Multiflex H2 Helm And SC-18 Steering Cable Light Duty Steering Bundle

The Multiflex MS2 H2, B3B and SC-18 Lite 55 Steering Kit combines a mechanical reduction-gear helm, a black B3B 90° dashboard bezel and a Multiflex SC-18 steering cable in the selected length. Designed for compatible light-duty mechanical steering systems with engines up to 55HP, the system provides approximately 2.5 steering-wheel turns and 228mm / 9in of cable travel. 

Product Identification

• Brand: Multiflex
• Packaged steering-system model: MS2
• Kit part-number format: MS2-XX
• Product category: Mechanical steering helm, bezel and cable kit
• Steering helm: Multiflex H2
• Helm series: Lite 55
• Manufacturer gear classification: Reduction Gear Design
• Manual mechanism description: Internally meshed planetary gear arrangement
• Dashboard bezel: Multiflex B3B
• Bezel colour: Black
• Bezel installation angle: 90°
• Steering cable: Multiflex SC-18
• Cable part-number format: SC-18-XX
• Cable length: Selected when ordering
• Steering-wheel shaft: Standard 19mm / 3/4in tapered shaft
• Steering configuration: Single-cable mechanical rotary steering
• Maximum published system application: Compatible engines up to 55HP
• Steering wheel included: No

The XX suffix identifies the nominal SC-18 cable length in feet. For example, an MS2-12 package contains a nominal 12ft SC-18 cable.

Which Kit Option Is Included?

This listing is for the standard black-bezel MS2 package:

• Multiflex H2 Lite 55 mechanical steering helm
• Multiflex B3B 90° black dashboard bezel
• Multiflex SC-18-XX steering cable in the selected length

What Is Included in the Kit?

• One Multiflex H2 Lite 55 mechanical steering helm
• One Multiflex SC-18 steering cable in the selected length
• One Multiflex B3B 90° black bezel kit
• One SP-T2 spent-cable tube / plastic sleeve
• One MH2-MT dashboard mounting template
• One BC-B3 black plastic bezel cup
• One MB-H2 helm mounting bracket
• Four M6 hex bolts
• One M12 steering-wheel retaining bolt
• Four M6 washers
• One M12 washer
• Eight M6 nyloc nuts
• Two ABS bezel fixing screws
• One MS2-IM installation manual
• One H2-DC helm declaration of conformity
• One SC-18-DC steering-cable declaration of conformity

The package supplies the helm, black 90° bezel, mounting components and selected steering cable required to form the central part of a correctly specified mechanical steering installation.

What Is Not Included?

• Steering wheel
• Steering-wheel hub
• Steering-wheel centre cap
• Engine-specific steering connection kit or drag link
• Outboard engine steering arm
• Tilt-tube service components
• Transom support
• Splashwell mounting kit
• Steering-cable clamp block
• Rudder or tiller link arm
• B3W white bezel
• Dashboard reinforcement
• Installation-specific engine hardware not listed in the package contents
• Professional installation

A compatible steering wheel and any required engine-side connection components must be ordered separately.

How Does the H2 Lite 55 Steering Helm Work?

Multiflex classifies the H2 as a reduction-gear steering helm. The MS2 installation manual describes the internal mechanism as a planetary arrangement using multiple internally meshed gears that rotate around the central helm axis.

When the steering wheel is turned:

• The H2 gear mechanism rotates
• The SC-18 helical cable member is drawn through or pushed out of the helm
• Rotary steering-wheel movement is converted into linear cable movement
• The cable transfers the movement to the engine, rudder or compatible steering linkage

The multi-gear arrangement distributes torque across the internal mechanism, supporting efficient operation and lower feedback than a basic single-gear design. It remains a direct mechanical steering system. Multiflex does not identify the H2 as a non-reaction or mechanically locking no-feedback helm.

Which Boats and Engines Is the Kit Intended For?

