring her to a whole new chapter...

[cowboy]

Hi Xrunner

Another thing to check is your timing. I was blaming my carb for running rich and it ended up being I had the timing retarded. I had static timed it and must have bumped it when I tightened the bolt down.

Billy

[Lurker Carl]

The idle jet isn't changing the idle mixture because something is plugging up the idle circuit in the carburetor. It could be the bowl gasket blocking the intake to the idle circuit and/or little chunks of crud caught in the 2 bleed holes just above the throttle plate.

The idle jet in the IH carburetor works opposite of many carburetors, it meters the amount of air rather than the amount of fuel moving through the idle circuit. With that in mind, screwing idle jet in makes the idle mixture richer and screwing it out makes it leaner.

Another bugaboo with the IH carburetor is a warped throttle body casting. If it's warped, you're gonna have carburetor problems until you straighten it out.

[Rudi]

Carl:

The idle jet isn't changing the idle mixture because something is plugging up the idle circuit in the carburetor. It could be the bowl gasket blocking the intake to the idle circuit and/or little chunks of crud caught in the 2 bleed holes just above the throttle plate.

I just learned something new... thanks buddy

[Xrunner]

Wow!..

Congratulations to you and of course to your daughter and her hubby to be. I hope that they will be truly happy and that their marriage will last a lifetime and bring lots of joy and pride to all. Grandchildren will be a nice addition as well.

My eldest daughter is 22, but so far she is still in University mode and hasn't met THE GUY yet And neither has my son...

That is ok.. I can wait..

It will probably be one of the most memorable moments of your life to walk you daughter for the last time as the Man in her life, to bring her to a whole new chapter...

Thanks Rudi,
The look in their eyes today was priceless, they been dating for close to 4 years, the new son in-law is a skilled auto machinist , and one heck of a great guy, I had fun today!

My daughter is still Daddy's girl and knows things won't be quite right till she pursues some form of higher education (some profession she enjoys), she has been working in property management since she was 18, I think with a great husband with fair income and level head, they will both have the opportunity to pursue their dreams.

My eldest daughter is 22, but so far she is still in University mode and hasn't met THE GUY

The classic heart breaker, good job Rudi! When she finds her "GUY" they will both be well on there way to their life goals and maybe won't have to go through the changes and adapting (frustrations) the younger couples do.

Hi Xrunner

Another thing to check is your timing. I was blaming my carb for running rich and it ended up being I had the timing retarded. I had static timed it and must have bumped it when I tightened the bolt down.

Billy

Billy,
The Cub did backfire a little out of the stack a couple times come to think of it (maybe excess fuel in the stack, or timing), what setting do you think I should use running this modern crappy gas, 2 degrees advanced?, 4 degrees advanced?

The idle jet isn't changing the idle mixture because something is plugging up the idle circuit in the carburetor. It could be the bowl gasket blocking the intake to the idle circuit and/or little chunks of crud caught in the 2 bleed holes just above the throttle plate.

The idle jet in the IH carburetor works opposite of many carburetors, it meters the amount of air rather than the amount of fuel moving through the idle circuit. With that in mind, screwing idle jet in makes the idle mixture richer and screwing it out makes it leaner.

Another bugaboo with the IH carburetor is a warped throttle body casting. If it's warped, you're gonna have carburetor problems until you straighten it out.

Carl,
I was hoping to get this girl to work fast (weeds are growing) but you and the others are right, and I appreciate your guiding me in the right directions, although I am old enough to know better, its good to have knowledgeable people steering me away from the "Mickey Mouse" approach!
I will clean and inspect the carb, the fuel system, air filter system, and see what happens.
I am curious about the zenith carbs I have read about, wondering if I wouldn't be best of to install a zenith carb in the future, reliability is the top priority!

Didn't make it to the farm today, I will be there 5:00 am tomorrow though and will spend the day nurturing the new Cub
take care...John

[Lurker Carl]

Congratulations, John, you're not losing a daughter but gaining a son.

