O'Day 25
Built 1975–1984 by O'Day Corp.
About the O'Day 25
Researched from public sources for this model. Any individual boat may have been modified or repowered — confirm before relying on any figure.
- Built
- 1975–1984
- Builder
- O'Day Corp.
- Designer
- C. Raymond Hunt Assoc. (John Deknatel)
- Length
- 24.83 ft
- Waterline
- 21 ft
- Beam
- 8 ft
- Draft
- 6 ft
- Displacement
- 4,007 lb
- Ballast
- 1,825 lb
- Hull
- fiberglass
- Hull / keel
- centerboard
- Rig
- sloop
- Propulsion
- outboard
- Fuel
- varies by year
- Water
- 15 gal
- Number built
- 2,898
- Bow thruster
- not fitted
- Stern thruster
- not fitted
- Steering
- tiller
Tank capacities — where the figures come from
-
Fuel varies by year
“Inboard Engine - OMC Saildrive - 15 Horsepower gasoline engine ... includes: 12 gallon, aluminum fuel tank” — brochure (1981 (optional inboard)), sbo.sailboatowners.comThe standard boat is outboard-powered, with a portable tank in a cockpit locker (6 gal, according to Good Old Boat). The optional OMC Saildrive inboard on the 1980-81 option list came with a 12-gal aluminium tank, per the 1981 brochure, so there is no single standard built-in figure.
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Water 15 gal
“15 gallon seamless plastic fresh-water tank” — brochure (1981), sbo.sailboatowners.comThe 1981 O'Day Cruisers brochure lists a 15-gal seamless plastic fresh-water tank as standard on all three Cruisers (22, 23 and 25). Good Old Boat places the tank under the cockpit.
-
Holding unknown
The standard head was a portable marine head (1980 brochure). The 1981 option list offers a chemical head with built-in holding tank and deck discharge on the 23 and 25, size not given. Owners on a forum describe 20-22 gal holding tanks they added later.
-
Water heater unknown
The 1981 O'Day Cruisers builder brochure gives the O'Day 25's standard features (12 V breaker panel, plastic fresh-water tank, galley fresh-water pump) and the cruiser option list, including the OMC Saildrive 15 hp gasoline inboard. Neither has a water heater or 110 V system, though the brochure doesn't say none was available.
Tanks are often replaced or added on older boats — check the tank labels or a survey for yours.
Thrusters and steering — where this comes from
-
Bow thruster not fitted
“1981 O'Day Cruisers standard features and description of 1981 O'Day Cruiser line options (22, 23, 25): no thruster liste” — brochure (1981), sbo.sailboatowners.comThe 1981 builder brochure's full standard-feature and option lists for the Cruiser line have no thruster (1981 only).
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Stern thruster not fitted
“1981 O'Day Cruisers standard features and description of 1981 O'Day Cruiser line options (22, 23, 25): no thruster liste” — brochure (1981), sbo.sailboatowners.com
-
Steering tiller
“Transom mounted fiberglass rudder with varnished ash tiller. (1981 O'Day Cruisers standard features)” — brochure (1981), sbo.sailboatowners.com · “Tiller Extension - Adjustable length, self-locking aluminum tiller extension. (option)” — brochure (1981), sbo.sailboatowners.comBuilder brochure (Bangor Punta, 1981) lists a transom-hung fiberglass rudder with ash tiller as standard for the O'Day 22, 23 and 25; no wheel option is offered.
Thrusters and steering are often replaced — check the units on your boat before ordering parts.
Trailerable keel/centerboard masthead sloop, 2.25 ft board up and 6.0 ft down. Most were keel/centerboard, but a 4.5 ft fixed-keel version was offered (3,962 lb displacement, 1,775 lb ballast, taller rig). Usually outboard-powered (sailboatdata lists up to 15 hp); a Yanmar inboard diesel was optional. Hull and liner pan are solid hand-laid glass; shoebox hull-deck joint is screwed and bonded with 5200. Replaced by the O'Day 26 in 1984. Sailboatdata also names Bangor Punta as builder (then O'Day's parent).
Engines fitted
-
OMC Saildrive (inboard) — gas, single
factory option
The 1980 brochure's options list includes 'Inboard engine - OMC Saildrive' for the 25.Sources: static1.squarespace.com
-
Atomic 4 (Universal) Atomic 2 — 7 hp, gas, single
factory option
Henkel's review (quoted by Wikipedia): at one point the choice was an outboard or a small 7 hp Atomic 2 gas inboard, and later diesels were offered (make not given).Sources: en.wikipedia.org
- Yanmar — diesel factory option
Boats of the same model can differ — check which engines yours actually has before ordering parts.
Generator
No generator in the 1981 builder standard-feature or option lists; the O'Day 25 operating and rigging instructions cover rigging only.
Manuals and brochures online
- Brochure 1981 'The O'Day Cruisers' brochure (O'Day 22, 23, 25 - standard features and options) (1981) — sbo.sailboatowners.com
- Owner's manual O'Day 25 Operating and Rigging Instructions (Bangor Punta; no tank figures) — sbo.sailboatowners.com
Hosted by the builder or an owners' association; they own the copyright.
