Ford Forums banner

1 - 5 of 5 Posts

·
Registered
Joined
·
344 Posts
Discussion Starter #1
Just a little question I have to ask which may sound a little trivial. On carbie seat needle valves you usually got the little spring loaded pin on the bottom of it which contacts the tab on the float. What is this little spring thingie for does anyone know? The needle valve is closed when the top of the valve contacts the seat and closes yeah? but then theres another, mil or two of movement that the float has. Anyone know? Does the float actually move up after this point? or does it depend on a number or things, such as float buoyancy? yada yada?
 

·
Registered
Joined
·
330 Posts
73falcongt said:
Just a little question I have to ask which may sound a little trivial. On carbie seat needle valves you usually got the little spring loaded pin on the bottom of it which contacts the tab on the float. What is this little spring thingie for does anyone know? The needle valve is closed when the top of the valve contacts the seat and closes yeah? but then theres another, mil or two of movement that the float has. Anyone know? Does the float actually move up after this point? or does it depend on a number or things, such as float buoyancy? yada yada?
Don't have time to answer properly but the spring keeps light pressure on the needle all the time. Probably stops float bouncing as well.
 

·
Super Moderator
Joined
·
3,754 Posts
Good question. I am guessing, but it probably helps stop the tang on the float bending or the needle valve sticking over time in circumstances where the G forces from hard cornering or steep inclines means the float chamber level at one end or side is overfull and the float is exerting additional closing pressure on a closed needle valve. I guess it also dampens the closing system it what can be a jiggly ride for the float
 

·
Super Moderator
Joined
·
3,754 Posts
Ok the text ( Automotive Technolgy - A Systems Approach Jack Erjavec & Robert Schaff Delmar New York 1992 Page 561) says it's to stop the float (and therefore I assume the valve) bouncing and vibrating so my dampening guess and Northey "bouncing around" was right.
 

·
Super Moderator
Joined
·
3,754 Posts
Also see http://oldmanhonda.com/MC/Rcarbs.html
FLOAT VALVE and SEAT:
The small torpedo shaped piece of metal hanging from the float is the float valve. Clean it up and check if the nipple-like pin in the top (closest to the float) moves in and out freely. If it doesnt, soak it in carb cleaner until it moves freely. This spring driven nipple serves as a shock absorber to hold the valve in place.
 
1 - 5 of 5 Posts
Top