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Bayliner 4788 Pilothouse Motor Yacht

Built 1994–2002 by Bayliner Marine

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About the Bayliner 4788 Pilothouse Motor Yacht

Researched from public sources for this model. Any individual boat may have been modified or repowered — confirm before relying on any figure.

Illustration of a Bayliner 4788 Pilothouse Motor Yacht
Illustration, not a photo of this model. AI-generated illustration of a typical flybridge motor yacht.
Built
1994–2002
Builder
Bayliner Marine
Length
54 ft
Beam
15.08 ft
Draft
3.33 ft
Displacement
29,990 lb
Hull / keel
planing
Propulsion
inboard
Fuel
444 gal
Water
200 gal
Holding
48 gal
Water heater
engine
Generator
fitted on some boats
Bow thruster
factory option
Stern thruster
not fitted
Tank capacities — where the figures come from
  • Fuel 444 gal
    “Fuel Capacity 444 Gallons” — search excerpt (2001), yachtbuyer.com · “A 444-gallon fuel capacity” — search excerpt (1994), au.yachtworld.com · “400 gallons of fuel” — search excerpt, rabbetboats.com
    Two listings (1994, 2001) agree with 444; a buyer's-guide site rounds to 400. No builder document found.
  • Water 200 gal
    “200 gallons of fresh water” — search excerpt (1994), au.yachtworld.com · “Water ... 200 Gallons” — search excerpt (1997), westwindyachtscanada.com
    Two listings agree, but neither is a builder source.
  • Holding 48 gal
    “a 48-gallon holding tank” — search excerpt (1994), au.yachtworld.com
    One listing only.
  • Water heater engine
    “Hot water heater w/heat exchanger system” — broker listing (1997), westwindyachtscanada.com · “The 20 gallon / 1500W Kuuma water heater in our '99 4788 has begun to leak ... I suspect that this is not the original” — search excerpt (1999), baylinerownersclub.org
    The original heater size wasn't found. One 1999 boat has a 20 gal Kuuma that its owner believes is a replacement, and a 1997 listing shows a heater with an engine heat exchanger. The owner's manual couldn't be checked.

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 factory option
    “Bayliner installed a bow thruster on my 4788 and cut off the front end of the aft water tank to make room for the thrust” — owners' association, tapatalk.com · “Does anyone have experience with the install of a bowthruster on a 2000 4788.” — owners' association (2000), tapatalk.com
    Bayliner Owners' Club posts show some 4788s had a bow thruster fitted by Bayliner (under the forward berth, with the aft water tank shortened), while others were built without one and fitted later. No builder option list was found, though the factory operating manual has a bow-thruster section.
  • Stern thruster not fitted
    Our earlier figure of none has no source. Owners'-club threads discuss adding stern thrusters to these boats, but nothing was found on whether any were fitted at the factory.
  • Steering unknown
    “The fluid reservoir for the hydraulic steering system is located in the aft end of the engine compartment.” — search excerpt, shipslog.stedman.us
    Taken from a short excerpt of the Bayliner 4788 owner's manual; the full manual couldn't be checked. It uses the same pressurized-reservoir wording as the 1995 3288 manual, and no brand is named.

Thrusters and steering are often replaced — check the units on your boat before ordering parts.

LOA 54 ft includes pulpit and platform; hull length 47.3 ft. A lengthened, restyled 4588 with nearly the same three-stateroom pilothouse layout. Hinos cruise 16-18 knots, 370hp Cummins 20-22 knots.

Engines fitted

Boats of the same model can differ — check which engines yours actually has before ordering parts.

Generator

“Our Bayliner 4788 came originally equipped with a hefty Westerbeke 12.5KW diesel generator.” — broker listing (1999), technomadia.com

A Westerbeke 12.5 kW diesel in the cockpit lazarette is the usual original set (owners and listings, 1997-2001). One Owners Club post reports an 8 kW Westerbeke on a 4788, and one owner replaced the 12.5 with a Northern Lights 6 kW. No Bayliner option list or review was found.

Generators are often replaced or added — check the unit's own plate before ordering parts.