Known problems for this model
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Wet balsa core at added fittings deck
The deck is balsa-cored, though factory fitting areas are solid or plywood-cored. Hardware added later without sealing the core can rot large areas, so sound the whole deck, especially around fittings and chainplates.goodoldboat.com
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Chainplate leaks and main bulkhead rot rigging
The chainplates bolt to the plywood main bulkhead, which also supports the deck-stepped mast and is not tabbed to the deck. Leaks are likely here, and bulkhead rot has been found at the chainplates.goodoldboat.com
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Rudder delamination steering
The profiled owner had repeated rudder delamination. The rudder draws more than the keel with the board up and is too heavy to remove while under way.goodoldboat.com
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Centerboard pendant and pin wear hull
Centerboard pendants and pivot pins wear and break with age; inspect them. The lead ballast is sealed inside the keel molding, so there are no keel bolts.goodoldboat.com
Engines & parts
Universal Atomic 4 parts: good
Factory optional engine — you entered “Atomic 4 (Universal) Atomic 2”
Tens of thousands were built (sources say from 40,000 to 50,000). Despite being out of production for decades, the engine is well supported: Moyer Marine sells parts, rebuilt engines, fuel pump rebuilds and exhaust parts, and hosts an owners' forum; Old Lyme Marina and others also supply parts, and electronic ignition upgrades are available.
Parts sources: Moyer Marine
Common problems (3)
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Raw-water cooling scale and corrosion cooling
Most Atomic 4s are raw-water cooled, so the block scales up and corrodes, especially in salt water; cranking without starting can also flood the engine with seawater through the exhaust.goodoldboat.com · moyermarineforum.com · keelindex.com
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Gasoline vapor fire/explosion risk fuel
Gasoline vapor is heavier than air and settles in the bilge, so ventilation, blower use and shutting the fuel valve (a stuck carburetor float can overflow) matter.goodoldboat.com
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Ignition and fuel system faults electrical
Points, condenser, cap and wires, plus gummed carburetors and contaminated fuel, are the most common reasons an Atomic 4 won't run well.keelindex.com · goodoldboat.com
Maker’s service schedule (9)
| Engine oil & filter change | 50 hrs | “3. FIFTY HOUR CHECK a. Using sump pump, remove all oil from crankcase. Refill with a good grade oil as specified in Tabl” — manufacturer, westerbeke.com |
| Fuel filters & water separator | 50 hrs | “e. Clean fuel pump strainer.” — manufacturer, westerbeke.com |
| Heat exchanger & oil cooler cleaning | 50 hrs | “b. Inspect oil cooler and remove any accumulation of grit or dirt.” — manufacturer, westerbeke.com |
| Clean flame arrestor | 100 hrs | “b. Inspect flame arrestor to be sure air passages are clean and free from oil. If dirty remove and wash with kerosene.” — manufacturer, westerbeke.com |
| Check clutch (reverse gear) adjustment | 100 hrs | “4. ONE HUNDRED HOUR CHECK ... c. Check adjustment of clutch.” — manufacturer, westerbeke.com |
| Valve clearance check / adjust | 150 hrs or 1 yr | “5. ONE HUNDRED FIFTY HOUR CHECK a. Check valve tappet adjustment.” — manufacturer, westerbeke.com |
| Spark plugs inspect / replace | 150 hrs | “b. Remove, clean, and reset spark plugs.” — manufacturer, westerbeke.com |
| Transmission fluid change Universal V-drive unit (V-drive installations only; the standard reverse gear shares engine oil) | 500 hrs | “(2) After the first 50 hours of operation, drain unit and refill ... (3) Change lubricant every 500 hours of operation.” — manufacturer, westerbeke.com |
| Complete overhaul | 3,000 hrs | “At the end of three thousand hours of operation the engine should be completely overhauled.” — manufacturer, westerbeke.com |
Service part numbers (8)
| Oil filter optional add-on oil filter (not standard equipment) |
Universal 276236 | “2 Element or Cartridge 1 276236 (Oil Group, Oil Filter, Not Standard Equipment)” — manufacturer, westerbeke.com |
| Raw-water impeller Oberdorfer N202M-03 / N202M-07 replacement raw-water pump (Universal pump 295625) |
Oberdorfer 6593 | “5 Impeller 6593 6593 6593 6593 6593 1 (N202M, N202M-03, N202M-07 parts list)” — manufacturer, pumpsandpartsonline.com · “Impeller : Catalog # 6593, Impeller” — dealer, pumpagents.com |
| Raw-water pump kit Oberdorfer N202M-03 / N202M-07 raw-water pump |
Oberdorfer 10725 | “REPAIR KIT N202M N202M-03 N202M-07 10725” — manufacturer, pumpsandpartsonline.com · “Catalog # 10725, Repair Kit, includes O-Ring, Snap Ring, Impeller, 2 x Lip Seal” — dealer, pumpagents.com |
| Drive belt alternator belt (Prestolite and Motorola alternators) |
Universal 239387 | “19 Belt 1 239387 (12 Volt - Motorola 51 Amp Alternator)” — manufacturer, westerbeke.com |
| Spark plug | Universal 273276 × 4 | “8 Spark plugs, champion 4 273276” — manufacturer, westerbeke.com |
| Thermostat late style, from 1967 / serial #79476 (Holley 145 F, on cylinder head) |
Universal 200206 | “12 Thermostat Kit 1 200206 consists of 262278 and 261601” — manufacturer, westerbeke.com |
| Thermostat Dole type, before serial #79476 (on manifold) |
Universal 200207 | “13 Kit, Thermostat (consists of 275965 & 261144) 1 200207” — manufacturer, westerbeke.com |
| Zinc / anode fresh-water-cooled engines only (Universal heat-exchanger kit) |
Universal 299760 | “23 zinc pencil 1 299760 (Cooling, Fresh Water System, after serial #79476)” — manufacturer, westerbeke.com |
From the engine maker’s parts lists, or two independent parts dealers. Numbers change with serial number and get superseded — check yours before ordering.
Sources disagree on first year, last year, number built — left blank rather than guessed.
Model sources (5)
sailboatdata.com · goodoldboat.com · static1.squarespace.com · en.wikipedia.org · sbo.sailboatowners.com
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Researched from public sources. Spotted an error? The sources are listed above — tell us what they got wrong.