Panic - the type 228 comes in several throttle body sizes. The different venturii are selected along with the proper throttle body size. And I agree, just changing the venturi without making other changes would not be a way to do carbs. Zeniths are not done in that manner.
I haven't really studied the information on the website, as I have been a Zenith dealer for probably 40 years, and have access to more information than is probably on the website. Have sold several hundred, perhaps more than a thousand, Zenith carbs over the years.
Jon.
Last edited by carbking; 08/21/2019 2:23 PM.