Engines · piston (reciprocating) · data as of October 5, 2026

Jacobs L4 /R755-7

225 aircraft on the U.S. register carry a Jacobs L4 /R755-7 engine, rated at about 245 horsepower. The Cessna 195 is the model most often fitted with it (91 aircraft). The aircraft carrying it were built between 1929 and 1965.

The FAA records engines by code, usually at the level of a series ("O-320 series") rather than the exact variant; this page gathers every FAA code that reads as Jacobs L4 /R755-7. FAA spelling: L4 /R755-7.

Fitted to model families

Cessna 19591Cessna T-5027Waco YKS-718Waco YKS-613Beechcraft B175Waco YQC-65Beechcraft C175Beechcraft E175Waco YKC4Waco YMF4Waco YOC4Fairchild 244

Cessna 195 · Cessna T-50 · Waco YKS-7 · Waco YKS-6 · Beechcraft B17 · Waco YQC-6 · Beechcraft C17 · Beechcraft E17 · Waco YKC · Waco YMF

Where they are owner's state

Texas22California19Ohio16Washington14Illinois10Tennessee9Pennsylvania9Florida8Delaware8Virginia7

Kind of aircraft

Piston singles195 (87%)Piston twins30 (13%)

When the aircraft were built by decade

What the FAA has certified, ordered and been told about the Jacobs L4 /R755-7 the component layer

No FAA order in the current files names this engine series. Operators and repair shops have filed 16 failure reports with the FAA since 1995, 16 of them in the last ten years.

Failure reports 16 since · what operators and shops told the FAA

Parts most often reported as the reports name them

Hinge Bracket12Bracket2Brake Assy1Spar1

Latest reports

2006-01-04Brake Assy: corroded

2004-05-25Hinge Bracket: cracked

2004-05-25Hinge Bracket: corroded

Sources: the FAA's type certificate data sheets, airworthiness directives, supplemental type certificates, special conditions and special airworthiness information bulletins (Dynamic Regulatory System), and the FAA's service difficulty reports. A failure report is what an operator or repair station chose to file; the counts show reporting as much as reliability, and larger and commercial fleets report more. How the systems are grouped.

Connections how this engine series links to the rest of the register

Fitted to

Cessna 195 91 with this engine series
Cessna T-50 27 with this engine series
Waco YKS-7 18 with this engine series
Waco YKS-6 13 with this engine series
Beechcraft B17 5 with this engine series
Waco YQC-6 5 with this engine series
Beechcraft C17 5 with this engine series
Beechcraft E17 5 with this engine series

Where they are

Texas 22 of these aircraft
California 19 of these aircraft
Ohio 16 of these aircraft
Washington 14 of these aircraft
Illinois 10 of these aircraft

Biggest operators

Beechcraft Heritage Museum INC 4 of these aircraft
Port Townsend Aero Museum 3 of these aircraft
Mid Atlantic Air Museum 3 of these aircraft
Western Antique Aeroplane & Automobile Museum 2 of these aircraft

Airworthiness

Failure reports on the Jacobs L4 /R755-7 16 reports since 1995

Analytics

These connections as data: /graph/engine/jacobs-l4-r755-7.json · about the eFlight graph.

Aircraft newest certificates first · 225

Tail no.	Maker and model	Group	Owner and base	Certificate	Registered	Status
N14607	Waco YMF	Fixed-wing, single engine	Individual owner Ohio	Standard	1992-02-12	Valid
N962W	Beech C17L	Fixed-wing, single engine	Beechcraft Heritage Museum INC Tullahoma, Tennessee	Standard	1991-11-16	Valid
N9828A	Cessna 195A	Fixed-wing, single engine	Individual owner Washington	Standard	1991-05-17	Valid
N59V	Stinson SR-8D	Fixed-wing, single engine	Individual owner Texas	Standard	1991-01-28	Valid
N8114	Curtiss Wright TRAVEL AIR D-4000	Fixed-wing, single engine	Individual owner Arkansas	Restricted	1990-10-09	Valid
N4394N	Cessna 195	Fixed-wing, single engine	Individual owner Virginia	Standard	1990-07-17	Valid
N65340	Boeing A75N1(PT17)	Fixed-wing, single engine	Individual owner Texas	Standard	1988-01-14	Valid
N4476C	Cessna 195A	Fixed-wing, single engine	Individual owner Texas	Standard	1987-12-23	Valid
N578EK	Cessna T-50	Fixed-wing, multi-engine	Individual owner Texas	Standard	1987-07-24	Valid
N60131	Boeing PT-17	Fixed-wing, single engine	Individual owner Montana	Restricted	1987-03-16	Valid
N41793	Cessna T-50	Fixed-wing, multi-engine	Mid Atlantic Air Museum Reading, Pennsylvania	Standard	1986-12-08	Valid
N9800A	Cessna 195A	Fixed-wing, single engine	Co-owned owner Washington	Standard	1986-01-21	Valid
N55142	Cessna UC-78	Fixed-wing, multi-engine	Individual owner Michigan	Standard	1984-11-19	Valid
N9348A	Cessna 195B	Fixed-wing, single engine	Individual owner Connecticut	Standard	1984-09-17	Valid
N17083	Beech F17D	Fixed-wing, single engine	Beechcraft Heritage Museum INC Tullahoma, Tennessee	Standard	1982-02-12	Valid
N16588	Waco YKS-6	Fixed-wing, single engine	Individual owner California	Standard	1981-12-28	Valid
N195DF	Cessna 195	Fixed-wing, single engine	Individual owner Texas	Standard	1980-09-12	Valid
N17462	Waco YKS-7	Fixed-wing, single engine	Individual owner Oregon	Standard	1973-11-20	Valid
N9849A	Cessna 195A	Fixed-wing, single engine	Co-owned owner Illinois	Standard	1971-09-13	Valid
N16229	Waco YQC-6	Fixed-wing, single engine	Individual owner Illinois	Standard	1969-06-19	Valid
N14615	Waco YOC	Fixed-wing, single engine	Cacic Aviation INC Montello, Wisconsin	Standard	1968-10-02	Valid
N14132	Waco YMF	Fixed-wing, single engine	Individual owner Ohio	Standard	1963-07-10	Valid
N14684	Waco YOC	Fixed-wing, single engine	Individual owner South Carolina	Standard		Pending
N195DR	Cessna 195	Fixed-wing, single engine	Individual owner California	Standard		Pending
N4439C	Cessna 195	Fixed-wing, single engine	Individual owner Delaware	Standard		Pending

Source: FAA Civil Aviation Registry, Releasable Aircraft Database (the engine reference table and each aircraft's engine code), October 5, 2026. Horsepower and thrust are the FAA's figures for the series, not for a particular aircraft.