Ultraflex HYCO-I Inboard Hydraulic Steering Kit

The Ultraflex HYCO-I 40243E is a packaged hydraulic steering system for compatible single-engine inboard boats. It combines the UP20F 20cc/rev front-mount helm, UC69-I balanced 69cc inboard cylinder and two litres of Ultraflex OL150 hydraulic oil, producing approximately 3.5 steering-wheel turns lock to lock. Choose the kit without hoses or a package with the required hydraulic-hose length. The steering wheel is not included.

Special-order notice: The HYCO-I Inboard Hydraulic Steering Kits are special-order products and are subject to a supplier lead time. Contact us for the current estimated lead time before ordering. These models should not be ordered on the assumption of immediate dispatch.

Product Identification

• Brand: Ultraflex
• Product range: HYCO-I
• Product category: Inboard hydraulic steering kit
• Model: HYCO-I
• Manufacturer part number: 40243E
• Supplier catalogue code: 4-48040
• Helm model: UP20F
• Helm part number: 43180Y
• Helm supplier code: 4-48003
• Cylinder model: UC69-I
• Cylinder part number: 39782E
• Cylinder supplier code: 4-48030
• Hydraulic oil: Ultraflex OL150
• Oil part number: 42398X
• Oil supplier code: 4-47067
• Oil quantity: 2 litres
• Steering configuration: Single helm and single cylinder
• Approximate wheel turns: 3.5 lock to lock
• Application: Compatible single-engine inboard boats
• Maximum engine power: Up to 150HP, subject to rudder-torque calculation
• Maximum boat speed: 25mph
• Hose options: Kit without hoses or selected KIT OB hose length
• Steering wheel: Not included

What Is This Hydraulic Steering Kit Used For?

The Ultraflex HYCO-I converts steering-wheel movement into hydraulic pressure, moving the UC69-I cylinder and the connected rudder arm.

It is intended for:

• Compatible single-engine inboard boats
• Single steering-station installations
• Single-cylinder steering systems
• New hydraulic steering installations
• Replacement of a complete compatible HYCO-I system
• Boats operating within the stated speed, power and rudder-torque limits

The system is not selected from engine horsepower or boat length alone. The rudder load, tiller-arm length, steering angle, vessel speed and hull characteristics must also be checked.

The UC69-I cylinder must be used with one helm and one cylinder. It is not the correct cylinder for a dual-station or dual-cylinder installation.

What Is Included?

The standard HYCO-I kit includes:

• One Ultraflex UP20F front-mount hydraulic helm pump
• One Ultraflex UC69-I balanced inboard hydraulic cylinder
• Two 1-litre bottles of Ultraflex OL150 hydraulic steering oil
• Helm fittings supplied with the UP20F
• UC69-I cylinder assembly with mounting bracket and ball-joint connection

Hose inclusion depends on the selected option:

• Kit only: Hydraulic hoses are not included
• Hose-inclusive option: The selected Ultraflex KIT OB hose pair is added to the package

Not included:

• Steering wheel
• Hydraulic hoses when the kit-only option is selected
• Rudder or tiller arm
• Rudder-arm connection bolt and boat-specific mounting hardware
• Second helm pump
• Second hydraulic cylinder
• Autopilot connection components
• Additional hydraulic oil beyond the supplied two litres
• Boat-specific structural supports

Which Boats and Installations Are Compatible?

The current Ultraflex UC69-I manual specifies the cylinder for:

• Compatible inboard engines up to 150HP
• One steering helm
• One hydraulic cylinder
• A 70-bar / 1000psi Ultraflex UP-series helm
• Compatible rudder and tiller-arm arrangements
• Installations where the calculated rudder torque remains within the cylinder rating

The HYCO-I package uses the UP20F, which Ultraflex specifically lists as compatible with the UC69-I cylinder.

Before ordering, confirm:

• The boat has a single inboard engine
• The installation uses one steering station
• The installation uses one hydraulic cylinder
• Maximum boat speed does not exceed 25mph
• The rudder torque is within the UC69-I rating
• The tiller-arm length and steering angle suit the cylinder stroke
• The selected hose length reaches the helm and cylinder without tension
• The steering wheel has a standard 19mm / 3/4in tapered hub
• The wheel diameter does not exceed 508mm / 20in
• The mounting structure can withstand the cylinder load

This kit is not suitable for an installation requiring two steering stations, two cylinders or a higher-capacity inboard cylinder.

