This same issue happened before I put the new motor in. Same carburetor. Mechanical fuel pump with an electric backup.
It seems to happen after driving 25 minutes or so, then stop for several minutes (with motor off or left on). I begin driving again and within minutes it acts like it’s running out of gas. If still moving good I can flip the electric pump on and it seems to catch up and do fine , even after turning the electric pump off.
The last time it stopped I was at a stop sign & I pulled off the road & started checking things. The fuel filter had very little gas in it. Gas pours out of the gas line if I remove it from the tank.
I had the electric fuel pump running (it’s between the carburetor & the mechanical fuel pump. No gas was coming out. If I suck in the line while the pump is running I can get enough gas in my mouth to spit out.
A young man stopped to lend assistance. We figured the out line from the mechanical pump was getting air at the pump. The 99 degree elbow was loose. It’s just in a bad position to have it tight.
I turned it tight as it would turn with the electric fuel pump on & turned the motor over. It began pumping gas.
So I reason that it is losing prime due to a leak at that elbow. I can’t tighten it any more. So I put permatex gasket maker over the threads. I drove it last week & it did the same thing. I got home by turning in the fuel pump again until it started running again.
Can someone have other ideas for me ?
