The history and theory of carburetors

[karl61]

I'm studying carburetors. I bought the least expensive one on ebay for about 4.95.  This one came off of a cb750 and it's a keihin.

so far I've read where the Diaphragm is up top, the floats on the bottom. Not sure what the line does on the bottom of the float or the other line right before it enters the cylinder.

[Arnie]

Karl,

If by "line" you mean the brass spigots to attach hose to, the one from the bottom of the float bowl is a drain and the one on the engine side of the throttle plate (closest to us in the pic) is a manifold vacuum connection.  This could be used for varying the ignition timing or more likely to open the fuel petcock when the engine is running.

Cheers,
Arnie

[Travis398]

CB750 

[Kopfjaeger]

there is a book by Carl Shipman. Its on tuning dirt bikes, but has breakdowns and schematics and a lot on all carburettors. might be useful to you, as soon as i get it back i will let you know the title!!! carbs include kehien, mikuni and a lot i cant remeber!!!

[SlowOldGuy]

Have you visited the files section?  Lots of good carb information in there.

DavidR.