Note that the Mercarb looks like a Rochester 2-Jet (2G) carburetor, but is actually a completely different unit. Only the float is common to the two carbs. The Mercarb can be distinguished by the lack of 'Rochester' or 'Two-Jet' markings, which all 2G carbs have.
Please note that there are two different Mercarbs. The one serviced with this kit (CK819) has an accelerator pump with a 5/8" diameter cup and a straight stem.
The other type has a large pump cup with a bent stem and takes our kit CK816.