OFS Complete Accessories Kit, OFS-Pro Version | Reverso 35-3957-01-04

Reverso 35-3957-01-04 OFS Pro Complete Accessories Kit | Model OFS-1-12 Vpro | Automatic Outboard Flushing System

The Reverso #35-3957-01-04 is the complete accessories kit for the Reverso OFS Pro Automatic Outboard Flushing System — Model OFS-1-12 Vpro. The OFS Pro automatically flushes the outboard engine's cooling system on a preset cycle with the engine off, eliminating manual hose connections after every use. The Pro version adds service mode for manual override during maintenance and winterizing. IP67 and IP69K waterproof rated, ignition protected, and built for permanent installation. Requires Reverso fitting kit 35-3955-01-01 (sold separately). Upgrades OFS Version 3.0 (35-3861-01).

Part Details:

• Part Number: 35-3957-01-04 (Reverso)
• SKU: REVERSO-35-3957-01-04
• Manufacturer: Reverso
• Model: OFS-1-12 Vpro (OFS Pro)
• Type: Automatic Outboard Flushing System — Complete Accessories Kit
• Flush Cycle Timing: 7.5 or 15 minutes (preset)
• Operation: Engine off
• Engine Position: Vertical or tilted
• Voltage: 12V DC (continuous supply required)
• Waterproof Rating: IP67 and IP69K
• Ignition Protected: Yes
• Housing: Marine-grade starboard mounting base, high-impact plastic cover
• Installation: Permanent — bilge, transom, or rigging compartment
• Required Accessory: Reverso fitting kit 35-3955-01-01 (sold separately)
• Upgrades: OFS Version 3.0 (35-3861-01)
• Condition: New

Additional Information

What the OFS Pro Does — Automatic Engine Flushing:

The Reverso OFS Pro automatically flushes the outboard engine's raw water cooling system with fresh water after each use. Traditional engine flushing requires the operator to connect a garden hose to a flush port or use ear muffs while running the engine — a step that is frequently skipped, especially after short trips or in multi-engine installations. The OFS Pro eliminates this by running a timed flush cycle automatically with the engine off, using a permanently installed system plumbed to the engine's built-in flushing ports. No manual hose connection is required after the initial installation.

Requires Built-In Engine Flushing Ports:

The OFS Pro is designed for modern outboard engines equipped with built-in flushing ports — the internal ports that allow fresh water to be connected directly to the engine's cooling system without using ear muffs or running the engine in a tank. Confirm your outboard has built-in flushing ports before purchasing. Most modern four-stroke outboards from major manufacturers (Yamaha, Honda, Mercury, Suzuki, Evinrude/BRP) include built-in flush ports; older two-stroke engines may not.

OFS Pro vs. OFS Version 3.0 — What's New:

The OFS-1-12 Vpro (35-3957-01-04) is the current-generation upgrade from the OFS Version 3.0 (35-3861-01). Key additions in the Pro version:

• Service mode — manual override capability for extended flushing during maintenance, winterizing, or other service tasks beyond the standard timed cycle
• IP69K rating — in addition to IP67 (temporary immersion), IP69K adds high-pressure, high-temperature wash-down resistance; the OFS Version 3.0 was rated IP67 only
• Remote switch option — optional waterproof remote start button mountable anywhere on deck (sold separately: Reverso 35-3954-02)

Flush Cycle Timing — 7.5 or 15 Minutes:

The OFS Pro offers two preset flush cycle durations — 7.5 minutes for standard post-use flushing and 15 minutes for more thorough flushing after heavy saltwater exposure. The preset cycle runs automatically with the engine off; service mode allows manual extension beyond the timed cycle for maintenance or winterizing procedures.

IP67 + IP69K — Dual Waterproof Rating:

The OFS Pro carries both IP67 (fully dust-tight; temporary water immersion to 1 meter for 30 minutes) and IP69K (high-pressure, high-temperature water jet resistance) ratings. This makes the unit appropriate for bilge, transom, and rigging compartment installations subject to spray, wash-down, and incidental immersion. Ignition protected per ABYC standards for installation in gasoline fuel vapor zones.

Required Fitting Kit — 35-3955-01-01 (Sold Separately):

The OFS Pro requires the Reverso fitting kit 35-3955-01-01 for engine connection. This fitting kit is sold separately and is not included in the 35-3957-01-04 accessories kit. Do not confuse with the 35-3955-01-02 (2-engine Pro fittings kit) or the 35-3955-02 (standard OFS fittings kit) — confirm you are ordering 35-3955-01-01 for this system. Contact us at MacombMarineParts.com to add the fitting kit to your order.

Optional Accessories — Build Out Your System:

The OFS Pro can be expanded with optional accessories to customize the installation for your vessel layout:

• Inlet hose kit: Reverso 35-3951-03 OFS Inlet Hose Kit (3 ft.)
• Deck kit: Reverso 35-3952-01 OFS Quick Disconnect Deck Kit
• Remote switch: Reverso 35-3954-02 OFS Remote Switch with 6 ft. Harness
• Faceplate mounting kit: Reverso 35-3952-03 OFS Faceplate Mounting Kit

Installation Overview:

The OFS Pro mounts permanently in the bilge, transom, or rigging compartment — any protected location accessible for wiring and hose connections. Requires a continuous 12V DC power supply (not switched with the ignition). The unit is plumbed to the engine via the Reverso fitting kit (35-3955-01-01) at the engine's built-in flush port connections. Suitable for new boat builds and retrofit installations.

Installation Notes:

• Confirm your outboard has built-in flushing ports before ordering
• Order fitting kit 35-3955-01-01 separately — required for installation; not included
• Route 12V power from a continuous (non-switched) circuit — the system must remain powered independently of the ignition
• Install in a location that is protected from direct immersion but accessible for service
• Refer to Reverso OFS Pro installation documentation for complete wiring, plumbing, and commissioning procedure

Frequently Asked Questions

1. Does my outboard engine need built-in flushing ports to use the OFS Pro?
Yes — the Reverso OFS Pro is designed specifically for outboards with built-in flushing ports. These are internal ports that allow direct fresh water connection to the engine's cooling system. Most modern four-stroke outboards include them; confirm with your engine's documentation or dealer before purchasing.

2. What fitting kit does the OFS Pro require?
The OFS Pro requires Reverso fitting kit 35-3955-01-01, sold separately. This is not included in the 35-3957-01-04 accessories kit. Do not substitute the 35-3955-01-02 (2-engine kit) or 35-3955-02 (standard OFS kit). Contact us at MacombMarineParts.com to add the fitting kit to your order.

3. What is service mode on the OFS Pro?
Service mode is a manual override that allows the operator to run the flushing system beyond the standard timed cycle — useful for extended flushing during maintenance, winterizing, or other service procedures that require more than the standard 7.5 or 15-minute flush cycle.

4. What is the difference between OFS Pro and OFS Version 3.0?
The OFS Pro (OFS-1-12 Vpro) adds service mode, IP69K waterproof rating (high-pressure wash-down, vs. IP67 only on Version 3.0), and remote switch capability. It is the current-generation upgrade of the OFS Version 3.0 (35-3861-01).

5. What power supply does the OFS Pro require?
A continuous 12V DC power supply. The circuit must remain live independently of the ignition switch — do not wire to a switched ignition circuit, as the system must be able to operate with the engine off.

6. Can I add a remote switch to trigger the flush cycle from the helm?
Yes — the OFS Pro supports an optional waterproof remote start button. See the Reverso 35-3954-02 OFS Remote Switch with 6 ft. Harness.