Known problems for this model

Engines & parts

Hino (US Marine) W04D / W04C-T / W06 / EH700 parts: limited

Factory standard engine — you entered “Hino W06DTA”

Sold under the US Marine name in many Bayliners. Marine Parts Supply (Canada) is the official North American distributor of Hino marine parts and imports directly from Hino Japan; North Harbor Diesel is a US source. Owners report parts are still available but some have become harder to find and pricier. W04D (about 110 hp) is considered underpowered for planing; W04C-T (135–150 hp) planes.

Parts sources: Marine Parts Supply (Hino/US Marine), Fab Heavy Parts (Hino EH700)

Common problems (2)
  • Parts availability and cost other
    The most common Hino question is whether parts are still obtainable and affordable; the distributor says most EH700 parts are stocked, while some owners report rising cost and harder-to-find items.
    marineengine.com · baylinerownersclub.org · trawlerforum.com
  • Fuel supply problems fuel
    Owners of older twin-Hino Bayliners list fuel supply issues as a top problem and recommend surveys with oil analysis.
    facebook.com
Service part numbers (12)
Oil filter
W04C-T / W04CTI / W06DTI (spin-on, oil filter base 156003490)
Mercury (US Marine) 803899T
Replaces 836071630
“19 Mercury Marine 836071630 FILTER803899T Required: 1 ... FILTER, OIL - SPIN-ON ... Replaces 836071630” — manufacturer, crowleymarine.com
Fuel filter
W04CTA (150 hp)
Mercury (US Marine) 834011133
Replaces 834011132
“5 Mercury Marine Fuel Filter834011133 Required: 1 ... FILTER, FUEL ... Replaces 834011132” — manufacturer, crowleymarine.com
Fuel filter
W06DTI (250 hp), spin-on
Mercury (US Marine) 834011341
“4 Mercury Marine Spin On Fuel Filter834011341 Required: 1 ... FILTER, FUEL - SPIN-ON” — manufacturer, crowleymarine.com
Raw-water impeller
W04CTI (210 hp) and W06DTI (250 hp) raw-water pump 831003011
Mercury (US Marine) 807184
Replaces 831311510
“NS Mercury Marine Water Pump Impeller807184 Required: 1 ... IMPELLER, PUMP ... Replaces 831311510” — manufacturer, crowleymarine.com
Raw-water impeller
W04CTA (150 hp) raw-water pump 807121T; cam and impeller kit
Mercury (US Marine) 807189A1
Replaces FI8090176
“NS Mercury Marine CAM/IMPELLER KIT807189A1 Required: 1 ... IMPELLER ... Replaces FI8090176” — manufacturer, crowleymarine.com
Raw-water impeller
EH700N / EH700TI raw-water pump 831002481
Mercury (US Marine) 809866T
Replaces 831311350
“14 Mercury Marine Water Pump Impeller809866T Required: 1 ... IMPELLER ... Replaces 831311350” — manufacturer, crowleymarine.com
Drive belt
EH700N / EH700TI raw-water pump drive (set of 2 V-belts)
Mercury (US Marine) 830149104
“33 Mercury Marine V BELT SET (2 Belts)830149104 Required: 1 ... V-BELT, RAW WATER PUMP DRIVE” — manufacturer, crowleymarine.com
Thermostat
W04CTA, W04CTI, W06DTI
Mercury (US Marine) 830146177
“12 Mercury Marine Thermostat830146177 Required: 1 ... THERMOSTAT” — manufacturer, crowleymarine.com
Thermostat
EH700N / EH700TI
Mercury (US Marine) 830146187
“53 Mercury Marine Thermostat830146187 Required: 1 ... THERMOSTAT” — manufacturer, crowleymarine.com
Air filter
W04CTI (210 hp) air cleaner 177203360
Mercury (US Marine) 838013340
Replaces 838012450
“2 Mercury Marine 178013340 ELEMENT838013340 Required: 1 ... ELEMENT ... Replaces 838012450” — manufacturer, crowleymarine.com
Air filter
W06DTI (250 hp) air cleaner 177204320
Mercury (US Marine) 838012660 × 2
“2 Mercury Marine Air cleaner element838012660 Required: 2 ... ELEMENT, AIR CLEANER” — manufacturer, crowleymarine.com
Air filter
EH700N / EH700TI air cleaner-silencer (sock element)
Mercury (US Marine) 838013290
Replaces 838012130
“5 Mercury Marine 178013290 ELEMENT838013290 Required: 1 ... SOCK, CLEANER ... Replaces 838012130” — manufacturer, crowleymarine.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.

