Winter is quickly approaching, and while we don't see the frost accumulating quite as much over here on the West Coast, the fact of the matter is the temperature is dropping and the colder it gets, the harder it's going to be to crank over and get your carbureted engine started. We're sure your mill will love the chilly-thick air after it's running, but until that moment you could be in for some work, requiring a bit of patience. Besides, cranking over a frozen motor repeatedly is a good way to kill your starter, not to mention drain your battery. Who wants to be stuck in the cold like that? Add a supercharger or high-compression to the mix, and the only thing that's going to be running is your heart rate from all that erratic key turning and gas pedal pumping.
What prevents the engine from firing in cold weather? Basically it's a matter of atomizing the fuel properly and efficiently. In a nutshell, droplets of fuel have a difficult time evaporating in a chilly environment. So during cold weather, with the help of a choke-valve, the level of vacuum inside the carburetor rises, which also causes a proportionally greater amount of fuel to be sucked out of the main jet and into the combustion chamber, essentially cutting off air, enriching the fuel-to-air mixture, and allowing the engine to start more easily. Once the engine is warm from combustion, the choke valve opens back up, restoring the carburetor to normal operation.
While some factory cars have a manual option for the choke, we couldn't pass up a chance to upgrade our carburetor with an electric-choke kit from Holley, priced around $60 for the complete kit (PN 45-244S). The match was seamless and took approximately two hours from start to finish. Bring on the cold starts! We're not scared.
What We Did
Converted our Holley 700-cfm carburetor from manual to electric choke
No more cold-crank starts
To get a better handle on...
To get a better handle on the install, we went ahead and removed the carburetor from the top of the engine. We also propped the carburetor up off the work area and then we removed the manual choke housing and all of its associated linkage, keeping the bolts off to the side for later.
First, we removed the screw...
First, we removed the screw that holds the fast idle levers. We set the screw, spring, and small lever to the side for a later time. The larger lever we won't need because the kit comes with a new one. Using the original spring and small lever, we reassembled the parts to the throttle-shaft with the new larger lever from the kit and bolted it into the body of the carb with the original screw. This took a little effort, but we got through it by taking our time.
We had to assemble the choke...
We had to assemble the choke housing to the main body of the carburetor and then took special note of where the fast idle cam (red lever) needed to be after being bolted onto the main body. We then moved the fast idle cam above the choke rod.