AT 0555 EDT, THE NON-INSTRUMENT RATED PLT OBTAINED A WX BRIEFING FOR A FLT FROM LIMINGTON, ME TO PAWLING, NY. AT THAT TIME, HE STATED HE WAS UNSURE WHEN HE WOULD DEPART, THE DECISION DEPENDED ON THE WX. THE BRIEFER ADVISED THAT AT THAT TIME, VFR FLT WAS NOT RECOMMENDED & THAT THE PLT SHOULD OBTAIN ANOTHER BRIEFING BEFORE DEPARTING, AT APRX O900 EDT, HE TOOK OFF, AN EN ROUTE REFUELING STOP WAS MADE AT CONCORD, NH. HIS ROUTE OF FLT WAS TO THE SOUTHWEST ALONG VICTOR 93. WHEN THE ACFT WAS DETERMINED TO BE OVERDUE, A SEARCH WAS INITIATED. LATER, IT WAS FOUND WHERE IT CRASHED NEAR THE TOP OF MT MONADNOCK AT AN ELEVATION OF APRX 2900 FT ON A HEADING OF 070. AN EXAM OF THE WRECKAGE REVEALED NO EVIDENCE OF A PREIMPACT, MECHANICAL MALFUNCTION OR FAILURE. A WITNESS IN THE VICINITY SAW AN ACFT MATCHING ITS DESCRIPTION FLYING BELOW A BROKEN LAYER AT ABOUT 2000 FT MSL. HE STATED HE COULD SEE AN OVERCAST ABOVE THE BROKEN LAYER & THAT MT MONADNOCK WAS OBSCURED BY CLOUDS MOST OF THE DAY.