Jacobs L-4MB
1 aircraft on the U.S. register carry a Jacobs L-4MB engine, rated at about 245 horsepower. The Waco ASO is the model most often fitted with it (1 aircraft).
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 L-4MB. FAA spelling: L-4MB.
Fuel: 100LL avgas.
What the FAA has certified, ordered and been told about the Jacobs L-4MB the component layer
No FAA order in the current files names this engine series. Operators and repair shops have filed 1 failure report with the FAA since 1995, 1 of them in the last ten years.
Failure reports 1 since · what operators and shops told the FAA
Failure reports by year, as a table
| reports | |
|---|---|
| 95 | 1 |
Parts most often reported as the reports name them
Latest reports
Approved replacement parts 1 parts manufacturer approvals
Parts a company other than the maker may make for this engine and sell as FAA-approved. The companies holding the most:
Most often: battery timer (1).
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
- Waco ASO 1 with this engine series
- Ohio 1 of these aircraft
- Failure reports on the Jacobs L-4MB 1 reports since 1995
The whole map of how records connect · these connections as data: /graph/engine/jacobs-l-4mb.json.
Aircraft newest certificates first · 1
Source: FAA Civil Aviation Registry, Releasable Aircraft Database (the engine reference table and each aircraft's engine code), November 2, 2026. Horsepower and thrust are the FAA's figures for the series, not for a particular aircraft.