Baystar Hydraulic Steering Cylinder HC4645H-3 Outboard up to 150hp

$745.00 inc GST

or 4 payments of $186.25 with Wizit learn more

Baystar Compact Front Mount Outboard Cylinder Part No. HC4645H

Cylinder only.

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UPC: 731957932013

Condition:  New

In stock



Baystar Compact Front Mount Hydraulic Steering Cylinder Outboard – Part No. HC4645H-3 Up to 150HP

Cylinder Capacities – SeaStar Solutions Part No. HC4645H (dash 3 – third generation)

Cylinder Model: Front Mount

Bore: 1.25″ / 31.7mm

Shaft Dia.: .625″ / 15.9mm

Stroke: 8″ / 203mm

Volume: 118.6cc / 7.2 cu in

Torque: N/A


Baystar hydraulic steering is brought to you by the manufacturers of SeaStar®, the most trusted name in pleasure boat steering. BayStar allows you to install all of the safety, reliability and comfort of hydraulic steering onto your boats rated up to MAX. 150HP as rated by the engine manufacturer. Combine this with the superior SeaStar Solutions design team, rigid ISO quality control and teamed with the finest materials and precision manufacturing BayStar continues the tradition of bringing comfort and safety to boating.

BayStar is NOT recommended in applications with high steering effort (i.e. such as those using high-performance engines or boats capable of attaining high speeds), customers should consider upgrading the system to SeaStar/SeaStar Pro steering. This will reduce the steering effort due to the fact that SeaStar steering provides more output power resulting in lower steering effort.

Features – Baystar Hydraulic Steering HC4645H

  • Patented No FeedBack steering lock valves.
  • 5.2 turns lock-to-lock.
  • Up to 150 horsepower (total).
  • Available either as separate components or as a complete system ready to install.
  • Fixed cylinder.
  • Requires 3″ (76mm) cut-out hole in dash (Helm)
  • Requires 21″ (534mm) splashwell width.

DO NOT use BayStar on smaller HP outboard engines that use wing nut-type transom mount clamping screws.

Tilt Helm HH4315 is available separately. Currently not available in kit form.


APPLICATION GUIDE – Baystar Steering Cylinder

(Cylinders HC4645H/47H/48H/58H)

FORCE 1985 to DATE 90-150 HP HC4645H
HONDA 1992-DATE 30-90 HP HC4645H
1998 – 2009 115-130 HP HC4647H
2001-DATE 150 HP HC4645H
2003-DATE BF135 HP HC4645H
2010-DATE 115-150 HP HC4645H
JOHNSON / EVINRUDE 1977 – 1990 65-150 HP HC4648H
1991 to DATE 40-150 HP HC4645H
1997-DATE 115 HP FICHT HC4658H See Notes 4, 5
1997-DATE 75-150 HP FICHT HC4645H
1998-DATE 40-140 HP 4-Stroke HC4658H See Notes 1, 4
MERCURY/MARINER 1984 to DATE 75-150 HP HC4645H
NISSAN 1990 to DATE 120-140 HP HC4645H
SUZUKI 1986 to DATE 150 HP HC4645H
1996 ONLY 115-140 HP N/A
1987 – 2002 115-140 HP HC4645H See Note 1
1990 – 2000 90-100 HP HC4645H
1998-DATE 40-70 4-Stroke HC4645H See Note 1
2001-DATE 90-140 HP 4-Stroke HC4658H See Notes 1, 4
TOHATSU 1990-DATE 40-140 HP HC4645H
YAMAHA 1998 to DATE 40-50 HP HC4645H See Note 2
1998-DATE 60 HP HC4645H See Note 3
1986-DATE 70-90 HP HC4645H See Note 1
1997-DATE 80-150 HP 4-Stroke HC4645H
2000-DATE 25-60 HP 4-Stroke HC4648H See Note 1
2010-DATE 70HP 4-Stroke HC4648H
1997 – 2013 115A 4-STROKE HC4658H
2014 to DATE 115B 4-STROKE HC4645H
YANMAR 1990 to DATE 27-36 HP HC4645H

1. Requires Spacer kit part # HO5090
2. Engine clamp brackets must be cut or ground and the engine through bolted onto the transom, or interference will occur, restricting engine trim and tilt.
3. Steering hook Yamaha Part # 63D-48511-00-4D must be installed
4. Cylinder HC4645 may be used in these applications. The pivot plate will need to be flipped before installation.
Instructions are provided with Owner’s Manual.
5. Johnson 115 HP 2-Stroke engines, require the pivot plate to be flipped. See Note #4.



