Carb heat/ mixture
I was very nervous of the carb heat assist on some of my training 22's and tended to pull more.
I can't imagine a problem with excessive carb heat other than coming into the hover at high weights/ Density Altitude and forgetting to push the heat back in.
I was taught to push it in at around 300ft but felt more comfortable doing so much later, for reasons that should seem obvious to any operator of normaly aspirated engines.
Constant hot air is nothing new - I have Gipsy powered vintage fixed wing machines that operate in hot air at all throttle settings other than fully open - never a carb ice problem or even consideration in normal use.
Mixture - I cant imagine anyone leaning the mixture on a heli and feeling happy about it.
To lean an engine properly requires the pilot to find the 'lean of peak' setting. Whilst this will cause an engine driving a propeller to just splutter and cough it will stop a Robbo engine dead.
Touching the mixture is therefore tempting fate?
Happy with my choice of injected Raven 2 (despite not really needing the extra performance and having to cough up an extra $50k over the Raven 1...)
Hairyplane.