Yikes!! Fuel in Bilge

[GeoMax]

Launched latest purchase today (1995 Maxum 2300sr, 1995 Mercruiser 5.7 carb with Alpha 1-II. Hasn't been run in two years and ran fine during initial trial and then noticed a fuel smell after 15 minutes, opened engine cover and saw small amount of fuel in bilge. Shut down totally and quickly towed back to shore. It has an aluminum 63 gal tank, all the fittings appear to NOT be leaking (tank, pump, carb, filter). After sopping up the fuel (less than pint) and ventilating I started again with no apparent leak. My question is: with original mechanical fuel pump, could the fuel pump gasket have been dry, leaked under power and needed to swell??? If so I'll obviously replace pump.....but am I missing something?

 

[Fordiesel69]

Re: Yikes!! Fuel in Bilge

A pressure test is in order....... Your tank is alu and may have pits. You may be hitting wake and squeezing out fuel.

I doubt the mechanical pump would do that. Usually the diaphram rips and lets fuel into the line leading to the carb OR floods the oil with fuel......

 

[Webercook]

Re: Yikes!! Fuel in Bilge

You may want to check the fuel filter/water separator. If was sitting and there was moisture in the fuel separator, it could have rusted through causing a fuel leak.

 

[GeoMax]

Re: Yikes!! Fuel in Bilge

Thanks for all the advice and input.
My plan per your suggestions: pressure check the tank (3-4psi), recheck all the fittings and the integrity of the hoses (someone said that I might not be visualizing any small gas leakage because the engine compartment was warm and therefore the fuel was evaporating quickly), replace the mech fuel pump, tighten the carb bolts, and replace the filter. Hopefully I won't have to fix the tank. Oh yeah, make sure the electrical if OFF. I'll let you know.
GeoMax

 

[04fxdwgi]

Re: Yikes!! Fuel in Bilge

Thanks for all the advice and input.
My plan per your suggestions: pressure check the tank (3-4psi), recheck all the fittings and the integrity of the hoses (someone said that I might not be visualizing any small gas leakage because the engine compartment was warm and therefore the fuel was evaporating quickly), replace the mech fuel pump, tighten the carb bolts, and replace the filter. Hopefully I won't have to fix the tank. Oh yeah, make sure the electrical if OFF. I'll let you know.
GeoMax

Suggestion: When pressure testing fuel tank, remove fuel first. If it has a pinhole leak in it and the leak is below the fuel level, you will squirt lots of fuel out before you see any change in the pressure gauge, where as if there is just air in there, it'll show up pretty quick. I had an aluminum tank in an older boat spring a leak on a welded seam. Was a real pain to pull that bad boy out.. After rewelding the seam, the shop epoxy lined the tank. No leaks for the 5 years following while I still had the boat.