Help identifying v4 johnson

Eddie1920

Seaman Apprentice
Joined
Jun 21, 2007
Messages
47
The 90, 115, and 140 all used different Carbs. While on the outside, they may have looked almost the Same, rest assured they were not. Jetting, Air Bleeds and other differences in Fuel Delivery Circuits, as well as Venturi and Throat Sizes. Also, putting Carbs from a 115 or a 140 on a 90 only resulted in a 90 with the Wrong Carbs. same went for the pre 85 115, 140 carbs didn't turn it into a 140
can i measure the bore of the carb throats to determine which carbs they should be 115, 140 etc
 

Eddie1920

Seaman Apprentice
Joined
Jun 21, 2007
Messages
47
im looking at the carbs again more in depth this time. i cannot read the size of the main jets however they are quite large visually, its has a #36 jet in top of each carb throat and in removeable bowl it has 2 jets that are positioned vertically #25 and 2 jets (the largest of all) positioned horizontal which must be the mains and i cannot read any numbers on them, the bore of the carbs where they mate with the intake manifold are 39.2mm
 
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