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outlawinil 01-12-2003 01:51 PM

Carb fuel bowl siphoning
 
Has anyone tried an inline electric fuel pump to push fuel up to the fuel bowl on the carb for faster startup? Trying to save cranking time. Im talking the 502 carb version. If so what did you use and where can i get some?

mcollinstn 01-12-2003 02:14 PM

Sure.
Carter pump.

Under normal circumstances, though, your motors should fill the bowls within 10 seconds of cranking. Crank one ten seconds. Crank the other ten seconds. Pump throttle on first one four times - crank six seconds. Repeat for other motor. If one or both dont fire, repeat.

with an e-pump, start pump - run it five or ten seconds - pump throttle four times - crank for six seconds - repeat pump and crank procedure...

Dennis Moore 01-12-2003 03:55 PM

Electric fuel pump
 
What I have found is that the fuel is usually evaporating from a hot carb after the engine is shut off. Blocking off the exhaust heat crossover passage and adding an insulator between the manifold and carb will help keep the carb cooler. Mercruiser recommends letting the engine cool off by idling it for a period of time before turning it off. Running the bilge blowers is also helpful.
Adding an electric fuel pump almost always requires adding a fuel pressure regulator or the additional fuel pressure will overwhelm the needle and seats at an idle creating a rough idle condition (the venturi boosters will drip raw fuel at an idle).
If you do add an electric fuel pump make sure it is the kind that circulates the fuel through the armature to keep it cool. A racing fuel pump with an air cooled motor will not last very long (maybe only a season or two).

Dixie Doug 01-13-2003 10:26 AM

Re: Electric fuel pump
 

Originally posted by Dennis Moore
What I have found is that the fuel is usually evaporating from a hot carb after the engine is shut off. Blocking off the exhaust heat crossover passage and adding an insulator between the manifold and carb will help keep the carb cooler. Mercruiser recommends letting the engine cool off by idling it for a period of time before turning it off. Running the bilge blowers is also helpful.
Adding an electric fuel pump almost always requires adding a fuel pressure regulator or the additional fuel pressure will overwhelm the needle and seats at an idle creating a rough idle condition (the venturi boosters will drip raw fuel at an idle).
If you do add an electric fuel pump make sure it is the kind that circulates the fuel through the armature to keep it cool. A racing fuel pump with an air cooled motor will not last very long (maybe only a season or two).

Don't forget to add a low oil pressure shutoff to the pump

RumRunner 01-13-2003 12:28 PM

Two things:

1) Cranking the engine over before it starts will at least get the oil to start pumping before the engine fires up to idle RPM (Yes a pre-lubber would be better)

2) Any time you install an electric pump on a marine application as either the primary or back up pump you're going to want it to go through an oil pressure switch (so that it will not run if the engine has no oil pressure)
This is something you'd want to do for both safety, and legality issues.

Doug

Fast Forward 01-14-2003 05:34 AM

If you decide you would like to install an electric fuel pump let me know. I have a new Mercruiser electric fuel pump still in the box I'd let go at $85 including shipping. I beleive it was $149 at the dealer.

Thanks Brian

blown1500 01-14-2003 04:59 PM

Thanks, RumRunner,
I agree and I know you are up on the subject better than I am !!


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