Event Summary
Shortly after lifting off, the pilot heard a pronounced decrease in engine noise and observed that the tachometer indication had dropped to 1950 RPM. The pilot elected to abort the takeoff but was unable to stop the aircraft on the remaining runway. After departing the runway, the aircraft struck an object and ran into a ravine before coming to rest.
Findings
Examination of the Marvel Shebler carburetor, model MA4SPA, revealed a leak in the gasket with part number 16-A48. Evidence indicated that this leak would result in partial fuel starvation, consistent with the reported loss of engine power.