OEM fuel pump, or Aftermarket ?

[johnnymag3 2,437]

I believe my fuel pump on the 312 Hydro is shot. I cleaned all of the lines, and checked the float in the carb.....carb was spotless. New last year.

  I also changed the fuel filter which also was spotless. If I run the engine in part choke,it will run fine, but the filter is empty, If I pressurize the fuel tank and fill the Fuel filter, it will run fine until the filter empties..My guess is that under no load and low RPMs, the engine vacuum with partial choke is pulling enough fuel into the carb for the engine to run.

any suggestions with regards, to the longevity of Aftermarket Pumps, vs. OEM pumps?

 

thanks for any and all input from you guys

 

John

 

 

[953 nut 51,532]

Have you taken a look at the screen filter in your gas tank to be sure it is clear? Fuel filters are seldom "full" but are passing a sufficient amount of gas to operate the engine. Have you replaced the rubber fuel lines, a slight pin hole would allow air to be sucked by the pump more easily than gas. Are you running ethanol free gas, ethanol will destroy your fuel system.       https://www.pure-gas.org/

[JoeM 7,608]

I've used both with no issues. The after market one is running 2 years now.

I've also installed electric, but only the Mr. Gasket brand. works good too.

[johnnymag3 2,437]

I did blow small pressure from the fuel line to the tank.....BIG BUBBLES .!!!!

and I use non ethanol now, but unsure of first owners........filter has no fuel in it when running, unless I blow into the tank

[johnnymag3 2,437]

should I pull pump and test it?

[johnnymag3 2,437]

Kohler Magnum 12 engine...common fuel pump

[dells68 7,494]

Go with the electric pump.  I've got one on my 312 and she starts easily with a turn of a switch every time!

[johnnymag3 2,437]

What type of electric pump? don't we need below 2 psi. for our seat to seal? and what about return lines after the bowl is full?

 

Thanks, John

[johnnymag3 2,437]

Is there anyone here on this site that sells fuel pumps?

 

Thank you, John

[dells68 7,494]

The pump I used is a low pressure pump.  No need for a return line, as they will start almost instantly and I don't think the pump would push enough pressure to overpower the float valve.

[Skipper 1,788]

Yeah, I have installed quite a few low pressure pumps, and you just put them inline. No need to run returns etc. Just hook them up so they run when you have ignition on, and that's it. I have used the 10$ version several times too without any problems. Quite frankly, I do this conversion on all tractors i have come thru that has any kind if issue with the pump, and I also do it on every one of my own machines just as a preventative measure.

Edited July 11, 2018 by Skipper

[953 nut 51,532]

This one is $ 8.50 shipped to your house, found on Ebay. I am running a few of them and have had good results.

  HEP-02A New Gas Diesel fuel pump Inline Low Pressure electric fuel pump 12V

Be sure to mount the pump lower than the tank, great pushers but lousy suckers!

[johnnymag3 2,437]

ok, so the questions are still on the table......My tractor will run perfect until the fuel filter empties........Float is down in carb, and it still wont get fuel. Engine spits and sputters, pops and backfires....then I wait and start again in a minute or two, then it runs fine. If I leave the choke half open it runs fine forever   at any speed. Do I have a blockage in the carb? I took off the fuel pump and manually tested it....it sucks and pumps as normal. The fuel in the tank is new, the lines are new, the screen is clean in the tank, the shutoff is open fully, I am at a loss for more things to look at?

 

Thank You...............

HELP

 

John

[johnnymag3 2,437]

oh, I forgot to mention the needle and seat are fine also,

 

[wildfire305 58]

I had fuel issues after some water got in the tank. The cap was bad and it sat out in the rain for a day. The fuel pump died a few hours of use after I got all the water out of the system. Bought a new cap and also Bought new replacement pump - not impressed with the pump. Didn't run right at all. It turned out that the arm was 1/4" shorter and only engaged the diaphragm half way through the stroke. I got a refund for it and decided to use my noodle. I gutted the brand new pump of all the mechanisms, cut the metal disc out of the diaphragm, capped the outlet to the carb and basically created a Crankcase pulse adapter out of the pump. Then I installed a mikuni style plastic pump zip tied on the old one with the pulse port hooked up to my "adapter". The air cover hides all of it and it has been very reliable for 20 hours now. It also only cost me $10. I had previously replaced the fuel lines. 

[wildfire305 58]

After doing all of this, I found out that Taryl Dactal has a YouTube video showing the same thing. Apparently, the replacement Kohler fuel pumps (even genuine) are not exactly reliable nowadays. The mikuni style is used on everything from quads, generators, dirt bikes, zero turns, etc. And doesn't require electricity. It also won't be dumping fuel if your engine dies and your not within arms reach to shut off the key. 

Edited July 19, 2018 by wildfire305
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