I doubt very much that opening the tube to the top would lose the prime. Not unless it was over a very long time.
The distributor should come straight up. You may be on to something there. Perhaps there is some problem in the belly of the beast.
The reason why I suggested the drill over simply turning the screwdriver is so that you can see the oil run up to the top end. If the system is dumping the oil somewhere else it is better to figure that out with the drill than with the engine running.
|