Cummins 6BT / 6BTA 5.9 parts: good

Factory standard engine — you entered “Cummins 6BTA5.9-M3 (330 hp rating)”

Mechanically injected 5.9 L inline six from the Cummins B-series truck/industrial family, so base-engine parts are everywhere. Cummins still sells factory ReCon (remanufactured) marine 6BT/6BTA engines (152–210 hp ratings) with a 2-year/2000-hour warranty. Seaboard Marine is the best-known marine specialist, selling aftercooler/heat-exchanger service kits, upgraded raw water pumps and technical guidance; TAD also sells Cummins packages.

Parts sources: Seaboard Marine, Cummins (ReCon 6BT/6BTA), Diesel Pro Power

Common problems (2)
  • Aftercooler corrosion letting seawater into the intake cooling
    On the turbo-aftercooled 6BTA the seawater-cooled aftercooler core has vertical tubes and an aluminum housing that corrodes from condensate; a leak can put salt water into the cylinders and wreck the engine. Owners pull, clean, grease and pressure-test the core every few years and fit new O-rings.
    trawlerforum.com · sbmar.com
  • Heat exchanger and aftercooler service cooling
    Routine seawater-side service (O-rings, gaskets, zincs) is a recurring owner job; kits are sold for it and refilling coolant without trapping air is a common question.
    sbmar.com · sbmar.com
Service part numbers (5)
Oil filter Cummins 3937743
“| Oil Filter | 3937743 |” — dealer, marineenergy.com.au · “Cummins Oil Filter 3937743 Spin-on type, 3.66" outside diameter, 6.95" height” — dealer, dieselpro.com
Fuel filter
6BT 5.9 210 hp (CPL 742)
Fleetguard FF5052
Replaces FF42000, FS1251
“on-engine fuel filter with drain for all 6BT 210 B’s (CPL 742). Replaces the FF42000, FS1251.” — dealer, sbmar.com · “Cummins 6BT Fuel Filter 3931063 FF5052” — dealer, marineenergy.com.au
Fuel filter
late 6BTA (also late 4BTA and 6CTA)
Fleetguard FF5285
“Fleetguard FF5285 Fuel Filter – late 4BTA 6BTA and 6CTA’s” — dealer, sbmar.com · “Cummins 6BTA Fuel Filter 3890017 FF5285 ... suits late model Cummins 6BTA's, 6CTA8.3-M” — dealer, marineenergy.com.au
Raw-water impeller
seawater pump with 1-1/4 in hose ports (Sherwood M70/M71 type, early 4BT/6BT)
Sherwood 10615K
“Seawater Pump Impeller | **1-1/4" PORTS** 3908220 10615K” — dealer, marineenergy.com.au · “Cummins Marine Water Pump Impeller 10615K 2 9/16" diameter, 1 5/8" length” — dealer, dieselpro.com
Raw-water impeller
keyway-shaft pump, 2 in inlet / 1-3/4 in outlet, 11° offset flange (e.g. P1716/P1730 on 6BTA)
Sherwood 17000K
“**2" inlet & 1-3/4" outlet ports with 11° OFFSET flange** 17000K” — dealer, marineenergy.com.au · “Cummins Impeller for Key Shaft 17000K” — dealer, dieselpro.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 (10)

hmy.com · jamisonyachtsales.com · sysyachtsales.com · baylinerownersclub.org · baylinerownersclub.org · baylinerownersclub.org · westwindyachtscanada.com · technomadia.com · tapatalk.com · tapatalk.com

Other Bayliner models

Researched from public sources. Spotted an error? The sources are listed above — tell us what they got wrong.