Custom Boat Manual

Models › Bayliner

Bayliner 4550 / 4588 Pilothouse Motor Yacht

Built 1984–1993 by Bayliner Marine

Own one? Keep her maintenance, manuals and checklists here — free Shopping? Find the right used boat

About the Bayliner 4550 / 4588 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 4550 / 4588 Pilothouse Motor Yacht
Illustration, not a photo of this model. AI-generated illustration of a typical flybridge motor yacht.
Built
1984–1993
Builder
Bayliner Marine
Length
45.33 ft
Beam
14.92 ft
Draft
3 ft
Displacement
28,000 lb
Hull
fiberglass-cored
Hull / keel
planing
Propulsion
inboard
Fuel
444 gal
Water
200 gal
Holding
48 gal
Stern thruster
none
Steering
hydraulic · Hynautic

Called 4550 Pilothouse 1984-88. Low-deadrise (6 deg) fully cored hull with a shallow keel; cruises 16-17 knots near 1 nmpg with the Hinos. Three staterooms, raised pilothouse, transom door, flybridge davit. Succeeded by the lengthened 4788. Build count (approximate, not stored): HMY: over 350 built.

Known problems for this model

Steering

Hynautic — K-series pressurized hydraulic steering (H-series helms, K-series cylinders) parts: obsolete

SeaStar bought Hynautic and kept making components and rebuild kits for years; after Dometic bought SeaStar, Hynautic pages and parts were removed from Dometic's site. Helms H-21 through H-52 and cylinders K-6 through K-31 are discontinued. Seatech Marine Products publishes SeaStar direct-replacement equivalents (e.g., H-50/H-52 replacement kits usable in the pressurized system with a non-vented fill plug) and offers rebuild services; independent hydraulic shops rebuild helms and cylinders for roughly $250–350 each. Kobelt/Accu-Steer also supply steering and power-assist equipment used on larger boats.

Parts sources: Seatech Marine Products (Hynautic alternatives & rebuilds), Kobelt (marine steering systems)

Common problems (3)
  • Helm pump shaft seal leaks steering
    The upper helm shaft seal deteriorates from sun, salt and dirt and weeps oil; raising system pressure is only a stopgap, and the helm must be removed and resealed.
    samsmarine.com · trawlerforum.com · youtube.com
  • Cylinder rod seal leaks steering
    Damaged wiper/rod seals let fluid out the end of K-6 type cylinders.
    facebook.com
  • Olive-type tubing fittings leak steering
    Some owners dislike Hynautic's olive compression fittings on plastic tubing because they are prone to leaks.
    trawlerforum.com
Model sources (3)

hmy.com · baylinerownersclub.org · baylinerownersclub.org

Other Bayliner models

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