Loosing prime to one engine

[Larry Catlett]

I have a 1988 10 Meter International Express Cruiser with twin 454 Model 350 Crusaders. I have a problem with loosing prime on my starboard engine. I have replaced the fuel pump, which was over 20 years old, made sure my fuel filter and water separator are tight, replaced the flexible fuel line from the manifold to the fuel filter, tightened all fittings and of course check everywhere for leaks. If the boat sets for 2 or 3 weeks with out starting the prime is gone and no gas at all can be pumped into the carb. We took it from the Potomac River to Nags Head NC in June, 13 hours and some very rough water from Coinjock to Manteo, and the problem started when we got there. I had a spare fuel pump on board and we changed it out and it ran great. When we got back and it sat for 3 weeks it happened again. If I disconnect the fuel line at the manifold, force gas into the fuel line and pour a little down the throat of the carb I can eventually get the prime back and the engine runs great. I have not removed the anti siphon valves to check them and as far as I know they are original.
Any ideas would be appreciated

[Stripermann2]

Sounds like you have the typical Quadrajet syndrome of fuel leaking at of the well plugs on the bottom of the carb. Google Quadrajet leaking well plugs for more info.
It's an easy fix.

[prowlersfish]

X2

[dek4udave]

'Could be the Q-Jet leak-down, but I have experienced fuel pickup hose (wigglers)failure due to Ethanol. The hose becomes soft and expands, admitting air where it attaches to tank fitting (inside tank). In my 8.1 re-powered 1980 F-36, I've gone to copper pickups, because there's no room to clamp these hoses to the receptacle, except maybe 3 or 4 turns of solid 12 gauge copper wire, twisted to tighten.

[prowlersfish]

The pick up tubes should not be hose . The should be the same material as the tank . Although I have seen plastic tubing used . The pick up tube should be ridged . Using something like a hose as a pick up is asking for trouble . Not OEM for sure .


BTW welcome to the Forum