Cessna 150
Flight Crew Commercial; Flight Crew Instrument; Flight Crew Multiengine
Flight Crew Last 90 Days 41.8; Flight Crew Total 320.6; Flight Crew Type 2.0
Aircraft Equipment Problem Critical
Flight Crew Diverted; Flight Crew Landed in Emergency Condition
Aircraft
Introductory flight in C-150B.  After one full-stop taxi-back landing; and one touch-and-go; proceeded west-south-west of the field for maneuvers.  After clearing turns; steep turns; one chandelle; one power-on stall; and one power-off stall; upon power application during power-off stall recovery; the engine produced only partial power.  Carb heat was applied during low-throttle and idle-power maneuvers.  Pilot not flying noted engine not making full power; and began pumping throttle; this restored some power temporarily.  I (pilot flying) checked and adjusted mixture to full-rich; cycled carb heat from ON to OFF to ON; and began turning towards an airport.  It became apparent the remainder of the flight would be at partial power; so we chose to make a precautionary landing on an available dirt road in our vicinity. Landing on road was normal (full flaps; smooth touchdown; full braking to a stop).  Engine remained at partial power throughout approach and continued idling after landing until we shut it down.  We kept the fuel ON since the engine continued to run; and we preferred to have the option of using the partial power remaining.  There were no injuries; property damage; or damage to the aircraft.
C-150 pilot discovers after performing some basic flight maneuvers; that the engine will only produce partial power. A landing on an available dirt road is chosen as the least risky option and accomplished successfully.