How do you tell what mm the carbuator is?

[sheba]

I have a Redstreak 50 Qt _3 . The carbuator is marked CVK standard of Zc 080420a . How do you tell what MM the carbuator is. The  carb intake side od 28mm id 14mm , air intake od 39mm id 30MM . Is the cvk the brand of carb?  I had girl clock me in her car  at 47 miles a hour and my speedomiter said 45 with 185 lb rider. It took me about 1/2 mile on flat ground with no wind. to reach 45.The best i can tell this bike is stock. The orginal owner drove the 2008 bike 321 miles with no shop work done and he  had limited mechinail abilty. I see that alot of 50cc  dont go but 35mph  and with mods 45.The only restricion i see is small pipe in breather.When the carb was flooding and with breather off i had bike up to 51 mph.I did hone out the jet 2 thousands but can find no other modifcations.I wanted to no if carb is a cheap o or a good one?

[Fox]

Get one of these calipers from Harbor Freight Tools and measure the small side of the carb like shown in the pic below. The pic shows a 19mm stock 50cc 4 stroke carb.

 http://www.harborfreight.com/catalogsearch/result/?category=&q=caliper

[sheba]

Thanks Fox. Is this photo of the breather side or intake manifold intake side of carb?

[Fox]

Thanks Fox. Is this photo of the breather side or intake manifold intake side of carb?

Intake Side   You always measure a carb's inside diameter at it's smallest point.   

[sheba]

Thanks. With out a manufactor name on carb how do you no who makes them? What is a good brand of carb?