I've got a Zama carb off a blower. It measures 13mm on the intake port side and on the outboard side it starts at 16mm where the choke butterfly seats and narrows to 9mm about a fourth of the way into the carb block.

Which is the correct place to measure for determining the carb's size?

Thanks.

I'd go with the smallest diameter.

Dr.1

Me0,
The size of the carb determined by the diameter of the venturi. In this case this is the 9mm section. Walbro's have a number in 64ths cast into the inlet side and Zama's don't.

Dave