From your post I guessed you fly a Raven I. The Raven II has similar problems starting ie. engine flooding and little reaction from the starter motor, the difference being it happens when the machine is hot.
Recommended to prime the engine with mixture full and Magnetos off, full throttle for around three seconds before trying starter for another 3 seconds.
Then close throttle and follow the Robinson manual start-up procedure. Haven't tried it yet....will report on success rate
