Post 50 Convertible
Built 1989–2008 by Post Marine
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About the Post 50 Convertible
Researched from public sources for this model. Any individual boat may have been modified or repowered — confirm before relying on any figure.
- Built
- 1989–2008
- Builder
- Post Marine
- Length
- 50.58 ft
- Beam
- 16.92 ft
- Draft
- 4.5 ft
- Displacement
- 57,122 lb
- Hull
- fiberglass-cored
- Hull / keel
- planing
- Propulsion
- inboard
- Fuel
- 870 gal
- Water
- 240 gal
- Holding
- 42 gal
- Generator
- fitted on some boats
- Stern thruster
- not fitted
- Steering
- hydraulic
Tank capacities — where the figures come from
-
Fuel 870 gal
No Post Marine document was found (the builder has closed). Everything agrees on 870 gal: Motor & Keel's model spec page, and listings for a 1992 boat (two tanks) and a 2003 boat.
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Water 240 gal
Motor & Keel and the 1992 and 2003 listings all say 240 gal.
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Holding 42 gal
1992 and 2003 listings both say 42 gal (one tank).
-
Water heater unknown
The Post Yachts sales brochure lists 240 gal water, 870 gal fuel and 42 gal holding, but no 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
The Post 50 builder brochure mentions no thruster; no option list found.
-
Stern thruster not fitted
Our earlier figure of none has no source, and nothing was found either way.
-
Steering hydraulic
“Standard hydraulic steering provides excellent response. But, you can also order a power assist that delivers finger tou” — brochure, static1.1.sqspcdn.comThe builder brochure (Post Yachts, Mays Landing, New Jersey) lists hydraulic steering as standard, with power assist optional. No maker is named, and the brochure year isn't printed.
Thrusters and steering are often replaced — check the units on your boat before ordering parts.
Over 100 built (hulls_built is that lower bound). Cored hullsides, solid glass bottom, low deadrise (7 deg); untapered transom gives a ~150 sq ft cockpit. Fuel tanks moved aft in 1995 improving engine-room headroom; bridge widened 1997. Build count (approximate, not stored): HMY: over 100 delivered.
Engines fitted
-
Detroit Diesel 8V92TA — 735 hp, diesel, twin
standard
HMY: among several engine options over the years, 735 hp 8V92s cruise in the high 20s.Sources: hmy.com
-
MAN — 860 hp, diesel, twin
factory option
HMY: later models with 860 hp MANs cruise about 30 kn; model not named.Sources: hmy.com
-
Caterpillar 3406 — 800 hp, diesel, twin
factory option
A 2001 boat is listed with twin Cat 3406s at 800 hp each.Sources: marinesource.com
-
Detroit Diesel Series 60 (MTU/DDC) — 825 hp, diesel, twin
factory option
Two different 2005 boats are listed with twin MTU/Detroit Series 60 engines at 825 hp each.Sources: siyachts.com · capstanyachts.com
Boats of the same model can differ — check which engines yours actually has before ordering parts.
Generator
“All machinery installations were designed for trouble-free service and easy maintenance - whether replacing a fuel filte” — brochure, static1.1.sqspcdn.com
The builder's undated brochure, from later production, shows a 15 kW generator in the engine room but doesn't say whether it was standard.
-
Generator (make not stated) — 15 kW
Post's brochure describes the engine room with a 15 kW generator but does not say standard or optional, nor the make or fuel (the boat is diesel-powered).“changing oil in the engines or 15kW generator” — brochure, static1.1.sqspcdn.com
Generators are often replaced or added — check the unit's own plate before ordering parts.
Manuals and brochures online
- Brochure Post 50 Convertible sales brochure (Post Yachts, Mays Landing NJ; specifications, layouts) — static1.1.sqspcdn.com
Hosted by the builder or an owners' association; they own the copyright.
Known problems for this model
No well-sourced problem reports found yet.
Engines & parts
Detroit Diesel 8V-92 (TA / TTA) parts: good
Factory standard engine — you entered “Detroit Diesel 8V92TA”
736 cu in two-stroke V8. Mechanical and early DDEC versions; overhaul kits and parts are plentiful through Detroit aftermarket suppliers. High-output versions are expensive to keep healthy.
