This a question for informational purposes only. I neither have nor expect to ever have a need to have this information. It's just something I laid awake wondering about one night recently. That's my polite way of saying please don't ask me what the engine or carburetor or car or etc. is, 'cause there ain't any. The question: Is it possible to switch an electric choke to manual or a manual to electric? If possible what would be required to do so? I'm thinking that the end of the butterfly shaft would be different. Thanx for helping to educate me. It is conceivable, although highly unlikely, that I might find a carb at a swap meet someday that has one or the other and I'd like to buy it and switch it to the opposite.
It all depends on what carb it is, of course. If the carb has a round housing that will accept a different cover, that has an electric heater, or has a heat tube hole, then it's pretty easy. But there are lots of designs that don't have that feature, and it's not so easy. Aftermarket carbs are usually designed to work with either manual or electric, and there are usually kits to go from manual to electric, but not the other way.
You used to be able to buy a spool to put in place of the electric choke and use a cable to operate it. Holley sells an adaptor that replaces the electric choke. I can remember people rigging up all kinds of things to go manual from electric. Buy the carb. Odds are you can figure out a way to attach a manual choke or replace the electric choke. Both will work. IMO.
^^ Wvenfield Pretty well nailed it. They did and probably still do sell manual choke conversion kits that replace the bi-metal spring on the carbs with the spring on the side of the airhorn. Similar to this. You would have to find the right one for your carb. Amazon.com: Dorman 55101 Choke Conversion Kit: Automotive
Thanx guys. Like I said I probably will never need this information, but now I know something I didn't before.
Most manual choke factory carbs had a spring loaded butter fly that would open when the engine started. To keep the engine from flooding. Aftermarket kits dont have that feature.
I never liked electric chokes.. I'd rather run no choke at all, you can do that by the way.. I like the cable choke best.. You can use it diagnosing troubles.. Like closing it a little while driving to see if your running rich or lean..
Yes The carburetor I bought for my wagon had an electric choke, the 292 had been an automatic choke with the heater tube, the original engine had a manual choke cable. I bought the kit from holley and changed the carb to a cable choke and blocked off the heater tube in the intake. Works good and I can control the choke as needed which is good with our weather. Sent from my iPhone using Tapatalk
A follow-up question is often, "So how do I wire up an electric choke?" I just answered this over on a Ford truck forum. Other makes are similar. Here is my answer. There are two ways to wire in the electric choke that I use. It is necessary to wire the electric choke such that voltage is going to the choke to open it ONLY when the engine is running, not with the key 'on'. If you wire the choke in to a circuit with the key 'on' then there is the possibility that voltage to the choke will open it even though the engine is not running, not producing heat. So in the case of an engine that stalls after initial start, or the driver turns on the key to listen to the radio, or powder her nose, etc. the choke may open even though the engine is not sufficiently warm to continue running. The first method is how Ford did it for years. The factory choke gets hooked to the "S" terminal of the alternator. The output of this terminal is AC. If you try to get a voltage reading using the DC scale of your VOM it'll read something like six or seven volts. This is fine for the original factory carb. it was designed to run with this voltage, however, if its an aftermarket carb, the choke on these is designed to run w/ 12v DC. The second method is one I have used on hot rods using a single wire alternator. Use a two-pole oil pressure switch with a normally open (NO) terminal and a normally closed (NC) terminal. The NC terminal operates an oil pressure 'idiot light' No oil pressure = idiot light 'on'. Oil pressure around 7 psi will open that side, switching off the idiot light. You want to wire in the choke cap to the NO terminal. Engine not running = open circuit to the choke. Engine running (i.e. oil pressure >7 psi) = power to the choke. I don't know the amp rating so let this switch power up a relay which actually switches main power to the choke. This eliminates high amps flowing thru the pressure switch. Here's an example of a typical two terminal switch (this one actually has three - one for power +12V): https://www.summitracing.com/parts/...0hnrhjfp-wCsAk1RyD1kSGu_EfPVNYRAaAgdaEALw_wcB I also recommend you fuse the choke circuit, just to be safe.
I used to remove the butterfly and leave the fast idle cam with either manual or electric choke. One carburetor I rebuilt had screws securing the butterfly that refused to cooperate, so I drilled a couple of holes in the butterfly to create an air bypass to prevent flooding.
I've been running the Summit type switch for about 15 years on my sedan. But I got it from Napa or Advance or somewhere. Works great. Never had any problem with amp rating. Seems the switch is good enough to handle it. .bjb
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