First of all, get rid of the fueling valve and use T fittings and fuel dots. The fueling valves cause lots of issues.

It also sounds like the glow plug battery is weak, but not sure.

Prime the engine by running it at full throttle with the starter and NO glow plug ignitor for 10 to 15 seconds, go to 1/4 throttle, connect the plug battery and hit it. It should take right off.