Engine runs only on full choke

[Gbuckbee]

HI Guys,

This spring my CCKW will only run on full choke, the minute I back it off of full choke, even the slightest bit she dies.
I have the Zenith Cast iron carburetor - very simple, but can't seen to get it right@!?*
Rebuilt it @ 2 years ago..... all was good engine ran fine, now suddenly this spring, after a long mild winter, I have this new problem.
So I have tried all of the usual simple stuff, like trying to find a manifold leak or vacuum leak, or air leaks at base of carburetor,....everything seems to be tight. (Used either to spray around - hoping for an increase in rpm)...nothing
Took carburetor all apart again - everything seems ok,.....fuel system is pumping good.

I am sure I am not the only one who has had this problem, so what are the usual causes for this on the CCKW.

Any and all advise welcomed....frustrated

gib

[Joe Gopan]

Check for fuel delivery, remove the "sight Plug" on the bowl, is the fuel level OK?- My two cents.

[motto]

Take a look at the governor, if installed, and make sure that it hasn't failed. I've had this happen and had to remove the butterfly to get home.

David

[kw573]

Certainly sounds like a major vacuum leak. Have you isolated the brake booster vacuum take-off in case something has jammed/failed in the booster system?

Another 2 cents worth.

Sam.

[Gbuckbee]

OK, so we got into this again this last weekend, and it just came down to the carburetor again, so we took it apart, one more time,....and 'walla'....we found a slight blockage in the main jet,...must have missed it the first time........runs fine now.

thanks for all of the help.

Now back to work on the M-34,

gib