1975 70hp 3cyl Johnson Carb issue

[Jvickroy1013]

Hey guys, Had this boat working on it for a while now. I re did carbs with total OEM overhaul kit and cleaned very well. When priming the fuel bulb it doesnt prime top carb from what i can tell and is blowing air outthe brass tube running up from fuel bowl too the air intake of carb. What would cause this? Whats crazy is The upper and lower carbs are same part number with the center being different, I swapped lower carb too top and put top on bottom and it continues too do same thing at THE TOP.

 

[racerone]

Are the part numbers different because of the linkages ????-----All 3 carburetors work exactly the same way !

 

[Jvickroy1013]

The center one is different because that is where the fuel feeds in from pump then theres a outlet that feeds the other two carbs off the center. So it has the inlet port on it is why it is different.

 

[ct1762@gmail.com]

what jvickroy said... the only way to get fuel into it is from the middle carb. How are you priming fuel into it now, just by the smaller 5/32'' fuel connector on the top carb? Is the fuel manifold missing? you need a 5/16 to 5/32 reduction tee... should be around there somewhere

 

[Jvickroy1013]

Fuel manifold? I have the small line off center carb with a T in it going to upper and lower carb which is how it was before I got boat