I don't really know what i'm talking aboutso bear with me. I was told that there is a tube going from the manifold to the choke that brings hot air to it to turn it off, i know that I don't have it hooked up, then there is another one that comes from the carb and goes down there, it looks like a vacum hose. please help it runs like crap and sucks ALOT of gas during the winter, it loads up and hesitates when its cold out HELP

 

Bear -- yes, some Carter YF carbs have what you describe. I think its called an "environmental" choke, meaning that it gets the heat from outside. The other type of automatic choke has electric input from one of the alternator fields, which over a few minutes opens the choke.

In any case, without knowing more about your carb precisely, and maybe even then we are going to be hard pressed to help. I'd suggest a Chiltons for some diagrams so you can make sure you know what you have got.

As for not running well and drinking gas. Sounds like it could be carb related, but could be timing or other ignition. Or Or Or....... Better start getting some exact details for the group and perhaps answers will emerge. Of course, for starters, pull off the air cleaner in cold weather, after about 15 minutes running, and see where the choke plate is. It should be vertical. If not, well then you are at least partially correct -- your choke is not opening.

Oh -- parts places offer nice manual choke conversions for the old carter YFs. Rather common -- tells you that you are not alone. For my purposes, a manual choke is the only way to go. You know where it is and you know when its open.

Addendum -- looked at your sig -- 85 300 had Carter YFA I think. Complicated beast with lots of pollution ports. But I recall that there were some late85-86 engines that had old carter YF, just before the went to EFI. You need to ID your carb for sure.

 

what I really want to know is where the heat tube for the choke goes into the manifold

 

Somewhere around 4-5 exhaust port, in the exhaust manifold. But you may not even have a carb set up for this, and/or your manifold may not have the port.

 

85 YFA is gonna have an electric choke. Look on the choke housing itself for an electrical connection. The carb body itself is used as a ground. If you have above, then with the ignition ON check for 12V (or batery voltage) at the connector. If so you either have a broken coil linkage (inside) or a bad coil linkage heater.

Pull off the choke housing. look inside, you'll see a "clockspring" with a hook on the end. If it's broke you need a new housing. If not check the heater for continuity. Set your VOM to oHms and put one lead on the center tap on the outside and the other on the edge metal. If you have infinate or no reading, then the heater is BUSTED!

Take the housing to your local parts house and order a new one. Take the numbers off the carburetor tag also.

Larry

 

the style i'm used to uses hot air from the exhaust pipe. i recommend wiring the electric choke. as far as the rough running vac. sounds like the prob. replace the gasket under the carb and plug all other vac leaks or lines not in use.

 

THANKS for the help !!