Another Carb Question?????

[81 Checkmate]

Ok its me again. Sorry to aggravate you guys becouse it's probly been ask many times. One fellow said to get the auto carb off the boat. The question is what is the difference? Some have said that they have a drain tube in them when flooded they drain back to the fuel pump. is this correct? And i believe this is the only difference that i personly have read about. Can some one fill everyone in on the difference and also can you convert a Auto carb to Marine Carb by adding the drain tube?

 

[Fishermark]

Re: Another Carb Question?????

Some have said that they have a drain tube in them when flooded they drain back to the fuel pump. is this correct?

Not correct.

It is actually the other way around. The clear tube is from the pump to the carb. Not the other way around. If the diaphram ruptures in the fuel pump, the excess gas will go to the carb and not the bilge.


The carb itself needs a j-tube or something similar to catch any fuel that may overflow from a stuck needle valve, etc.

From the Coast Guard regs:

183.526 - Carburetors.

(a) [Reserved] (b) Each carburetor must not leak more than five cubic centimeters of fuel in 30 seconds when: (1) The float valve is open; (2) The carburetor is at half throttle; and (3) The engine is cranked without starting; or (4) The fuel pump is delivering the maximum pressure specified by its manufacturer.

(c) Each updraft and horizontal draft carburetor must have a device that: (1) Collects and holds fuel that flows out of the carburetor venturi section toward the air intake; (2) Prevents collected fuel from being carried out of the carburetor assembly by the shock wave of a backfire or by reverse air flow; and (3) Returns collected fuel to the engine induction system after the engine starts, [CGD 74209, 42 FR 5950, Jan. 31, 1977, as amended by CGD 7798, 42 FR 36253, July 14, 1977]

Read more: http://cfr.vlex.com/vid/183-526-carburetors-19764195#ixzz0uQzX1PA7