1989 312-8

[william orndorff 7]

I have a question about the fuel pump on my 312-8. I had trouble starting it last week so I replaced all of the fuel lines with tigon tubing, I cleaned the carb and put everything back together. It fired right up as soon as the fuel hit the carb and ran great. This week is a different story. My fuel lines are clear so I can see fuel from the tank going thru the fuel filter and coming within 2 inches of the fuel pump (my pump is mechanical).Fuel is not making it all the way to the pump. I don't have any fuel leaks and brand new lines. Is my fuel pump bad ?  Also does my fuel pump act as a check valve to prevent fuel from draining all the way back to the  tank?

[peter lena 9,280]

William i had a similar issue with mine , i picked up 3 aluminum check valves on  amazon for the herd , installed it closest to fuel pump , at the rise coming up from frame to pump, result ?  instant start . it was  12 $  no shipping , pete

[Sarge 3,465]

Either the float is stuck shut, or the pump has dirt in it and not allowing the valves to seat and create the suction necessary to pull the fuel the rest of the way through. You can try pressurizing the tank a bit with your mouth and the tank at around half full to prevent getting a face full of gasoline. I don't recommend using an air hose as it is really easy to blow the tank seams. Once primed, most pumps will clear debris on their own - if not, search out the pump rebuild kit and clean/rebuild it carefully. Pay close attention to how the valves sit inside the pump - they only work correctly in one orientation.

 

Sarge

[oliver2-44 10,734]

Yes, the valves in your mechanical pump will act as check valves when there in good condition.  Sometimes they just need to be disassembled and cleaned, sometimes they need replacing.  Disconnect the line on the outlet of the pump or at the carb and crank the tractor. If it primes and pumps gas out, then reconnect line and see if tractor will start & run.  If it runs, that means pump is working, but valves might be gummed up.  Then I would disassemble pump to clean it, or run some Seafoam in gas for a while.  

[oliver2-44 10,734]

Here a thread showing the crud in a pump of mine. It still pumped so/so. There's also a diagram of how the valves go in the pump, yes I got them mixed up! 

 

[william orndorff 7]

Thanks for the help men. I'm going to try to clean up the pump.  On the chance that doesn't work where can I find a rebuild kit?

[ebinmaine 72,725]

18 hours ago, william orndorff said:

Thanks for the help men. I'm going to try to clean up the pump.  On the chance that doesn't work where can I find a rebuild kit?

Then and now.

 

http://www.then-now-auto.com/kohler-fuel-pumps-2/

 

[953 nut 60,080]

The fuel pump is a good pusher, but they don't do a great job of drawing a suction. If the fuel tank is full you will have better luck.