fuel supply drains away after a few days needs priming to start

mowermaint

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  • / fuel supply drains away after a few days needs priming to start
Hi folks, new forum for me.
I have a JD riding mower the E series. Has the 16 hp 2 cyl Kawasaki engine. I had some old gas that I had to clean out of it. Ultimately I took apart the carb and got things going again. Problem I have now that after using it and parking it the gas must be draining back to the fuel tank. I wonder if in the fuel filter/line there is a drain back preventer valve or some such? If I spray some raw fuel into the carb I can get it going after several squirts. But then a few days later same thing. So it appears that the fuel is draining back into the tank. I don't see fuel puddling in the fuel filter. I did not rebuild the fuel pump so if there is some anti drain back in there that could be the problem. I thought I'd ask first before launching into that fuel pump. I don't think that its simply leaking out of the fuel bowl as I see no signs or smell raw fuel. It could be a very slow leak that I am not noticing.

I've worked on all kinds of engines, boat to diesel, but this is my first experience with a carb with that electric shutoff valve in the bottom of the bowl. Is it common for it to drain out there?
 

slomo

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  • / fuel supply drains away after a few days needs priming to start
Drop the carb fuel bowl. Also remove the fuel line where it connects to the carb. See if you have flow from the tank. Use a good fuel filter and shut off valve.

On the fuel cut off solenoid, I remove the bowl and snip that plunger off. This defeats the solenoid and will start every time. Yes it can leak from there. Remember when it get's hot outside, the fuel will slightly pressurize the tank and lines when it expands.

slomo
 

bertsmobile1

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  • / fuel supply drains away after a few days needs priming to start
All that the solenoid does is ram a plug up the end of the main jet so in those 1/2 dozen revolutions from the time you turn the engine off till the time it stops revolving no fuel is drawn into the engine & blown out the exhaust without being burned. This unburned fuel may or may not ignite in the muffler and cause an explosion, cutely called an "after fire ".
That is all it does.
The fuel pump has a check valve on the out let side.
Occasionally these can fail particularly if the filter is on the carb side of the pump and not the tank side of the pump where it should be.
 

keakar

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  • / fuel supply drains away after a few days needs priming to start
Hi folks, new forum for me.
I have a JD riding mower the E series. Has the 16 hp 2 cyl Kawasaki engine. I had some old gas that I had to clean out of it. Ultimately I took apart the carb and got things going again. Problem I have now that after using it and parking it the gas must be draining back to the fuel tank. I wonder if in the fuel filter/line there is a drain back preventer valve or some such? If I spray some raw fuel into the carb I can get it going after several squirts. But then a few days later same thing. So it appears that the fuel is draining back into the tank. I don't see fuel puddling in the fuel filter. I did not rebuild the fuel pump so if there is some anti drain back in there that could be the problem. I thought I'd ask first before launching into that fuel pump. I don't think that its simply leaking out of the fuel bowl as I see no signs or smell raw fuel. It could be a very slow leak that I am not noticing.

I've worked on all kinds of engines, boat to diesel, but this is my first experience with a carb with that electric shutoff valve in the bottom of the bowl. Is it common for it to drain out there?
replace the fuel pulse pump, it has a check valve to prevent a back suction, so thats your problem
 

slomo

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  • / fuel supply drains away after a few days needs priming to start
All that the solenoid does is ram a plug up the end of the main jet so in those 1/2 dozen revolutions from the time you turn the engine off till the time it stops revolving no fuel is drawn into the engine & blown out the exhaust without being burned. This unburned fuel may or may not ignite in the muffler and cause an explosion, cutely called an "after fire ".
That is all it does.
The fuel pump has a check valve on the out let side.
Occasionally these can fail particularly if the filter is on the carb side of the pump and not the tank side of the pump where it should be.
Good to know Bertsmobile1. Don't forget to tell everyone, when they fail your mower will not start.

slomo
 
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