The MS2 kit is intended for correctly specified light-duty mechanical steering installations including:

• Compatible engines up to 55HP
• Selected single-outboard powerboats
• Small leisure boats
• Small fishing boats
• RIBs with compatible mechanical steering arrangements
• Single-cable rotary steering installations
• Boats using an SC-18 steering cable
• Dashboard installations requiring a 90° black bezel
• Replacement of a compatible MS2, H2 or SC-18 steering system

The 55HP figure is the maximum published application for the MS2 package. It does not confirm universal compatibility with every 55HP engine or boat. Final suitability depends on:

• The boat manufacturer’s maximum horsepower rating
• Engine type and steering geometry
• Steering load
• Hull design and operating speed
• Steering-cable route
• Required cable length
• Engine-side connection
• Steering-wheel diameter
• Ratings of every component in the completed installation

The system must remain within the rating of the boat and the lowest-rated steering component.

Is the Steering Wheel Included?

No. The steering wheel is not included in this kit.

The Multiflex H2 uses a standard 19mm / 3/4in tapered steering-wheel shaft. A compatible marine steering wheel must be purchased separately.

• Maximum steering-wheel diameter: 406mm / 16in
• Helm-shaft length: 37.5mm
• Shaft profile: Standard 19mm / 3/4in taper
• M12 retaining bolt and washer: Included
• Steering wheel: Not included
• Steering-wheel hub and centre cap: Not included unless supplied with the separately selected wheel

Check clearance around the dashboard, instruments, throttle controls and windscreen before selecting a steering wheel.

Steering-System Performance

• Maximum published application: Compatible engines up to 55HP
• Steering-wheel movement: Approximately 2.5 turns
• SC-18 cable travel: 228mm / 9in
• MS2 system minimum cable bend radius: 250mm / 9.8in
• Maximum working load at tiller end: 5,000N / 500kg
• Maximum steering-wheel diameter: 406mm / 16in
• Helm-shaft length: 37.5mm
• Steering-wheel shaft: Standard 19mm / 3/4in taper
• Number of steering cables: One
• Dashboard installation angle: 90°
• Helm mounting positions: Five selectable positions at 45° intervals
• Published operating ambient temperature: -20°C to +60°C
• Feedback characteristic: Lower-feedback mechanical reduction system
• Non-reaction function: Not specified

What Are the Features of the SC-18 Steering Cable?

• Mechanical push-pull steering cable
• Directly specified for the Multiflex H2 helm
• Used in the Multiflex MS2 Lite 55 package
• Helical inner member at the helm end
• Threaded helm-end cable fitting
• Stainless-steel output ends
• 228mm / 9in system travel
• Length identified by the XX suffix in feet
• Available in multiple nominal foot lengths
• Exceeds ISO 9775
• Designed for marine mechanical steering systems
• Multiflex cross-reference to SeaStar / Dometic SSC131
• Multiflex cross-reference to Ultraflex M58

The standalone SC-18 product page publishes an 8in minimum bend radius. However, the dedicated MS2 installation manual specifies a larger 250mm / 9.8in minimum bend radius for the complete H2 and SC-18 system. The more conservative 250mm / 9.8in figure should be followed when installing this kit.

Does the SC-18 Cable Need an Adaptor?

No separate adaptor is identified between the included Multiflex H2 helm and SC-18 cable.

The SC-18 cable connects by:

• 1. Inserting the loose helical inner member into the H2 helm
• 2. Rotating the steering wheel anticlockwise to draw the cable into the gear mechanism
• 3. Screwing the cable-end fitting into the helm nut
• 4. Tightening the cable fitting to the specified 6Nm torque
• 5. Covering the loose helical section with the supplied SP-T2 plastic sleeve

Multiflex publishes the following cross-references:

• H2 helm: SeaStar / Dometic SH8050
• H2 helm: Ultraflex T67
• SC-18 cable: SeaStar / Dometic SSC131
• SC-18 cable: Ultraflex M58
• B3B bezel: SeaStar / Dometic SB39452P
• B3B Ultraflex equivalent: None listed

Cross-references are selection guides rather than guarantees of automatic interchangeability. Confirm the helm-end connection, cable retention method, travel, cable length, dashboard dimensions and engine-side fitting before substituting another brand.

