1952 D47U will not start on hill.

Hi all,haven't run my D4 for several months so I lubed it up ,started the pony (after a stuck float issue) and ran it out back to clean up my fire road. Ran fine for several hours then while dragging the road down hill in reverse I hung up on a small oak and killed the engine. My E-Brake is median at best and the tree was holding me in place so I fired up the pony and tried starting the main for 30 minutes with no luck. There was a flat spot in the road a few hundred feet down so I cranked up the pony,engaged the starter clutch ,released the E-Brake and put the tranny in reverse and pulled the clutch. It only took a small nudge to push over the oak and releasing the main clutch I was able to freewheel coast the D4 to the flat spot. I checked all the water and oil levels and let the D4 rest for about 2 hours . I came back to it later, fired up the pony and the main fired right off. So my question is why would the D4 not start on the hill? Was it because the fuel tank (Seat Tank) was lower than the engine or do I have another issue? It was also a very hot day,102 degrees,could that be a factor? Thanks for any ideas. Don

Can't help you a lot it is flat around here. Friends in the Idaho hills told me they were always very careful to stop the D6s on a flat spot(quite a challenge on their farm) or they would not start. From memory it was the pilot motor that was the problem. Flood one cylinder and no fuel to the other or something similar.
cheers wimmera farmer

If I could have gotten it to coast for a couple of hundred feet, I would have tried bump starting it. It is possible that for some reason your supply pump couldn't supply the injectors???

The pony runs real fast so I can not see where it would not supply enough fuel to start it up unless the pump has to be level to work at it's best. I usually always stop on a flat spot then shut down the main but sometimes I guess "Stuff Happens" and pilot error kicks in,could be the Corona factor lol.Thanks for your replies and keep on tracking!
Don