hey guys i'm just wondering how a carb works. i got a idea on how they do but i i'm not to sure. and links or anything else would be nice. i just would like to know for further carb selection

 

The basics? When you press the pedal the linkage gets pulled, actuating a lever that pushes on an accelerator pump. This squirts gas, gas goes through jets into the engine. Thats a real basic rundown. Of course that isnt anything about vacuum secondaries (which open according to engine need) or mechanical secondaries (just what it sounds like) etc.

 

thats the accelerator pump. not how a carb works. believe it or not, alot of carbs dont have accel pumps... esp on small engines.





heres a good artical on it: http://auto.howstuffworks.com/question377.htm







in a nutshell:

ever blow air across the top of a straw? the moving air makes a low pressure above the straw, the liquid goes up, and its blown out.
carb works the same way. the venturis are smaller spaces. if you're moving X amount of air, and you make the hole smaller, and you still need to move X amount, it has to go faster.

so this faster air blows by the holes(top of the straw) and these holes are leading into the fuel bowls. so it "sucks" the fuel out.
how much it sucks out depends on the size of the "straw" aka the jet.

thats over simplified, but you get the idea.

 

Pretty much any carb he is gonna put on his car will have an accelerator pump. Like I said the basics. Fuel is pushed, comes out the jet. Want to go more in depth fine, but I just gave the basic operation.

 

Did someone take your red stapler again? Hide the matches....

 

I'm, Im gonna burn the place down........

 

ummmm, yeeeeeeaaa, im going to have to ask you to move your desk down to the basement.... thankx.




lol


anyhoo what ljnowell was talking about:
when you suddenly open the throttle, the air isnt moving that fast yet.. but you need more fuel. the accel pump shoots more fuel in when the throttle moves fast.

the accelerator pump works like a squirt gun. remember the cheap old squirt guns?
if you slowly squeezed the trigger, only a little comes out, and it drizzles.
if you quickly pulled it, it shot out fast and far.
thats how the accel pump works.


you slam the gas down fast, it shoots alot of fuel in.
you slowly roll on the throttle, only a little drizzles in.

it makes it so the engine doesnt "bog" when you mash the gas.