there is a yellow color tygon hose comming off my mechanical fuel pump on my 1988 chris craft with a mercruiser 454. the hose routes up to a full time vaccumm port on my quadrajet. i understand this is a USCG regulation incase the fuel pump were to leak the carb would suck fuel into the manifold thus making the engine run rich to force me to inspect and find that the pump is leaking. it also keeps fuel from accumulating in my bilge and preventing my boat from blowing up. i get it.
my question is this, the current carb has a loose throttle plate bushing so i bought a "marine" quadrajet off of ebay. the old carb has a full time vaccumm port where the tygon hose connects. the new carb just has a tube pressed into the back of the air horn of the carb. this tube is clearly not a vaccumm port. should i hook the tygon hose up to that port? i kind of fugured if the fuel pump were to leak it would need a source of suction to suck the fuel up to the carb. since the new carb just has a tube to the secondaries there is no vaccumm. if the fuel pump were to leak would it pump fuel up to the carb? or does tge fuel need to be sucked up through a vaccumm port?
my question is this, the current carb has a loose throttle plate bushing so i bought a "marine" quadrajet off of ebay. the old carb has a full time vaccumm port where the tygon hose connects. the new carb just has a tube pressed into the back of the air horn of the carb. this tube is clearly not a vaccumm port. should i hook the tygon hose up to that port? i kind of fugured if the fuel pump were to leak it would need a source of suction to suck the fuel up to the carb. since the new carb just has a tube to the secondaries there is no vaccumm. if the fuel pump were to leak would it pump fuel up to the carb? or does tge fuel need to be sucked up through a vaccumm port?
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