Part# HC4645H, HC4647H, HC4648H and HC4658H
Balanced cylinder featuring a compact design that fits most splashwells.

Part# HC4600
(No Longer Available. Replacement parts are still available)
Balanced cylinder that fits most splashwells.

Additional Parts Available separately:


Part# HH4314
Super low friction helm for smooth, comfortable steering.


Complete BayStar kit (291561) providing the flexibility to enable the installer the ability to make whatever hydraulic hose length required, without the need for specialist swaged fittings. The two unique re-usable brass end fittings allow the installer to simply cut the hose to length and insert the brass connectors.

The complete kit includes 50-foot length of outboard hose, BayStar helm, BayStar front mount cylinder, hydraulic oil, rubber boot and two re-usable hose fittings.

Cylinder Baystar Steering Kit 291561

Code Description
291071 Cylinder Capacities – SeaStar Solutions Part No. HC4645H Cylinder Model: Front Mount Bore: 1.25″ / 31.7mm Shaft Dia.: .625″ / 15.9mm Stroke: 8″ / 203mm Volume: 118.6cc / 7.2in3 Torque: N/A
291490 Front Helm Pump – 1.4 Front MountDisplacement: 22.9cc / 1.4cu in Relief Valve Setting: 70bar / 1000psi
291902 Hydraulic Oil – 1L
293001 Adjustable Outboard Hose Kit – Rubber BootQty Req.: 1
293050 50′ Seastar Standard Outboard Hose
297332 Re-usable Hose Fitting.

Cylinder Model: Front Mount Bore: 1.25" / 31.7mm Shaft Dia.: .625" / 15.9mm Stroke: 8" / 203mm Volume: 118.6cc / 7.2in3 Torque: N/A

Additional information

Additional information


Price does not include shipping. Product will be shipped via Toll / Australia Post / Courier. Product can also be collected.





Shipping & Delivery
Prices do not include shipping.

Shipping quotes can be obtained by adding products to the cart and inputting your postcode.

$11.60 Brisbane Express - Postcodes 4000-4209, 4270-4299, 4500-4549, 9000-9725 up to 20kg

Boat Hut uses Toll Ipec Priority Service, Australia Post Express Post and Courier's Please. Boat Hut uses Australia Post or DHL International Service for New Zealand deliveries.

Free Local Pickup – by prior arrangement. We don’t always have all the products at our Acacia Ridge premises, but they may be at our warehouse. Warehouse collections can be arranged by prior arrangement - please contact us to discuss.

Order Tracking provided on all orders.

All orders will be processed within 2 business days - except backordered items. If we are unable to meet this timeframe we will contact you to provide details and options. If we are unable to ship your order within 3 business days we will offer you a refund in full or the option to wait for the goods to come into stock.

We are happy to ship to any country - and will provide a quote upon request. All overseas orders must be paid for via Paypal before your order is shipped.

Above pricing refers to regular size items that will fit in courier satchels - oversized items will require a freight quote.

Boat Hut reserves the right to refuse to fulfil an order that has the incorrect postage / freight collected at the time of sale. We will work with you to rectify the matter, if we are unable to come to a resolution then we will provide a refund in full.


Stock Availability
Boat Hut has approx 100,000 product lines coming from a number of warehouses across Australia. Not all of these products are available for a walk-in purchase at Acacia Ridge - most times you will need to make arrangments in advance. Please feel free to contact us to confirm our stock at Acacia Ridge or in our warehouses. We try our best to keep the website up to date with current stock holdings. We will accept back orders on out of stock items. All products are genuine & come with manufacturer's warranties.