I havn't seen the inside of your motor, but in hondas past the oil pump was driven by a chain off the clutch basket on the transmission input shaft.
Used to be that you could put the pan on, hold the pressure relief valve in with your thumb and spin the pump drive gear with a 10mm socket on a drill. This would be with the clutch basket removed. You can feel the oil pump load up as the pressure builds. I usually wait until I see a good amount of oil running down from the head before putting everything back together. I would typically tilt the motor back on the bench a little bit to keep the oil running back into the pan instead of onto the workbench.
Used to be that you could put the pan on, hold the pressure relief valve in with your thumb and spin the pump drive gear with a 10mm socket on a drill. This would be with the clutch basket removed. You can feel the oil pump load up as the pressure builds. I usually wait until I see a good amount of oil running down from the head before putting everything back together. I would typically tilt the motor back on the bench a little bit to keep the oil running back into the pan instead of onto the workbench.