Electric fuel pump on carb motor

The purple wire to the + post on the coil should be coming from the ignition switch which feeds 12V to the coil and alternator, so it should also support powering the choke heater. Either way, the electric fuel pump really should have the three-way oil pressure switch that @hughespat57 mentioned back in post #2. That way, the fuel pump will run while cranking, and again once oil pressure is developed.
78b58852-e876-4c11-8c76-72c03beb0423_502+carb.jpg

Unsure why someone would run a braided hose from the fuel separator to the carb, other than it looks cool. If approved; fine. If not, please get something back in there that is. When your boat catches fire, you can't just pull off the side of the road and step away as it burns to the ground. Yes, I'm sounding like a broken record...
 
Okay.... I will weigh in. For the record I have two marine Holley 800s with electric Holley Fuel pumps (and Safety switches) in place and working. The system starts the same every time with a turn of the key(s). (One/two pumps for a cold start.)

From the photos (which were very helpful) there are a few obvious issues that probably have nothing to do with the starting experience that should be addressed.

First is the wiring. This diagram is for a Holley Electric Fuel Pump Safety Switch. It manages the initial start of the pump and cuts it off if oil pressure drops. It is simple to install and basically means that if you lose oil pressure the engine and boat won't fill with fuel and go boom.

opss1.jpg


It is easy to run a wire back to the ignition switch and wire it properly. Using the coil wire is just not a good idea since the draw on the fuel pump since it draws 2 amps or so which will affect the coil and potentially other systems.

The fuel line..... While my colleagues don't like braided fuel lines since most are not USCG certified......they have been used for decades in go boats. The issue is one of permeability of the hose itself and of course ethanol. The pressure is not the issue since the pump only generates 6-7 psi.

The wiring and the fuel hose while problematic are likely not the operational issue. The operational issue is the carb. The previous owner was most likely right when he indicated it started "every time". The problem with Edelbrock, Weber and Quadrajet is that they leak down with age. Their design allows fuel to bleed in to the intake manifold when the engine is off or hot which means that it is difficult to start when cold and when hot, the engine is flooded with fuel. Both create a miserable and unpredictable starting experience.

Rebuilding the Edelbrock may help but I just haven't had a lot of luck with that design. The Holley design uses a two bowl design (greater than 600 cfm carbs) fore and aft on the carb. The fuel stays there waiting to be used.

Cold Start:
1) I advance the throttle one or two times fully.
2) Turn the key......fuel pump is switched on and crank the engine. The fuel pump fills the fuel bowls and stabilizes the fuel pressure. The safety switch sees oil pressure and manages the fuel pump.

Hot Start:
1) Turn the key and the engine starts. The fuel pump fills the fuel bowls and stabilizes the fuel pressure. The safety switch sees oil pressure and manages the fuel pump.

Hope that helps.
 
PlayDate said:
The fuel line..... While my colleagues don't like braided fuel lines since most are not USCG certified......they have been used for decades in go boats. The issue is one of permeability of the hose itself and of course ethanol. The pressure is not the issue since the pump only generates 6-7 psi.
.
Click to expand...
But the most important part is the USCG/SAE fuel line has a fire rating. If one should have a situation requiring an insurance claim it may be denied if they can hang it on something non-compliant. Same thing if improper wiring contributed to an issue. I'm just so gun shy on insurance these days.
 
ttmott said:
But the most important part is the USCG/SAE fuel line has a fire rating. If one should have a situation requiring an insurance claim it may be denied if they can hang it on something non-compliant. Same thing if improper wiring contributed to an issue. I'm just so gun shy on insurance these days.
Click to expand...

Yes....and I made both points and feel they should be addressed but they have little to do with the operational problem he has.

In regards to insurance......the house wins most of the time. They are not in business of paying claims....they are in the business of managing risks/claims. In the last 20 years I have spent at least $20k on boat insurance and have never made a claim. In other words .....there is $20k of profit with virtually no cost against it for the insurance company.

The only reason it costs $1-1.3k a year is because of the $500k liability insurance for the marina. It isn't for the boat which has an agreed value of $75k.

A number of marinas are requiring a Safety inspection as part of the annual lease. The inspection has to be performed by a certified marine surveyor. In the case of the OP.....those safety issues would be flagged and would require remediation to get a slip.
 
And there's really no reason to have (what looks like) a filter on the output side of that pump, especially if that output goes right into the water/fuel separating filter. The.re should be one and it should be located on the input of the pump to protect the pump from debris
 
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