[Jeb1971]

I have an 85 evinrude 235.
What do you guys think about using a P4389 Carter electric fuel pump.
It is a marine listed pump, with a 6psi setting. This pump is actually pretty cool.

[tashasdaddy]

if you can rig a safety switch, that cuts it off, when the engine is not running, fine. the problem is if the engine shuts down for some unexplained reason, or the ingnition is left on the pump keeps pumping, possibly flooding the motor, and becomes a major fire hazard. really not recommended. the pump or the fire.

[Dhadley]

If you have insurance don't let them find out about it.

[Jeb1971]

Thanks for your input guys.
The reason that I ask is because I have read posts by others running the motor I have '85 2.6XP. I have read that they have said that sometimes at WOT, they run the carbs dry with the stock pump. I have seen other guys state that they run holley or accell pumps, but I dont to run an automotive pump, hence the pre stated Carter.
thanks

[Silvertip]

Then they get the same warning you did! If there is no automatic shut off its dangerous. On a four stroke its easy to incorporate automatic shut off. The oil pressure switch works fine for that. No oil pressure, no current to the fuel pump relay.

[Jeb1971]

Wow!! . I never thought of that.. Humm

BTW, I appologize, if you saw the other thread I posted with the same question. I forgot that I posted that, and the instant email notification never told me about the responses to it which I do VALUE GREATLY and wasn't ignoring you.

But about this pump, that is a very good point.
I like the idea of running a switch off of the oil psi gauge on a 4 stroke, but seeing that this is 2 stroke, what about this, what about running a 1/2 pound psi switch, NG (normally grounded) off of the cooling water. Then when psi drops below 1/2 psi, simulating a non running motor, it would cut off the circut to the pump?

[Jeb1971]

Originally Posted by Jeb1971

Wow!! . I never thought of that.. Humm

BTW, I appologize, if you saw the other thread I posted with the same question. I forgot that I posted that, and the instant email notification never told me about the responses to it which I do VALUE GREATLY and wasn't ignoring you.

But about this pump, that is a very good point.
I like the idea of running a switch off of the oil psi gauge on a 4 stroke, but seeing that this is 2 stroke, what about this, what about running a 1/2 pound psi switch, NG (normally grounded) off of the cooling water. Then when psi drops below 1/2 psi, simulating a non running motor, it would cut off the circut to the pump?

OOPS!! I just realized that wont work.. Ok, what about a regular 2 pole 1/2 lb psi switch (NOT NG) what was I thinking?

[wavrider]

Electric fuel pump for outboard.

Not a good idea for the reasons allready stated, flooding, fire etc.etc.

If you really going to do this then a cut off is needed with the engine not running. Perhaps you could use the output of your rectifier to a 12VDC relay. this would control your fuel pump and only turn it on when the engine is running. yuo could also run a light off of one pole of the relay if you use a double pole double throw relay to energize a light on your console to let the operator know the fuel pump is energized.

Another idea is to use a single pole double throw switch to turn your fuel pump on for starting purposes, IE fuel pump on to fill carb bowls for first time start of the day. Then turn the switch to the other pole for normal run operation so power is supplied from the running motor electrical system.

Several configurations will work but the best will be the safest so no flooding, or fire potential. Enjoy and be safe,WAV

[Jeb1971]

Thanks Wavrider for your info. I have really been thinking about what you guys have said about the possible flooding and possible expolsion and fire attributed to a startup with a motor full of fuel, and will not run this pump unless I do have it on a switch of some kind.

I had thought of running it off of the wire from the regulator, but since that wire runs to the post of the solenoid which is connected to the battery, then some kind of diode setup would have to be used and thats a little beyond my skill level, atleast at this time.

I am thinking I will run the pump (+) to the accessories post of the key switch and the (-) to a pressure switch on the water circuit, a normally OPEN , 1/2 pound pressure switch.

I was a little confused before about a NG (normally groung) switch.. I actually havent ever heard of one of those.

But a normally OPEN switch will be closed when H20 pressure exhists, hence closing the circut to the pump(when engine is running), and when H20 pressure stops,
the switch will go to open and shut off the pump.
As far as priming for first start, I'll probably just use the 'ol primer bulb.

[wavrider]

IF running to the water then pump would only activate the 1/2 lb pressure switch after the thermostats open, unless you are running the pressure from the tell-tale, then the switch might work.

Use the output from the rectifier before it goes to the regulator for your positive VDC, negative side of the 12vdc relay will run to a switch on the console so you have positive control of the fuel pump, you can disconnect the fuel pump as an emergency cutoff by opening the circuit at the switch, disconnecting the ground so the relay is not energized and no positive VDC to the fuel pump.

This configuration gives two safety features, fuel pump on only when engine running, (output of rectifier),and safety cutoff switch controlled by the operator so fuel can be cut off at any time engine is running.

I do like the idea of using the pressure sensing switch, guaranteed no over heating problems. No water flow, no fuel.

This will keep unnecessary wires from underneath the cowl, not a whole lot of room under there anyway.

You got my interest up on this project, please keep informed of the results. Enjoy and be safe,WAV

[wilde1j]

I have a very simple question: Why???

The stock pumps work fine and don't have any safety issues.