Ok, didn't get the little 444 Jd but got a 644C instead. Rebuilt engine starts instantly. But it has leaks around the square glass fuel filters. I've read that the metal ones won't leak but also read the metal ones won't fit. Also needs a couple of pumps on the primer after sitting overnight. Read there is a check ball in the elbow fitting by the fuel filters? Haven't got it home yet but really looking forward to it!
Per the parts catalog, (see screenshot below) the metal fuel filter subs for the glass one. The check valve is highlighted in the same screenshot. The check valve can be disassembled ,maybe a piece of debris stuck in it.
I believe the glass filters can leak due to the slightly higher fuel pressure produced by the transfer pump mounted on the inline injection pump compared to a cylinder block mounted transfer pump.
Try cleaning the oring area on the filter base really good. There is usually some type of buildup in those areas. Make sure the orings on the filter are clean.