20mm Carb info?

[azbill]

I need some help finding out what carb I have
I bought 2 carbs off of e-bay for 26$ (shipped)!!!
they are supposed to be 16mm, but I measured the opening and get 20mm
I e-mailed the guy I got them from, but still haven't got a reply
this link is the same set,
http://cgi.ebay.com/ebaymotors/2-CA...006QQitemZ160226751375QQrdZ1QQsspagenameZWDVW
when they came there were 2 hoses connected...
one was at the top beside the slide (which I assume is fuel inlet), the other is coming off the bottom of bowl, the use of, I'm not sure
there is also a petcock on the side of the bowl, which I think is for draining
I also am going to make up a thumb-shifter type deal for the cable actuated choke
if anyone can help with any of my questions, or tell me where to find info I would be very greatful

the markings on the side say 'Sheng Wey' with a large K in the casting
the rest of the markings are printed:
TBT125 1J07
0310 0721
there is also a large 'K' at the front of the above numbers, and the same size '11', at the end
pics below

 

[azbill]

thread title error

could a mod please edit the title to show 20mm please
...brain fart on my end

 

[Abeagle]

From the pictures I can tell you the hose on top is for the throttle cable and the one on the float bowl is the fuel inlet with a built in shutoff valve.
The small outlet on the float bowl is probably a float bowel over flow outlet, you should have a hose on that drops down below the bottom bracket to dump fuel over flows in the float bowl

 

[wildemere]

Carb size is usually measured where the venturi is smallest.

http://en.wikipedia.org/wiki/Carburetor

Read that

 

[misteright1_99]

You could measure the inside of the manifold side (in inches) then use the attached conversion site to covert to millimeters.
http://www.sciencemadesimple.com/conversions.html

 

[wildemere]

Its measured at the narrowest part of the venturi, not an easy place to measure without an engineers inside micrometer.

Do you understand the venturi effect? Its how carburettors function.

 

[fastboy9]

Nice looking carbs, ye that other pipe is definetely a fuel overflow to stop it flooding, I've seen them before on pocket bikes

 

[Large Filipino]

Where is this going to? A Happy Time?

I would imagine even a carb bigger than 20 would still work,cause like in cars,you can get a bigger carb than what the engine needs,which is usually what gearheads do.

 

[azbill]

LF, yes, it's going on a 70cc livefast engine
already made a plate to be welded on a steel manifold so we can bolt it up
hope to get it welded, mounted and tested tomorrow
I will let everyone know if it works or not
seemed like a cheap enough experiment

 

[fastboy9]

Any luck with the carbs? Look forward to hearing the results, they look really smart too