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Universal Atomic 4 marine engine

Universal Atomic 4

1949–198430 HP4-cylindergasoline
Gasolineraw water cooledinboard
Manufacturer PageDocumentation

Legendary gasoline auxiliary engine. Powered thousands of sailboats 24-36ft from the 1950s-80s. Simple, inexpensive, smooth-running. The most common gasoline engine in sailing history. Standard output 18HP at 2500 RPM, high-output 30HP at 3500 RPM.

Specifications

Power30 HP @ 3,500 RPMCylinders4
Displacement1065.2 cc (65.0 ci)Bore x Stroke63.5 x 79.2 mm
Fuel TypeGasolineAspirationNaturally Aspirated
CoolingRaw waterDriveInboard
Weight141 kg (310 lb)Dimensions (LxWxH)679 x 464 x 333 mm
Fuel Use5.62 L/hrTransmissionOversize ball bearing reverse gear, helical reduction

Parts for the Universal Atomic 4

6 catalogued parts. Prices are reference figures; each “Find on Amazon” link opens a search for that part — confirm fitment against your engine's serial before ordering.

Cooling System (2)
  • Raw water pump impeller kit, Oberdorfer (with gasket) — Atomic 4
    fits: Jabsco 17120 / 6303-0001; Moyer CSOB_02_63
    SearchAmazon →
  • Thermostat, 140F (Holley, 1967+) — Atomic 4
    fits: Universal 275965 (Dole, earlier)
    SearchAmazon →
Fuel System (1)
  • In-line fuel filter kit — Atomic 4
    fits: FPMP_06_51
    SearchAmazon →
Lubrication (1)
  • Spin-on oil filter / oil change kit — Atomic 4
    fits: KTAS_05_90
    SearchAmazon →
Belts (1)
  • Alternator / fan belt for the Universal Atomic 4, 3/8" wide x 25" outside circumference. Gates 7250 (Continental Elite / XL Corrugated V-belt) is the size specified for the Atomic 4 alternator drive belt.
    fits: Gates 3VX250 / HC-3VX-250; NAPA 25-06353; Dayco/Goodyear 10AV0635; Drive King 3L250; Moyer Marine alternator belt
    SearchAmazon →
Anodes (1)
  • Sacrificial zinc anode (pencil), heat exchanger — Atomic 4
    fits: CFWC_04_268
    SearchAmazon →

Part data aggregated from marine-diesel parts catalogues. As an Amazon Associate, SailPages earns from qualifying purchases.

Sailboats with Universal Atomic 4(45)

ALBERG 30
ALBERG 30
Whitby Boat Works Ltd. (CAN) · 30.25ft · 1962–1987
ALBERG 35
ALBERG 35
Pearson Yachts (USA) · 34.75ft · 1961–1967
BRISTOL 29
BRISTOL 29
Bristol Yachts Inc. (USA) · 29ft · 1966–1971
BRISTOL 29.9
BRISTOL 29.9
Bristol Yachts, Inc. (USA) · 29.92ft · 1977–1986
C&C 30-1 (1-506)
C&C 30-1 (1-506)
C&C Yachts (CAN) · 30ft · 1973–1985
C&C 35-1(REDWING 35)
C&C 35-1(REDWING 35)
Hinterhoeller Ltd. / C&C · 34.58ft · 1969–1973
CAL 28
CAL 28
Jensen Marine (USA) · 28ft · 1963–1969
CAL 29
CAL 29
Jensen Marine (USA) · 29ft · 1968–1974
CAL 34
CAL 34
Jensen Marine (USA) · 33.24ft · 1968–1975
CATALINA 27
CATALINA 27
Catalina Yachts (USA) · 26.83ft · 1971–1991
CATALINA 30
CATALINA 30
Catalina Yachts (USA) · 29.92ft · 1976–2008
CATALINA 38
Catalina Yachts (USA) · 38.08ft · 1978–1990
COLUMBIA 28
COLUMBIA 28
Columbia Yachts (USA) · 27.58ft · 1967
COLUMBIA 36
COLUMBIA 36
Columbia Yachts (USA) · 35.75ft · 1967–1972
COMMANDER 26 (PEARSON)
COMMANDER 26 (PEARSON)
Pearson Yachts (USA) · 26ft · 1964–1967
CORONADO 30
Coronado Yachts (USA) · 29.92ft · 1969–1974
ERICSON 27
ERICSON 27
Ericson Yachts (USA) · 26.75ft · 1971–1978
ERICSON 29
ERICSON 29
Ericson Yachts (USA) · 28.58ft · 1970–1978
HR-28 (HINTERHOELLER)
HR-28 (HINTERHOELLER)
Hinterhoeller Yachts Ltd. (CAN) · 28.25ft · 1967
ISLANDER 28
ISLANDER 28
Islander Yachts (USA) · 27.92ft · 1975–1985
ISLANDER 29
ISLANDER 29
Wayfarer Yacht Corp. / Islander Yachts (USA) · 29.08ft · 1968–1969
ISLANDER 32
ISLANDER 32
Wayfarer Yacht Corp. (USA) · 32.5ft · 1963–1967
ISLANDER 36
ISLANDER 36
Islander Yachts (USA) · 36.08ft · 1971–1986
KAISER 26
John Kaiser (USA) · 25.83ft · 1968
MORGAN 24/25
MORGAN 24/25
Morgan Yachts (USA) · 24.92ft · 1965–1976
MORGAN 27
MORGAN 27
Morgan Yachts (USA) · 27.5ft · 1971–1976
MORGAN 28
Morgan Yachts (USA) · 27.83ft · 1969–1971
MORGAN OUT ISLAND 33
MORGAN OUT ISLAND 33
Morgan Yachts (USA) · 33ft · 1973
NEWELL CADET
NEWELL CADET
Cheoy Lee Shipyard Ltd.(HK) · 26.42ft · 1965
NEWPORT 27-1
NEWPORT 27-1
Capital Yachts Inc. (USA) · 27ft · 1970
NEWPORT 27-3
Capital Yachts Inc. (USA) · 27.16ft · 1975
NORTHERN 29
Northern Yachts Ltd. (CAN) · 29ft · 1972
ONTARIO 28
ONTARIO 28
Ontario Yachts (CAN) · 28.58ft · 1978–1985
PEARSON 10M
PEARSON 10M
Pearson Yachts (USA) · 33.04ft · 1973–1981
PEARSON 30
PEARSON 30
Pearson Yachts (USA) · 29.79ft · 1971–1981
PRIVATEER 26
PRIVATEER 26
Kenner Boat Company · 31.75ft · 1966–1974
PRIVATEER 26 KTCH
Kenner Boat Company · 31.75ft · 1966
RANGER 28
RANGER 28
Bangor Punta(USA) · 28ft · 1976–1978
RANGER 29 (MULL)
Ranger Yachts (USA) · 28.58ft · 1970–1975
S2 9.2 A
S2 9.2 A
S2 Yachts · 29.92ft · 1977–1987
TARTAN 27
TARTAN 27
Tartan Marine (USA) · 27ft · 1961–1980
TARTAN 27-2
TARTAN 27-2
Tartan Marine (USA) · 27ft · 1976–1979
TARTAN 30
TARTAN 30
Tartan Marine (USA) · 29.92ft · 1970–1978
TARTAN 3000
TARTAN 3000
Tartan Marine (USA) · 29.96ft · 1981–1988
YANKEE 30 MKI
YANKEE 30 MKI
Yankee Yachts Inc. (USA) · 30.04ft · 1970–1975