Glossary entry (derived from question below)
English term or phrase:
choke/throttle
English answer:
choke = valve that reduces air flow to warm a cold engine / throttle = accelerator
Added to glossary by
Charles Davis
Dec 3, 2017 08:28
6 yrs ago
9 viewers *
English term
choke/throttle
English
Tech/Engineering
Transport / Transportation / Shipping
outboards
What is the difference between a choke and a throttle?
Context:
Choke: "Choke - Pull out when starting a cold engine."; "Crank the engine over while pushing the key in to engage the choke solenoid."
Throttle: "Throttle grip - Controls the engine speed and shifting."; "Throttle only button - The throttle only button allows throttle advancement without shifting the engine."
This is an instruction for an outboard.
Context:
Choke: "Choke - Pull out when starting a cold engine."; "Crank the engine over while pushing the key in to engage the choke solenoid."
Throttle: "Throttle grip - Controls the engine speed and shifting."; "Throttle only button - The throttle only button allows throttle advancement without shifting the engine."
This is an instruction for an outboard.
Change log
Dec 17, 2017 05:19: Charles Davis Created KOG entry
Responses
+10
25 mins
Selected
choke = valve that reduces air flow to warm a cold engine / throttle = accelerator
I can remember the days when cars had a manual choke. It was a knob on the dashboard and on cold mornings, when it was difficult to start the engine, you pulled it out. It operated a choke valve, which is a valve that has the effect of warming up a cold engine more quickly by increasing the proportion of fuel in the air/fuel mixture reaching the cylinders. It does this simply by restricting the air flow and therefore reducing the proportion of air in the mixture. So the mixture burns hotter and the engine runs faster.
https://en.wikipedia.org/wiki/Choke_valve
The throttle is another name for the accelerator. It regulates combustion by regulating the amount of either air or fuel in the mixture, depending on the type of engine. In a petrol engine it's usually the amount of air. As with the choke valve, when the amount of air is reduced, combustion is increased and more power is produced. The main difference, apart from the fact that the throttle sometimes uses other ways of achieving the same result, is that the choke is engaged and left at a particular level, raising the richness of the mix by a fixed amount, and is used to warm the engine when it is cold, whereas the throttle allows the driver to constantly vary the fuel/air mixture and therefore the power, and is used to control speed.
https://en.wikipedia.org/wiki/Choke_valve
The throttle is another name for the accelerator. It regulates combustion by regulating the amount of either air or fuel in the mixture, depending on the type of engine. In a petrol engine it's usually the amount of air. As with the choke valve, when the amount of air is reduced, combustion is increased and more power is produced. The main difference, apart from the fact that the throttle sometimes uses other ways of achieving the same result, is that the choke is engaged and left at a particular level, raising the richness of the mix by a fixed amount, and is used to warm the engine when it is cold, whereas the throttle allows the driver to constantly vary the fuel/air mixture and therefore the power, and is used to control speed.
Peer comment(s):
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Tony M
3 mins
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Thanks, Tony! I suddenly had a nostalgic vision of the choke on my family's first car, a Morris Traveller, when I was a child. I can even remember the registration number: 345 HPC.
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Jack Doughty
: My first car was a 1953 Volkswagen Beetle, reg. HRD 972, and it had a manual choke.
38 mins
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Thanks, Jack. Memory lane!
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Mark Nathan
: I remember a sensitive old mini that required all sorts of rituals on a cold morning: not leaving the choke out too long, pumping the accelerator, counting to ten, and of course talking to the engine!
2 hrs
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Thanks, Mark! Yes, cars used to need coaxing. They were more human. And I remember the thing about leaving the choke out and flooding the engine; you'd never get it started!
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acetran
6 hrs
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Thanks, acetran!
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philgoddard
: That's amazing. My grandfather had a Sunbeam Alpine, registration 33 HPC. He lived in Caterham.
7 hrs
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Small world. Perhaps it was done by area. We were in Surrey too, in Wallington, a bit further north. Thanks!
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Helena Chavarria
: The first car I remember was a pink Vauxhall that my mother used to call 'Rosabella'. It had three gears and the lever was in the steering column. The registration number was 431 TKR
11 hrs
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Thanks, Helena :) This is fun; it's like one of those car forums. It goes to show how you remember these details from childhood, when everything was so vivid. I can't remember the registration number of own first car!
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Daryo
: basic stuff for any petrolhead worth that name - should know that, even if kicked out of bed terminally drunk if the middle of the night ... // yes, a manual choke, when was that? eons ago ...
15 hrs
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Quite a while, yes. Thanks
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B D Finch
: Strange how nobody claims to remember as far back as when cars had starting handles, or the ones with retractable shafts so you could harness up the horse if they wouldn't start.
1 day 6 hrs
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I don't think we have any centenarian contributors, alas. Thanks!
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Terry Richards
: B.D. I (just) remember starting handles and have in fact used one. They were pretty much gone by the time my motoring career started but some of my first vehicles were pretty old and didn't always have good batteries!
1 day 8 hrs
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Thanks, Terry :)
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Neeraj Jain
7 days
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Thanks, Nicky :-)
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4 KudoZ points awarded for this answer.
Comment: "Selected automatically based on peer agreement."
Discussion
The throttle/accelerator however, does not change the fuel/air ratio - it just controls how much of the mixture is admitted into the cylinder(s). This in turn, changes the power output.
The above is true for petrol/gasoline engines, it's different for diesel engines but I doubt that this is a diesel outboard!