1979 Marktwain inline 6 cyl, 165 hp low flow fuel pump

[moffitt77]

I cleaned the fuel pump last year and replaced the fuel filter. Now when I take off the fuel line going into the pump there is no fuel coming out. The fuel shut off switch is not plugged. I thought that there should be if I remember correctly. I have 3/4 tank of gas. I know the manual says to plug the fuel line after disconnecting to avoid fuel siphoning into the well. The line isn't plugged as I can blow air through it into the tank.

 

[Failproof]

Re: 1979 Marktwain inline 6 cyl, 165 hp low flow fuel pump

Whats the question? If your worried because it didnt self siphon, it will not happen every time. If you have a top feed tank. If its a side feed (with fuel above outlet) or bottom feed, then yeah, it will GRAVITY flow if tank is above line end.

 

[moffitt77]

Re: 1979 Marktwain inline 6 cyl, 165 hp low flow fuel pump

The gas line goes into the top of the tank. I thought that since it self siphoned last year that it would again this year.

 

[Failproof]

Re: 1979 Marktwain inline 6 cyl, 165 hp low flow fuel pump

If you have no check valve, and you had a line FULL of fuel, and it was open, below level of fuel in tank, it is then feasible to start self siphon. But one little air bubble to break that VACUUM, and no self siphon.

 

[haulnazz15]

Re: 1979 Marktwain inline 6 cyl, 165 hp low flow fuel pump

I'm really not sure what the question is? I understand the siphon idea, but the actual "end" of your fuel line is at the carburetor inlet. So the fuel level is never above the carb inlet except possibly in the full-tank of fuel.