1979 Cub needs a carb rebuild!

[boldpsi]

All,
yep, i know it's been quite a while since i was a contributor

my apologies... just trying to retire, but it has taken me 35 years so far

so...
if i were to be in need of a "complete carburetor rebuild kit" for a Zenith carb with 71523C-91 and 13794 stamped on it, which one should i get? there's like 100 of them on the Internet in various states of "completeness".
I think i need a carb rebuild because:
a) Cub runs great until it stalls. then it starts right up again if i choke it.
b) Constantly stalling Cub is not fun.
c) main reason: already removed carb and cleaned it, then ran out of paycheck, but i get paid again tomorrow!

What do y'all suggest (i mean about the carb, not the paycheck)? i need the one with the wide gasket: (i'll post a pic as soon as i remind myself how to do dat).


dave

[boldpsi]

of course, i just found the thread:
IH Carb Rebuild Procedure
that i'd seen referenced before, but didn't find until now
i guess this answers all my questions, but please feel free to add additional comments/tricks/tips, i'm only semi-handy!
thanks, all,
dave

[LRiddle]

Could also be a fuel flow issue. I would rule that out first before spending time and money on a carb rebuild.

[Bob McCarty]

If you're not sure about the kit, I'd suggest McDonaldcarb.com. You can call or email them with your carb #'s and they can sell you the right one. Isn't the how to for the IH carb and not the Zenith?

Bob

[staninlowerAL]

I believe Don McCombs posted manufacturer's rebuild instructions for a Zenith carb not very long ago. I have the file but it's too large to post. Send me a PM with email address and I can get it to you.

[boldpsi]

all,
thanks for your responses!
Don: i did order parts from your article "IH Carb Rebuild Procedure (#p669498)". it sounds like i should un-order them?
i did send staninlowerAL for a copy of the Zenith document.
RATS! i didn't even notice that it says clearly "IH Carb...", i just assumed that meant "IH tractor..." as opposed to "IH Carb (specifically)"...
dave

[Glen]

Hi,
Have you cleaned the fuel strainer under the gas tank, they have a screen in the top, above the gasket that can get plugged. Sometimes the screen tears from being old, and needs replacing.
There might be something in the strainer inlet, in the gas tank, making the fuel flow slow.
It is helpful to put the Touch Control arms in the rear or down position before working on the strainer, it's easier to get at it.
Here is the gasket and screen for the strainer at TM Tractor, if you want to see them.
You could clean the main jet and see if that helps, they sometimes get plugged with dirt. It is the hex head part in the 2nd pic, at the bottom of the carb.

http://www.tmtractor.com/new/fl/426fp.htm

http://www.tmtractor.com/new/fl/235fp.htm

[boldpsi]

Glen, and all,
Thanks so much for your thoughtful suggestions, I think you may have been right on...

So I got the kit and dug into the job... Only to find out by the third step or so that I don't have special wrench C161-82 or ...-83 that remove the fuel valve seat nor any of the 5 other special tools

So after quitting for a while I kept going, figuring I could at least clean some of the parts removed so far, and started with the brass fitting the fuel line connects to. When I removed it, I realized soon that the screen on it, that inserts into the carburetor, was almost 40%, maybe more full of what looked like cotton, with some big "twigs"! So finally I figured out to spray it out with brake cleaner and it's clean now
Had I done this first I wouldn't have gotten into the whole job, I think, but maybe it's a good thing. I'll try to read all the documents first now and see if I can do it.

So far, I'm having trouble finding the special tools on the internet... is this so newbies like me don't do more damage ?!

Little steps,
dave

[boldpsi]

So...
no one knows about special Zenith carburetor wrench C161-82, nor ...-83, nor any of the 5 other special carburetor tools ??!!
i ordered what i hope to be the correct kit from McDonald carb yesterday...
take care,
dave

[tmays]

Been awhile since I've taken one apart, but I've never needed any special tools.

[Boss Hog]

Big flat screwdriver , grind it to fit the seat.
Boss

[boldpsi]

All, especially "LRiddle",

so, i had the carburetor rebuilt, got it installed, and happily it started right up... then exhibited the same exact problem it had before: after putting it in gear and running for a very short period of time, it stalls. then, i pull the choke, it starts right up, put it in gear, let out the clutch, go 10 feet, and it stalls. Repeat. RATS!!!!

so, i re-read the posts, did some more searching, and decided to check the fuel supply from the tank down. i unscrewed the gas cap, shone a light in the tank, and this is what i see inside the fuel supply "port":


upon further investigation, i found the whole sediment bowl fixture to be fully clogged with all kinds of gross, recent and long-since-dead grub bodies!!! i couldn't even blow through it! so, i cleaned all that out, blew through it, and then put it all back together, and it ran much, much better. i did realize, though, that there must've been more grub bodies in the tank because after it ran well for a while it started sputtering. so, i checked the tank with a flashlight again, and i can see some more bodies in there again

Also, there is no screen between the sediment bowl and the fixture, so i'll have to do the whole process again after i get a screen from McDonaldCarb.com, but at least i think i've got it licked

Thanks LRiddle for figuring it out, even though i didn't take your advice at first

take care, all!
dave