Parts sources: Diesel Pro Power (Detroit Diesel parts)
Common problems (3)
-
Short life at high ratings engine
Owners report major overhauls around 2,000 hours being common on ~720 hp versions; the high-output engines are described as intolerant of anything out of adjustment, while lower-rated motor-yacht versions last longer.samsmarine.com · samsmarine.com
-
Marginal cooling capacity cooling
Keeping coolers clean and temperatures below about 185 F is stressed; overheating in warm water is a frequent complaint.samsmarine.com · facebook.com
-
Turbo housing damage exhaust
Poorly supported exhaust can crack turbo housings; turbo rebuilds for oil 'slobbering' are also mentioned.samsmarine.com
Maker’s service schedule (28)
| Engine oil & filter change | 150 hrs | “Industrial & Marine 150 Hours (max. engine oil change interval)” — manufacturer, archive.org |
| Fuel filters & water separator mechanical-governor engines (1985 Series 92 operator's manual 6SE381) | 300 hrs | “Install new elements every 300 hours or when plugging is indicated” — manufacturer, archive.org |
| Fuel filters & water separator DDEC II/III engines (1994 Series 92 operator's guide 68E506, marine chart) | 150 hrs | “150 HOUR ... Fuel/Water Separator and Filter (10) - Replace” — manufacturer, archive.org |
| Coolant replacement & freeze-point test mechanical-governor engines (1985 Series 92 operator's manual 6SE381) | 1,000 hrs | “Clean the cooling system every 1,000 hours using a good radiator cleaning compound” — manufacturer, archive.org |
| Coolant replacement & freeze-point test DDEC II/III engines (1994 Series 92 operator's guide 68E506, marine chart) | 4,000 hrs or 2 yrs | “replacing coolant ... annually. However, a cooling system properly maintained and protected with supplemental corrosion” — manufacturer, archive.org |
| Engine pencil zincs mechanical-governor engines (1985 Series 92 operator's manual 6SE381) | 500 hrs or 1 yr | “Every 500 hours or annually, drain the water from the heat exchanger raw water inlet and outlet tubes ... [remove the zi” — manufacturer, archive.org |
| Engine pencil zincs DDEC II/III engines (1994 Series 92 operator's guide 68E506, marine chart) | 1 yr | “Heat exchanger "zincs" should be checked initially every 60 hours, then as required or annually” — manufacturer, archive.org |
| Heat exchanger & oil cooler cleaning mechanical-governor engines (1985 Series 92 operator's manual 6SE381) | 1,000 hrs | “remove the retaining cover every 1,000 hours and inspect the heat exchanger core” — manufacturer, archive.org |
| Heat exchanger & oil cooler cleaning DDEC II/III engines (1994 Series 92 operator's guide 68E506, marine chart) | 4,000 hrs or 4 yrs | “Replace tube and shell type heat exchangers on marine engines every 4 years or 4,000 hours, whichever comes first” — manufacturer, archive.org |
| Drive belts inspect / replace mechanical-governor engines (1985 Series 92 operator's manual 6SE381) | 200 hrs | “check the tension of the drive belts every 200 hours” — manufacturer, archive.org |
| Drive belts inspect / replace DDEC II/III engines (1994 Series 92 operator's guide 68E506, marine chart) - pleasure craft | 1,000 hrs | “check the tension of the drive belts every 200 hours (150 hours on marine units)” — manufacturer, archive.org |
| Injector test / service DDEC II/III engines (1994 Series 92 operator's guide 68E506, marine chart) - pleasure craft | 1,000 hrs | “Replace fuel injectors on pleasure craft marine engines every 1,000 hours of operation” — manufacturer, archive.org |
| Injector test / service DDEC II/III engines (1994 Series 92 operator's guide 68E506, marine chart) - commercial marine | 5,000 hrs | “Replace injectors on commercial marine engines every 5,000 hours of operation” — manufacturer, archive.org |
| Air filter / intake silencer mechanical-governor engines (1985 Series 92 operator's manual 6SE381) - dry-type air cleaner | 1 yr | “replaced with new elements after one year of service or when the maximum allowable air intake restriction has been reach” — manufacturer, archive.org |
| Air filter / intake silencer DDEC II/III engines (1994 Series 92 operator's guide 68E506, marine chart) - marine air separators | 500 hrs or 1 yr | “Replace filter elements after one year or 500 hours of engine operation, whichever comes first” — manufacturer, archive.org |
