farmall C

[sandel]

Have a C that starts and runs fine but only with choke full on. Have not been able to locate an air blockage. What are we not doing that we need to do?

 

[Dave BN]

You need to find where extra air is getting in. Look for loose screws that hold the bowl to the body of the carburetor or a bad gasket where the carburetor is bolted to the manifold. Also check if the manifold has any holes burned thru.
You don't have an air blockage you are getting extra air so having the choke on is limiting the air your getting to the carburetor. Could also be a miss adjustment of the carburetor.
Dave

 

[rustred]

carb needs a going over plus check your fuel supply to it.

 

[sandel]

Oh yeah-head on backwards about blockage. Had carb off to clean and inspect. Had not wanted to start before but started right up after carb work. Fact that it runs smooth with choke out made us discount the adjustment factor.

Your reference to the manifold as an air leak location seems right. Is it a matter of visual examination or is there some kind of test that would affirm or rule out possibility? Thanks.

 

[jimtrs]

Using the choke helps riches up the fuel mixture.
See rusted's reply. Sounds like a dirty carb (blocked, partially blocked passageways).

 

[560Dennis]

My Farmallsc with zenith carburetors have had issues with idle circuit blockage . In the bowl theres at bottom of idle circuit bore .04 vertical hole from main jet bore to the venturi at butterfly valve . I use a #80 drill .04 inches to clear it by hand use ing finger and thumb to rotate drill. The blockage is hard encrusted residue from old fuel and rust. , Ive not had any luck with carburetor cleaners to remove it.
If your carburetor isnt a zenith then this procedure is not for your carburetor .
You still have a problem ,suggest a vacuum gage to diagnose it.

 

[Brownie450]

To check for manifold or other air leaks, take a squirt
can pump oiler & squirt # 30 engine oil around all gasket
areas. If you have a leak, the engine will smoothe out &
run normally with the application of the oil.
Makes a mess, but cheaper than guessing.

As far as starving for fuel---our Super C with a Zenith
carb is very sensitive to float level. Doesn't take much
to go from over rich to starving.
Jim