Published Boat-Length Guidance

Published length guidance differs between current manufacturer and UK distributor data:

• Current Ultraflex product page: Up to approximately 10m / 32.8ft
• UK distributor guidance for kit code 4-48040: Approximately 7.5–8m / 24–26ft
• Maximum stated speed in both cases: 25mph

Boat length is only a general guide. A long, lightly loaded displacement boat may impose less rudder torque than a shorter, faster vessel with a large rudder.

For conservative selection, use the 7.5–8m UK guidance unless the vessel's rudder torque, tiller-arm geometry and complete system specification have been checked against the current Ultraflex technical data.

How Many Steering-Wheel Turns Does It Provide?

The HYCO-I combines:

• UP20F helm displacement: 20cc per steering-wheel revolution
• UC69-I cylinder volume: 69cc

The approximate steering-wheel movement is therefore:

• 69cc ÷ 20cc/rev = approximately 3.45 turns
• Published package description: Approximately 3.5 turns lock to lock

The final number of turns can vary slightly according to installation, filling, bleeding and cylinder travel.

Which Hose Length Should I Choose?

This listing can be supplied as a kit without hoses or with a selected Ultraflex KIT OB hose pair.

Available listing options include:

• Kit without hydraulic hoses
• 4.5m hose kit
• 5m hose kit
• 5.5m hose kit
• 6m hose kit
• 6.5m hose kit
• 7m hose kit
• 7.5m hose kit
• 8m hose kit
• 9m hose kit

Measure the complete installed route from the helm to the cylinder rather than taking a straight-line measurement.

Allow sufficient length for:

• Routing around bulkheads and structural members
• Smooth bends
• Movement and vibration
• Connection to both helm ports
• Connection to both cylinder ports
• Access for installation and servicing

Do not order a hose length that requires the hoses to be stretched, sharply bent or routed against hot, moving or abrasive components.

UP20F Helm Pump Details

The Ultraflex UP20F is a five-piston, front-mount hydraulic steering helm.

• 20cc / 1.2cu.in displacement per revolution
• Five-piston pumping mechanism
• Built-in non-return or lock valve
• Positive rudder lock
• Integral over-pressure relief valve
• 70-bar / 1000psi relief-valve setting
• Standard 19mm / 3/4in tapered stainless-steel shaft
• Corrosion-resistant composite reservoir
• Adjustable 90° fittings for 3/8in hydraulic hose
• Accessible lock valve and shaft seal
• Maximum steering-wheel diameter of 508mm / 20in
• Front-dashboard mounting
• Optional X74 square flange for an intermediate mounting position

The optional X74 flange is sold separately.

UC69-I Cylinder Details

The Ultraflex UC69-I is a balanced, double-acting hydraulic cylinder for compatible inboard steering installations.

• Cylinder volume: 69cc / 4.2cu.in
• Published torque: 32kgm / 2783lb.in
• Output force: 168kg / 371lb
• Internal diameter: 25mm / 0.98in
• Stroke: 150mm / 5.9in
• Hydraulic connection: 3/8in
• Cylinder type: Balanced
• Steering movement: Equal turns from port to starboard and starboard to port
• Installation: Single helm and single cylinder only

The cylinder connects to the rudder or tiller arm through its ball joint. Correct tiller-arm length and steering angle are required to keep the operating torque within the permitted range.

Which Steering Wheels Are Compatible?

The UP20F helm has a standard 19mm / 3/4in tapered stainless-steel steering-wheel shaft.

Before choosing a wheel, confirm:

• The wheel has a standard 3/4in tapered hub
• The wheel diameter does not exceed 508mm / 20in
• The hub seats fully on the shaft taper
• The shaft key and retaining hardware are correctly installed
• The wheel can rotate through the complete steering range
• The wheel does not contact the dashboard, instruments or controls

A steering wheel is not supplied with the HYCO-I kit.