How Do You Select the Correct SC-18 Cable Length?

Measure dimensions A, B and C along the proposed cable route in centimetres. Count the number of 90° bends and identify whether the cable will pass through the engine tilt tube or use a transom or splashwell support.

For installation through an engine tilt tube:

• 1. Add dimensions A + B + C.
• 2. Subtract 10cm for each 90° bend.
• 3. Add 30.5cm for the engine tilt-tube installation.
• 4. Divide the result by 30.5 to convert the measurement to feet.
• 5. Round up to the next whole-foot cable length.

Formula: A + B + C − 10cm per 90° bend + 30.5cm.

For transom-support or splashwell mounting:

• 1. Add dimensions A + B + C.
• 2. Subtract 10cm for each 90° bend.
• 3. Divide the result by 30.5 to convert the measurement to feet.
• 4. Round up to the next whole-foot cable length.

Formula: A + B + C − 10cm per 90° bend.

For replacement installations, check the complete model and length marking on the removed cable wherever possible. Do not order a cable shorter than the calculated length.

B3B Bezel Kit

The included Multiflex B3B is a black 90° dashboard bezel manufactured from engineering plastic. It mounts between the steering wheel and dashboard, covers the helm opening and supports the H2 installation hardware.

The supplied bezel assembly includes:

• B3B 90° black bezel kit
• BC-B3 black plastic bezel cup
• MB-H2 mounting bracket
• Four M6 bracket bolts
• Four M6 washers
• Eight M6 nyloc nuts
• One M12 steering-wheel retaining bolt
• One M12 retaining washer
• Two ABS bezel fixing screws

The alternative B3W 90° white bezel is not included in this listing.

H2 Helm Dimensions

• Main helm-housing width: 133mm / 5.23in
• Maximum overall width including side fitting: 159mm / 6.25in
• Overall housing height: 136mm / 5.35in
• Helm-housing depth: 77mm / 3.03in
• Overall depth to the end of the steering shaft: 146mm / 5.74in
• Steering-wheel shaft length: 37.5mm

These dimensions should be checked against the available dashboard and rear-console space before installation.

Construction and Compliance

• Reduction-gear mechanical steering design
• Internally meshed planetary gear arrangement described in the MS2 manual
• High-pressure die-cast aluminium-alloy helm cover
• High-pressure die-cast zinc-alloy gear and shaft
• Standard 19mm / 3/4in tapered steering-wheel shaft
• Adjustable helm mounting position
• Engineering-plastic B3B bezel
• Stainless-steel SC-18 output ends
• Mechanical helical cable-to-helm interface
• Single-cable steering configuration
• SC-18 cable exceeds ISO 9775
• MS2 conformity with Recreational Craft and Personal Watercraft Directive 2013/53/EU
• MS2 conformity in accordance with EN ISO 8848:1995/A1:2000
• Published operating range of -20°C to +60°C

Installation Notes

The Multiflex MS2 installation manual specifies:

• Dashboard thickness: 12.7–54mm / 0.5–2.1in
• Minimum clearance behind dashboard: 130mm
• Central dashboard cut-out: 83mm / 3.25in
• Dashboard mounting holes: Three holes, each 10mm / 3/8in
• Bezel-bracket mounting torque: 15Nm
• Helm-to-bracket mounting torque: 25Nm
• SC-18 cable fitting torque: 6Nm
• MS2 minimum cable bend radius: 250mm / 9.8in
• Cable support interval: Approximately every 2m / 6ft
• Helm mounting positions: Five positions at 45° intervals

Route the cable away from:

• Sharp dashboard openings
• Cutting edges
• Heat sources
• Electrical wiring
• Moving engine components
• Areas where the conduit could be crushed
• Tight or unsupported bends

Do not secure the steering cable to electrical wiring.

