RavenII is a bit tricky to start but i teach all my students the same ... as per POH... 3-5 secs prime with mixture full rich, pull mixture out, starter engaged and LISTEN the engine.....when it starts firing mixture full rich and release starter
I think its the sequence and how you treat the start up list that Robinson factory has produced
Works for me!! Dont try to re-invent the wheel ....it doesnt say anywhere 10 or 15 secs priming
Whats the point of that? Its a fuel injected engine.
H-M