The IH carburetor is very reliable once you fix decades of previous "repairs" and accumulated crud that plagues the fuel systems of old machines. Often, a Zenith carburetor is purchased to replace the original "junk" carb while problems still reside in the tank (rust, dirt and water). Invest in the IH carburetor kit and several hours of TLC to undo the abuse by gorilla mechanics. Follow a systematic approach to the repairs and everything will work out to a happy ending.

Don't advance the spark, exhaust valves and seats don't take kindly to the extra heat.

[Xrunner]

Congratulations, John, you're not losing a daughter but gaining a son.

The IH carburetor is very reliable once you fix decades of previous "repairs" and accumulated crud that plagues the fuel systems of old machines. Often, a Zenith carburetor is purchased to replace the original "junk" carb while problems still reside in the tank (rust, dirt and water). Invest in the IH carburetor kit and several hours of TLC to undo the abuse by gorilla mechanics. Follow a systematic approach to the repairs and everything will work out to a happy ending.

Don't advance the spark, exhaust valves and seats don't take kindly to the extra heat.

Carl,
Actually it will be another generation, its really amazing I am actually still having thoughts of the Cub throughout this major earmark in our lives
The reception consisted of 2 very compatible families meeting and learning more about one another, was a great (unproductive) day

In the 1960's GM used the Stromburg carbs on low cubic inch motors which were naturally upgraded to Carter,Holley and
later even a few motor craft carbs, I wanted to be clear on the reliability of the Cub/w IH carb, and thank you for setting me straight!

I intend to be thorough, but cheap at first, I need this tractor running yesterday (my own fault).
I will make sure everything is lubed properly, go through the fuel system, do what I can with the carb, and off to work she goes!!!
In the meanwhile, I am ordering the IH carb kit, and will see if there are any other problems (ie over heating, etc...)

I will let ya know how it goes, thank you for your help...John

[Rudi]

John:

In the meanwhile, I am ordering the IH carb kit, and will see if there are any other problems (ie over heating, etc...)

Well, remember that the Cub has a Thermo-Siphon and overheating isn't really an issue unless you let the coolant somehow drip out. Cubs find their own level for the coolant.. and it takes a while to get used to it. It should be about 1-1/2" or so BELOW the neck of the rad. Also, make sure to PRE-MIX your coolant. Without a recirculating pump, there is no way for the coolant to mix if you just add anti-freeze... or just water to the anti-freeze.

I wanted to be clear on the reliability of the Cub/w IH carb, and thank you for setting me straight!

the reliability of the IH 3/4 Updraft Carb when PROPERLY re-built/repaired/maintained and serviced on a regular basis with the PROPER parts is un-matched. I have a Marvel Schleber Carb that I am not all that happy with which is a retro-fit to Granny. My what a POS that is... in comparison the the UpDraft

I have no experience with the Zenith, and I hear that they are good carbs and a must on the Numbered Series.. but to my mind and the majority of Cub owners, a well serviced Updraft is the most reliable there is.. The more I play with these carbs the more convinced I am of this. Ellie always starts first tug on the starter... and the carb has a lot to do with it.

But remember, each Cub is like a child.. they are different and they have their own personalities and idiosyncracies. You just gotta learn your Cub/Cubs.

Oh, I forgot. You especially since you have a truck garden. I betcha you can't stop at one

[Lurker Carl]

That MS carburetor on Granny is a POS because it isn't designed for a Cub engine. Although you can swap various mfg carbs around to different engines and they seem to perform okay, carburetors are designed to fit specific applications. So, performance suffers because the carburetor isn't able to provide the optimal fuel/air ratio.

IH contracted with Zenith to replace the IH carb when they "souped up" the C-60 because that little venturi couldn't handle higher rpms effeciently.

[Rudi]

Carl:

You sure got that right

On a Pony, it would be a great carb, cause that is the application that particular carb was designed for. Putting a Pony carb on a Cub is like putting a Renault carb on a VW... ain't gonna work.. but it will be a nice carb to trade somebody for another IH 3/4" UpDraft

But, from what I have read over the forum, you have to be careful which Zenith you buy, all are not created equal as Zenith builds carbs for all kinds of applications.. As you said, even though it may fit the manifold, doesn't mean it is gonna fill the bill