poulan pro 42cc

Have poulan pro 42cc ... does anyone know the min and max rpm settings for this saw? thanks

Hi folks, I have a poulan pro 42cc. It starts fine but then rpm starts fluctuating (external tach attached). It’ll go from (for example) 2500 up to 2700 drop back again then up to 3800, back to 2700 and so on. (Not touching throttle). If I turn it on it’s side (ie chain running horizontal)...