mariner 100 hp 198? 2 stokes 4 cyl. ,4 carbs,,I have the bottom carbs leaking,i rebuild all carbs pressure test the needles no leaks,i install all on engine prime them and the 2 bot. carbs leak from the small tube in the ventury,it pissing out ....the 2 top one(1&2) are good,but carb 1&2 have idle screw,and the #3  dont have screw ,,cap in place of screw,,...Sorry for my English, is it normal to have only 2 mix screw
on that engine,???
on that engine,???