C&C 27 Mk III
Built 1974–1981 by C&C Yachts
About the C&C 27 Mk III
Researched from public sources for this model. Any individual boat may have been modified or repowered — confirm before relying on any figure.
- Built
- 1974–1981
- Builder
- C&C Yachts
- Designer
- Robert Ball
- Length
- 27.86 ft
- Waterline
- 22.86 ft
- Beam
- 9.16 ft
- Draft
- 4.5 ft
- Displacement
- 5,500 lb
- Ballast
- 2,116 lb
- Hull
- fiberglass
- Hull / keel
- fin keel
- Rig
- sloop
- Propulsion
- inboard
- Fuel
- 20 gal
- Water
- 24 gal
- Stern thruster
- not fitted
- Steering
- tiller
Tank capacities — where the figures come from
-
Fuel 20 gal
“20 U.S. gallons (76 L; 17 imp gal)” — search excerpt, nautipedia.itOnly copies of a spec database's figure agree, so they aren't independent. The C&C 27 Association's specification and repair pages give no tank capacities.
-
Water 24 gal
“24 U.S. gallons (91 L; 20 imp gal)” — search excerpt, nautipedia.itOnly copies of a spec database's figure give this. C&C was a Canadian builder: if the original brochure meant imperial gallons, the US figure would be about 20% higher, and that's unsettled.
-
Water heater unknown
C&C 27 Association evolution/specification page and spec databases do not mention a water heater.
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 unknown
No source mentions a thruster on the C&C 27; the owners' association history is silent.
-
Stern thruster not fitted
Nothing was found either way; our earlier figure of none appears to be an assumption.
-
Steering tiller
“the cockpit was lengthened, and the traveller was now mounted forward. This opened up the cockpit, and wheel steering be” — owners' association (1975), cc27association.comAccording to the C&C 27 Association, Mark I and II boats all had tillers, and on the Mark III (1974-81) wheel steering became a popular option from 1975 (sailboatdata says 1976), so tiller is shown as standard. The wheel hardware maker isn't stated.
Thrusters and steering are often replaced — check the units on your boat before ordering parts.
Sources disagree on Yanmar diesel model — left blank rather than guessed.
The Mark III name was applied retroactively by owners; boats were sold simply as the C&C 27. Hull numbers are given as 451/452-914 by the owners association and 435-915 by sailboatdata. The association says the Mark III came from a new mold with a longer cockpit/stern, deeper keel, less ballast and a taller rig. Wheel steering became a popular option in the mid-1970s (1975 per the association, 1976 (sailboatdata)). Diesel became available in 1978 and a single-cylinder Yanmar (SYP12 (sailboatdata)) was standard by the end of the run; many boats have been repowered. Shoal-draft keel (4.0 ft) was offered. Hull is solid glass (Practical Sailor says the 27 has no hull coring); deck is balsa-cored. External lead ballast through-bolted. The Mark IV (1981-82) and the later, unrelated Mark V (1984-87) are separate versions.
Engines fitted
-
Atomic 4 (Universal) gas — gas, single
standard
sailboatdata lists the Universal Atomic 4 gas engine as original equipment for the Mk III (1974-81, hulls 435-915).Sources: sailboatdata.com
- Atomic 4 (Universal) — gas standard
-
Yanmar SYP12 / 2GM (diesel) — diesel, single
factory option
sailboatdata: diesel power became an option in 1978 and near the end of the Mk III run the Yanmar SYP 12 became standard. Wikipedia's C&C 27 article names a Yanmar 2GM diesel and also dates the diesel option to 1978.Sources: sailboatdata.com · en.wikipedia.org
Boats of the same model can differ — check which engines yours actually has before ordering parts.
Generator
No source mentions a generator for the C&C 27 Mk III.
Manuals and brochures online
- Spec sheet C&C 27 Association - Evolution of the C&C 27, Marks I-IV (general specifications by mark and hull number) (1970-1982) — cc27association.com
Hosted by the builder or an owners' association; they own the copyright.
Known problems for this model
-
Wet balsa deck core around hardware deck
The deck is balsa-cored and old bedding on fittings often fails, letting water into the core; rebedding hardware and checking for delamination is a priority.practical-sailor.com
-
Bulkhead rot at chainplates interior
Water tracking down the chainplates through the deck can rot the plywood bulkheads they bolt to; inspect where the plates attach.practical-sailor.com
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Cracking at stanchion and pulpit bases deck
Sidedeck laminate is thin at the outboard edges and pulpits lacked backing plates, so look for cracks around stanchion and pulpit bases.practical-sailor.com
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Mast compression support rot hull
Practical Sailor advises checking the interior structure that carries mast compression for rot, along with the deck core.practical-sailor.com
-
Bulkheads not tabbed to deck hull
On many C&Cs of this era the bulkheads are not tabbed to the deck, which can let the deck lift as the rig works; relevant if planning offshore use.practical-sailor.com
1 more
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Keel shape makes blocking tricky other
The swept keel has no flat bottom run, so the boat tends to rock forward on jack stands and needs careful blocking when hauled.practical-sailor.com
Engines & parts
Universal Atomic 4 parts: good
Factory standard engine — you entered “Atomic 4 (Universal) gas”
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)
-
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.
