Electric fuel pump power source

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Kcu320

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I am installing an electrical fuel pump on a 1978 Sears GT18 powered by a twin cylinder 18hp Onan. I haven't taken apart the mechanical fuel pump to diagnose its issue. I have just decided to install the electric. I wanted to have power to the pump just before running so I thought I would tap into the solenoid to the starter. I grounded to the frame. When I turn the key to accessory nothing happens; as I expected. You need to turn the key to start which is one more click over. However, nothing happens there either. No sound or anything. Perhaps I didn't chose wisely as a source of power. I would like to know how others were successful. I also read that these electric fuel pumps are not good at pulling the fuel but are better at pushing the fuel. I have the fuel pump roughly the same height as the fuel tank (which is in the rear of the tractor under the seat). I may have to lower it more. I also have the fuel pump positioned vertically instead of horizontally. I'm starting to wonder if that would be a problem as well. First and foremost, though, is what should I hook up the power source to. I do have the schematic which I have attached. Thanks for your assistance.
 

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Wire up the pump so it's getting power when you turn the switch to ignition. If the fuel tank outlet is on the bottom position the pump so it's near the bottom of the tank. If it comes out the top still position the pump near the bottom so maybe it will get a siphon effect and push the gas to the carb. Some electric pumps develop too much pressure which can cause flooding. Wouldn't it be easier to just replace the pulse pump?
 
I have one on my FF24 Onan, it's mounted on the side of the engine near old vacuum pump. It's wired through ignition and then through a switch, not really looked to see how previous owner wired. I maybe able to check it in a few days after some of the snow melts off of it.
 
ol' stonebreaker said:
Wire up the pump so it's getting power when you turn the switch to ignition. If the fuel tank outlet is on the bottom position the pump so it's near the bottom of the tank. If it comes out the top still position the pump near the bottom so maybe it will get a siphon effect and push the gas to the carb. Some electric pumps develop too much pressure which can cause flooding. Wouldn't it be easier to just replace the pulse pump?
Click to expand...
 
I must have wired it wrong. I’m going to back up and take the Onan fuel pump off, intake manifold and carb and clean them all up with an ultrasonic cleaner. I saw a YouTube video about carefully bending the reeds and reassembling with a clean carb. Hope that works.
 
Be caareful removing the intake bolts, they have a tendency to twist off. Ask me how I know!! On reassembly use antiseize on the bolt threads.
 
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