After installation, confirm that:

• The selected SC-18 cable length is correct
• A compatible steering wheel is securely fitted to the tapered shaft
• The SC-18 cable is fully engaged with the H2 helm
• The threaded cable fitting is securely retained
• The spent-cable sleeve covers the exposed helical cable section
• The cable remains above the 250mm system bend-radius limit
• Clockwise wheel movement steers the boat to starboard
• Anticlockwise wheel movement steers the boat to port
• The engine or rudder reaches its complete steering range
• No interference occurs with the transom, splashwell or engine
• Full steering movement remains available with an outboard lowered and tilted
• The cable does not bottom out before the steering mechanism reaches its stop
• Bolts, nuts and fasteners are rechecked after the first two operating hours

Multiflex specifies servicing every 30 days for saltwater use and every 90 days for freshwater use, with specialist inspection at least every two years. Marine steering is safety-critical, and installation should be completed by a competent marine technician following the current instructions.

Key Features

• Official Multiflex MS2 packaged steering system
• H2 Lite 55 mechanical steering helm
• SC-18 steering cable supplied in the selected length
• B3B 90° black bezel kit included
• Intended for compatible engines up to 55HP
• Single-cable mechanical steering configuration
• Reduction-gear helm classification
• Internally meshed planetary gear arrangement
• Lower-feedback mechanical operation
• Approximately 2.5 steering-wheel turns
• 228mm / 9in steering-cable travel
• 250mm / 9.8in MS2 system minimum bend radius
• 5,000N / 500kg maximum tiller-end working load
• Maximum steering-wheel diameter of 406mm / 16in
• Standard 19mm / 3/4in tapered helm shaft
• 37.5mm helm-shaft length
• Five selectable helm positions at 45° intervals
• High-pressure die-cast aluminium-alloy helm cover
• High-pressure die-cast zinc-alloy gear and shaft
• Stainless-steel SC-18 cable output ends
• Engineering-plastic B3B bezel
• Direct H2-to-SC-18 connection
• SC-18 exceeds ISO 9775
• MS2 conforms with Directive 2013/53/EU in accordance with EN ISO 8848
• Selected cable length identified by the XX suffix
• Spent-cable tube and mounting hardware included
• Engine-specific connection components not included
• Steering wheel not included

Frequently Asked Questions

Is a steering wheel included? No. The package includes the H2 helm, B3B black bezel, selected SC-18 cable and the listed mounting hardware. A compatible marine steering wheel must be purchased separately.

Is the B3B bezel included? Yes. One B3B 90° black bezel kit is included.

Can the kit be supplied with a white bezel? The B3W 90° white bezel is an available alternative, but it is not included in the standard B3B package described in this listing.

Which steering wheel fits the H2 helm? Use a compatible marine steering wheel with a standard 19mm / 3/4in tapered hub. The wheel must not exceed 406mm / 16in in diameter.

Is the H2 a no-feedback helm? No non-reaction or locking no-feedback mechanism is specified. The internal reduction arrangement is designed to provide lower feedback while retaining direct mechanical control.

Can this kit be installed on any 55HP engine? No. The 55HP figure is the maximum published system application. Suitability also depends on the boat rating, engine steering geometry, cable route, operating conditions and engine-side connection.

Is the SC-18 cable included? Yes. One SC-18 cable in the length selected when ordering is included.

Does the H2 require an adaptor for the SC-18 cable? No separate adaptor is identified for the standard H2 and SC-18 combination.

What bend radius should be used? Use the MS2 manual’s system-specific minimum of 250mm / 9.8in. Although the standalone SC-18 page lists 8in, the complete-system manual publishes the larger limit.

Can an Ultraflex M58 or SeaStar SSC131 replace the SC-18? Multiflex lists M58 and SSC131 as cross-references. Confirm the exact helm connection, retention method, cable travel, selected length and engine-side fitting before substitution.

Is an engine connection kit included? No. Any required drag link, steering arm, clamp block, transom support or splashwell mounting component must be selected separately.