| Transmission fluid change Allison Torqmatic marine gear (1985 manual) | 200 hrs | “Torqmatic Marine Gear (6V and 8V): ... Drain the oil every 200 hours and flush the gear with light engine oil” — manufacturer, archive.org |
| Clean crankcase breather mechanical-governor engines (1985 Series 92 operator's manual 6SE381) | 1,000 hrs | “[Remove the externally mounted crankcase] breather assembly every 1,000 hours and wash the steel mesh pad” — manufacturer, archive.org |
| Clean crankcase breather DDEC II/III engines (1994 Series 92 operator's guide 68E506, marine chart) | 5,000 hrs | “crankcase breather assembly should be removed and the steel mesh pad cleaned ... every 1,000 hours (5,000 hours on marin” — manufacturer, archive.org |
| Replace cooling system hoses DDEC II/III engines (1994 Series 92 operator's guide 68E506, marine chart) - pleasure craft | 1,000 hrs | “Replace all cooling system hoses on pleasure craft marine engines after 1,000 hours of service, regardless of apparent c” — manufacturer, archive.org |
| Replace fuel/boost coolers and marine gear oil cooler DDEC II/III engines (1994 Series 92 operator's guide 68E506, marine chart) | 4,000 hrs or 4 yrs | “Replace marine gear oil coolers every 4 years or 4,000 hours, whichever comes first” — manufacturer, archive.org |
| Inspect blower screen mechanical-governor engines (1985 Series 92 operator's manual 6SE381) | 1,000 hrs | “[Inspect the blower screen and gasket assembly] every 1,000 hours” — manufacturer, archive.org |
| Check thermostats and seals mechanical-governor engines (1985 Series 92 operator's manual 6SE381) | 5,000 hrs or 1 yr | “Check the thermostats and seals at 5,000 hours or once a year” — manufacturer, archive.org |
| Replace thermostats and seals DDEC II/III engines (1994 Series 92 operator's guide 68E506, marine chart) | 4,000 hrs | “Thermostats & Seals (31) - Replace [4,000 hours column, marine chart]” — manufacturer, archive.org |
| Inspect all hoses mechanical-governor engines (1985 Series 92 operator's manual 6SE381) | 500 hrs or 1 yr | “all hoses should be thoroughly inspected at least every 500 operating hours (1,000 hours for the fire-resistant ...) and” — manufacturer, archive.org |
| Coolant filter/conditioner element (if fitted) mechanical-governor engines (1985 Series 92 operator's manual 6SE381) | 500 hrs | “[coolant filter element should be] changed every 500 hours” — manufacturer, archive.org |
| Test air shutdown valve DDEC II/III engines (1994 Series 92 operator's guide 68E506, marine chart) | 500 hrs or 1 yr | “at least once a year or after 700 hours of engine operation (500 hours on marine units), whichever comes first” — manufacturer, archive.org |
| Check engine and marine gear mounts | 2,000 hrs | “the condition of the mounting pads every 2,000 hours” — manufacturer, archive.org |
| Replace fresh-water pump seal mechanical-governor engines (1985 Series 92 operator's manual 6SE381) | 6,000 hrs | “[Replace the water pump seal after it has been in] service for 6,000 hours” — manufacturer, archive.org |
Service part numbers (15)
| Oil filter full-flow cartridge element (shell-type filter) |
Detroit Diesel 5573014 Also: AC Delco PF132 |
“4.2250 - ELEMENT, OIL FILTER ... 5573014 ELEMENT (AC TYPE PF-132 INCL. GASKET IN 4.2300)” — manufacturer, archive.org |
| Oil filter spin-on full-flow filter (engines with spin-on adaptor) |
Detroit Diesel 25010495 Also: AC Delco PF911 |
“4.2250 - ELEMENT, OIL FILTER ... 25010495 ... ELEMENT (SPIN-ON) (TYPE PF-9 1 1) [OCR]” — manufacturer, archive.org |
| Fuel filter secondary filter, spin-on (3/4 in. thread base) |
Detroit Diesel 23530707 Replaces 25010778 Also: AC Delco TP916 |
“25010778 Superceded by DN 23530707” — dealer, powerlinecomponents.com · “Detroit Diesel Secondary Fuel Filter - 23530707 - Series 60 Series 53 Series 71 Series 92 Series 149” — dealer, industrialtecsupply.com |
| Fuel filter secondary filter, shell type (8 in. paper element) |
Detroit Diesel 5574508 Also: AC Delco TP540X |
“2.3320 ... 5574508 ... ELEMENT (8" PAPER) (TP-540X)” — manufacturer, archive.org |
| Fuel pre-filter / separator primary fuel strainer, spin-on (1 in. thread base) |
Detroit Diesel 25010776 Also: AC Delco T915 |
“25010776 CARTRIDGE. FUEL STRAINER (SPIN ON) (T-915)” — manufacturer, archive.org |
| Fuel pre-filter / separator primary fuel strainer, shell type (8 in. sock element) |
Detroit Diesel 5575032 Also: AC Delco T552 |
“2.3010 - ELEMENT, FUEL STRAINER ... 5575032 ELEMENT (8" SOCK TYPE) (AC TYPE T-552)” — manufacturer, archive.org |