Yanmar 2GM / 2GM20F parts: good
Factory optional engine — you entered “Yanmar SYP12 / 2GM (diesel)”
Well supported by Yanmar dealers and aftermarket; stainless mixing elbows that replace the OEM part numbers are widely sold.
Parts sources: Mack Boring & Parts (Yanmar distributor), HDI Marine (stainless exhaust elbows), Parts4Engines
Common problems (2)
-
Nearly blocked mixing elbow exhaust
Owners find the exhaust port of the mixing elbow almost completely blocked while the engine still runs; a failed U-elbow has also let water into a cylinder and cracked a piston.sailnet.com · practical-sailor.com
-
Noise and vibration from soft mounts engine
Worn soft engine mounts are a common cause of the vibration owners complain about; better aftermarket mounts are available.practical-sailor.com
Maker’s service schedule (2)
| Fuel filters & water separator | 250 hrs | “The normal replacement interval for the element is 250 hours ... Filter cleaning First time 50 hours Filter element repl” — manufacturer, c320.org |
| Air filter / intake silencer | 250 hrs | “Washing period Every 250 hours” — manufacturer, c320.org |
Service part numbers (10)
| Oil filter | Yanmar 119305-35170 Replaces 119305-35151, 119660-35150 |
“2GM20F Basic Service Kit ... 119305-35170 FILTER ASSY, D68XL65” — dealer, oldportmarine.com · “Suitable for: ... Yanmar 2GM, Yanmar 2GMF, Yanmar 2GM20, Yanmar 2GM20-YEU, Yanmar 2GM20F” — dealer, marinepartsystem.com |
| Fuel filter | Yanmar 104500-55710 | “Fuel Filter Element 1 104500-55710 / Fuel Filter O-Ring 1 24341-000440” — dealer, ellebogen.com · “2GM20F Basic Service Kit ... 104500-55710 ELEMENT, FUEL FILTER” — dealer, oldportmarine.com |
| Raw-water impeller Japan-built 2GM / 2GM20(F) (serial not starting with E) |
Yanmar 124223-42092 | “Impeller 1 124223-42092 / Impeller Gasket 1 124223-42110” — dealer, ellebogen.com · “2GM20F Basic Service Kit ... 124223-42092 IMPELLER, PUMP” — dealer, oldportmarine.com |
| Raw-water impeller European-built GM-YEU (serial starting with E) |
Yanmar 128990-42570 Replaces 128990-42200 |
“Impeller & O-ring Kit-128990-42570 For the GM series engines with serial numbers beginning with an E” — dealer, oldportmarine.com · “(Supersedes part number: 128990-42200) ... GM-YEU series engines:(Serial number begins with an E)2GM20-YEU” — dealer, palmerpower.com |
| Drive belt | Yanmar 25132-003700 | “Alternator Belt 1 25132-003700” — dealer, ellebogen.com · “2GM20F Basic Service Kit ... 25132-003700 V-BELT, A37” — dealer, oldportmarine.com |
| Drive belt | Yanmar 104511-78780 | “S/W Pump Belt 1 104511-78780” — dealer, ellebogen.com · “2GM20F Basic Service Kit ... 104511-78780 V-BELT, M/19” — dealer, oldportmarine.com |
| Air filter | Yanmar 128270-12540 | “Air Filter Element 1 128270-12540” — dealer, ellebogen.com · “2GM20F Basic Service Kit ... 128270-12540 ELEMENT, AIR CLEANER” — dealer, oldportmarine.com |
| Zinc / anode raw-water 2GM / 2GM20; also sold for the F (heat-exchanger) versions |
Yanmar 27210-200300 | “27210-200300 Yanmar Engine Zinc Anode For 2GM(D), 3GM(D), 2GM20, 3GM30” — dealer, zincsforboats.com · “It fits Yanmar 2GM, 2GM20F, 2GM15, 2GM20, 3GM30F, 3GMF, 3HMF, 3GM30H engines.” — dealer, deltadieselparts.com |
| Thermostat 2GM20F / 2GMF (fresh-water cooled) |
Yanmar 121750-49800 | “Thermostat 1 121750-49800 / Thermostat Gasket 1 129350-49541” — dealer, ellebogen.com · “Thermostat for Yanmar 2GMF, 3GMF, 3HMF, 2GM20F, 3GM30F, 3HM35F / REC121750-49800” — dealer, marineparts.eu |
| Thermostat 2GM / 2GM20 (raw-water cooled) |
Yanmar 105582-49200 | “Replaces Yanmar Marine 105582-49200 ... 1GM, 2GM, 3GM, 1GM10, 2GM20, 3GM30” — dealer, repowermarine.com · “1GM10, 2GM20 & 3GM30 Thermostat to fit raw water cooled engine versions ... equivalent to 105582-49200” — dealer, parts4engines.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.
Model sources (5)
sailboatdata.com · practical-sailor.com · practical-sailor.com · cc27association.com · en.wikipedia.org
Own a C&C 27 Mk III? Add her to your boats, then share a photo — names, numbers and faces are blurred before it appears.
Other C&C models
- C&C 30 Mk I 1973–1985
- C&C 33 Mk II 1984–1988
- C&C 34 1977–?
- C&C 35 Mk III ?–1987
Researched from public sources. Spotted an error? The sources are listed above — tell us what they got wrong.