bvgs
All but 1 hour of my flying so far has been on the R22 but that 1 hour was in an R44 raven II. I clearly remember the instructor ( one of Heli-Air's high hours team on R44's) letting me do the start and making me prime for
10 seconds but otherwise following your exact proceedure described. It started with no problem.
What does the POH say?
Try 10 seconds and see?
Good luck.
Ian.