| Raw-water impeller raw-water pump 5122599 / 23507972 (3 1/2 in., spline drive), normal water temperature |
Detroit Diesel 8924839 | “5.6 230 - IMPELLER, RAW WATER PUMP 6A 8924839 IMPELLER (USE IN NORMAL WATER TEMP).” — manufacturer, archive.org · “Impeller for Detroit Diesel, Scania and Volvo Penta Marine Water Pumps 8924839 Impeller with 12 Blades and 12 Spline Dri” — dealer, dieselpro.com |
| Raw-water pump kit raw-water pump 5122599 / 23507972 (spline drive) |
Detroit Diesel 5197222 | “5.6025 - RECONDITIONING KIT, RAW WATER PUMP 5197222 RECONDITIONING KIT” — manufacturer, archive.org · “Detroit Diesel Marine Water Pump repair kit for 6-71, 8V71, 8V53, 12V71, 6V92, 8V92 5197222” — dealer, dieselpro.com |
| Raw-water impeller raw-water pump 23507475 (3 1/2 in. impeller, double-flat drive, 6-screw cover) |
Detroit Diesel 8927570 | “5.6 230 - IMPELLER, RAW WATER PUMP ... 8927570 IMPELLER.” — manufacturer, archive.org · “Impeller for Caterpillar and Detroit Diesel Marine Water Pumps 8927570 Impeller with 12 Blades and Double Flat Drive” — dealer, dieselpro.com |
| Raw-water pump kit raw-water pump 23507475 (double-flat drive) |
Detroit Diesel 8927566 | “5.6025 - RECONDITIONING KIT, RAW WATER PUMP ... 8927566 RECONDITIONING KIT” — manufacturer, archive.org · “Detroit Diesel Marine Water pump Repair Kit for Series 71 & 92 8927566 For pumps with 3 1/2 " diameter impeller. 6 screw” — dealer, dieselpro.com |
| Zinc / anode electrode assembly, 2 1/8 in. (raw-water pump inlet and exchanger) |
Detroit Diesel 8517479 × 2 | “5.6575 - ELECTRODE, RAW WATER PUMP 8517479 ELECTRODE ASSY. (2 1/8" L. ELECT.) (5.5010)” — manufacturer, archive.org · “A-8517479 2 2 2 2 Electrode Assembly - 2 1/8" L At pump inlet & exchanger” — dealer, interstate-mcbee.com |
| Zinc / anode electrode assembly, 3 3/8 in. (heat exchanger) |
Detroit Diesel 8515850 × 2 | “5.5010 - ELECTRODE, HEAT EXCHANGER 8515850 ELECTRODE ASSY. (3 3/8" L ELECT.)” — manufacturer, archive.org · “A-8515850 2 2 2 2 Electrode Assembly - 3 3/8" L In exchanger” — dealer, interstate-mcbee.com |
| Thermostat 170 F, full-blocking (seal 5132155 separate) |
Detroit Diesel 23503826 × 2 | “5.2050 - THERMOSTAT ASSY. 23503826 THERMOSTAT (170 DEG OPENING TEMP.)” — manufacturer, archive.org · “Thermostat for Detroit Diesel 23503826 170 Degrees” — dealer, dieselpro.com |
| Thermostat 160 F, full-blocking (seal 5132155 separate) |
Detroit Diesel 5102112 × 2 | “5102112 THERMOSTAT (160 DEG. OPENING TEMP.)” — manufacturer, archive.org · “Detroit Diesel Thermostat for series 71 and 92 5102112 160 degrees” — dealer, dieselpro.com |
| Air filter air silencer element, 8.16 x 7 in. (engines with Detroit air silencers) |
Detroit Diesel 6422214 | “3.2002 - ELEMENT, AIR SILENCER 6422214 ELEMENT (8.1 6'X7' L.) [OCR]” — manufacturer, archive.org |
From the engine maker’s parts lists, or two independent parts dealers. Numbers change with serial number and get superseded — check yours before ordering.
Detroit Diesel Series 60 (marine) parts: good
Factory optional engine — you entered “Detroit Diesel Series 60 (MTU/DDC)”
Four-stroke electronic (DDEC I–IV) inline six in 11.1 L (1987–1998), 12.7 L (1987–2007) and 14.0 L (2001–2011) versions per a marine service guide. Shares the huge truck population, so parts are plentiful; DDEC diagnostics need proper software/tools.
Parts sources: Diesel Pro Power (Detroit Diesel parts)
Common problems (2)
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DDEC fault codes and electronics electrical
Owners wrestle with DDEC diagnostic codes; early DDEC control problems were often traced to battery/voltage issues.yachtforums.com · marinetechsvcs.com
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Smoke, power loss and overheating engine
Marine service guides list excessive smoke, power loss, overheating and internal noises as the usual Series 60 complaints; the highest-rated versions had more issues and are tall for some engine rooms.marinetechsvcs.com · samsmarine.com
Maker’s service schedule (1)
| Engine oil & filter change pleasure-craft ratings (2003 DDC brochure) | 250 hrs | “allows for up to 250 hours of boating between oil changes.” — manufacturer (2003,2003), maritimepropulsion.com |
Model sources (5)
hmy.com · marinesource.com · siyachts.com · capstanyachts.com · static1.1.sqspcdn.com
Researched from public sources. Spotted an error? The sources are listed above — tell us what they got wrong.