Construction and Design

• Five-piston hydraulic helm
• Built-in helm lock valve
• Integral over-pressure protection
• Stainless-steel steering-wheel shaft
• Corrosion-resistant composite helm reservoir
• Balanced, double-acting inboard cylinder
• Aluminium cylinder construction
• Equal port and starboard steering travel
• 3/8in hydraulic connections
• Two litres of Ultraflex OL150 oil
• Hose-length options for different boat installations
• Components designed for the marine environment

Standards and Operating Range

Ultraflex states that its hydraulic steering systems are designed in conformity with:

• UNI EN ISO 10592
• ABYC P21
• Recreational Craft Directive 2013/53/EU requirements

The stated ambient operating-temperature range is:

• Minimum: -18°C / 0°F
• Maximum: +77°C / +170°F

The complete installation must use compatible components and follow the current Ultraflex instructions. Component conformity does not validate an incorrectly selected rudder, tiller arm, hose arrangement or mounting structure.

Installation and Use

Installation should be completed by a qualified marine technician familiar with hydraulic steering systems.

Before installation:

• Confirm the boat, engine and rudder application
• Calculate or verify the required rudder torque
• Confirm the tiller-arm length and steering angle
• Check that the cylinder reaches its end stroke before the rudder reaches an unsuitable mechanical stop
• Select the correct hose length
• Confirm sufficient space behind the dashboard for the UP20F
• Confirm suitable cylinder-mounting structure
• Inspect all components for damage or contamination

During installation:

• Install the helm with the filler opening in the correct upper position
• Mount the cylinder so that its movement remains correctly aligned
• Keep the cylinder oil fittings in the required upper position
• Use suitable corrosion-resistant mounting hardware
• Route hoses without sharp bends, abrasion or heat exposure
• Do not rotate or loosen factory-positioned cylinder fittings
• Use only the hydraulic fluid specified by Ultraflex
• Do not use PTFE tape where fragments could enter the hydraulic circuit

Fill and bleed the system until the discharged oil is free from visible air bubbles.

After installation, check that:

• The wheel turns smoothly in both directions
• The cylinder reaches its complete permitted stroke
• The rudder moves evenly to port and starboard
• No abnormal free movement is present
• No fluid leaks are visible
• Hoses remain clear of moving or hot components
• The helm remains securely attached to the dashboard
• The cylinder bracket and ball-joint connection remain secure
• The oil level remains correct after repeated operation

Marine steering is safety-critical. The boat must not be operated with fluid leakage, trapped air, loose mounting hardware, damaged hoses or restricted cylinder movement.

Frequently Asked Questions

Are hydraulic hoses included?

Only when a hose-inclusive option is selected. The basic 4-48040 / 40243E kit is supplied without hydraulic hoses.

Is the steering wheel included?

No. A compatible steering wheel with a standard 3/4in tapered hub is required separately.

Can the HYCO-I be used with two steering stations?

No. The current UC69-I manual specifies one helm and one cylinder.

Is it suitable for engines above 150HP?

No. The UC69-I is specified for compatible single inboard engines up to 150HP, and the rudder-torque requirement must also remain within the cylinder rating.

Can boat length alone be used to select the system?

No. Published length guidance is approximate. Rudder size, tiller-arm length, steering angle, hull type and boat speed also affect the steering load.

Which hydraulic oil should be used?

Ultraflex OL150 hydraulic steering oil is specified. Two litres are included.

Key Features

• Packaged hydraulic steering system for compatible inboard boats
• Ultraflex HYCO-I model
• Manufacturer part number 40243E
• Supplier code 4-48040
• UP20F 20cc/rev front-mount helm
• UC69-I balanced 69cc cylinder
• Approximately 3.5 turns lock to lock
• Suitable for compatible single inboard engines up to 150HP
• Single helm and single cylinder only
• Maximum stated boat speed of 25mph
• 70-bar / 1000psi system components
• 150mm / 5.9in cylinder stroke
• 25mm / 0.98in cylinder bore
• 168kg / 371lb published cylinder output force
• Standard 19mm / 3/4in tapered steering-wheel shaft
• Maximum steering-wheel diameter of 508mm / 20in
• Two litres of Ultraflex OL150 oil included
• Available without hoses or with selected hose length
• Steering wheel supplied separately
• Installation must be matched to the rudder torque and tiller-arm geometry

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