THE INSTALLATION OF AN IMPROPER DESIGNED INTAKE TUBE AND AIR FILTER BY THE NONMECHANIC RATED PILOT-IN-COMMAND, WHICH RESULTED IN MOISTURE BUILD UP AND COLLAPSE OF THE AIR FILTER, WHICH RESULTED IN BLOCKAGE OF AIR FLOW TO THE ENGINE AND LOSS OF ENGINE POWER. CONTRIBUTING TO THE ACCIDENT WAS THE FAILURE OF THE PILOT-IN-COMMAND TO MAINTAIN AIRSPEED AND FLARE PROPERLY DURING A FORCED LANDING.