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Chrysler 70 h.p. Outboard fuel supply difficulty.

boatdokker

Regular Contributor
This is a 1969 Chrysler 3 cylinder, 70 h.p., outboard motor and the motor is having some difficulty at idle. The motor will start after spraying the
carburetors with either carb. cleaner or engine starting fluid. The motor will then shut down. If the boat gas can is elevated above the fuel pump, the
motor will continue idling. The outlet line to the carburetors was disassembled from the motor, and if the motor is cranked over, only a trickle of fuel will
flow out of the fuel line. This means to me that the factory mechanical fuel pump isn't any good and the gasket and pump diaphragm assembly look fine.

What are the options for going to a low pressure electric fuel pump. What is the recommended psi for that kind of fuel pump? What about getting a fuel
pump from "Autozone" and installing a regulator right before the carburetors?

Thanks, "boatdokker"
 
Adding an electric fuel pump is like adding a bomb to your system(my opinion).
You'd need a 2-3 # pressure pump.
Any more then the needle/float will be overpowered and flood the motor.

The pump when activated works continuously until the powers turned off.

Figure out why the pump isn't working??
Post a pic of the pump.

Compression test?
Replace the hoses and if there's a gasket between the pump and block replace that too.
 
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There are 12v electric fuel pumps that will operate in the 3 to 6 psi range. I'm hoping that I can install an inline fuel regulator and adjust the fuel pressure to the
2 to 3 psi range. This is a photo of the factory fuel pump that is installed on the motor. The pressure lines have already been replaced. The gaskets seem o.k.
P1010150.jpg
 
I got a low pressure 12 volt HEP-02A fuel pump and installed it with fuel filters before and after the fuel pump. I also switched from 1:30 ratio fuel to 1:50 fuel. I had to swap out the fouled spark plugs and then installed Champion L77JC4's. The motor then started and I adjusted the fuel pressure to about 3 to 4 psi with an inline valve installed after the fuel pump. With the valve only slightly loosened, the system does not leak and can be controlled with a toggle switch. Thanks for your advice. W.R. "boatdokker"[h=1][/h]
 
Should make sure that pump stops when motor is NOT TURNING .-----Look into why that simple / reliable factory fuel pump is not working.
 
Yeah...I agree...thanks. That motor wouldn't even kick over when I got it. The points and spark plugs had to be replaced. Thanks very much. W.R.
 
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