Key Switches | Yamaha Outboard

Compatible Applications

Pro Marine 51040 is designed for compatible Yamaha 15-300 HP outboards using the Yamaha 703-series push-to-choke ignition switch found in applicable remote control boxes.

OEM and Cross Reference Numbers

Pro Marine 51040 cross-references the following Yamaha 703-series push-to-choke main ignition switch numbers.

What This Ignition Switch is Used For

The ignition switch is one of the primary electrical controls in a compatible Yamaha remote control box.

Turning the key controls the engine's ignition and starting circuits, allowing the operator to switch the engine off, place the ignition in the run position and engage the starter.

On compatible engines, pressing the key inward activates the push-to-choke function used during engine starting.

Push-to-Choke Function

Pro Marine 51040 is specifically the push-to-choke version of the Yamaha 703-series ignition switch.

Instead of using a separate choke button, the operator pushes the ignition key inward to activate the compatible engine's choke or starting-enrichment circuit.

Designed for Yamaha Remote Control Boxes

This switch is intended for compatible Yamaha remote control-box installations, including applications using the Yamaha 703-series control system.

Yamaha 703 control-box diagrams identify later 703-82510-45-00 as the main switch assembly, replacing earlier versions within this switch family.

Heavy-Duty Marine Ignition Switch Construction

The MP51040 / 703-82510 switch design is built as a marine ignition switch for compatible Yamaha control-box applications.

Published specifications for this switch family identify potted construction and a molded umbrella-style key, helping protect the switch in the marine environment.

Factory-Style Wiring

The replacement switch is designed around the factory Yamaha switch configuration, with wire colors corresponding to the applicable factory color coding.

Even with matching wire colors, verify each connection against the applicable Yamaha wiring diagram before installation.

When Should an Ignition Switch Be Replaced?

A Yamaha ignition switch may need replacement when you experience:

• Intermittent engine starting
• No response when turning the key to START
• Loose or worn key operation
• Failed push-to-choke operation
• Corroded switch wiring or terminals
• Physical damage to the switch body
• Water or corrosion damage inside an older control box
• An ignition switch confirmed faulty during electrical diagnosis

Installation Tips

• Disconnect battery power before servicing the ignition circuit.
• Verify the original OEM switch number before removing the old switch.
• Photograph or label the existing wire connections before disassembly.
• Compare the replacement wiring with the applicable Yamaha wiring diagram.
• Inspect the control-box wiring for corrosion or damaged terminals.
• Do not assume that wire color alone confirms the correct connection.
• Secure wiring so it cannot interfere with the throttle or shift mechanism.
• Reconnect battery power only after installation is complete.
• Test OFF, RUN, START and push-to-choke functions after installation.

Key Features and Benefits

• Pro Marine aftermarket Yamaha ignition switch
• For compatible Yamaha 15-300 HP applications
• Designed for Yamaha 2-stroke and 4-stroke control boxes
• OFF / RUN / START key-switch operation
• Push-to-choke function
• Replacement for Yamaha 703-series main switches
• Crosses to six Yamaha 703-82510 OEM numbers
• Factory-style replacement configuration
• Marine-duty potted switch construction
• Molded umbrella-style key design
• Pro Marine item number 51040
• Manufacturer reference 703-82510-43-00

FAQ

What does Pro Marine 51040 fit?
It fits compatible Yamaha 15-300 HP outboards using the applicable Yamaha 703-series push-to-choke ignition switch. Always verify the OEM number for exact fitment.

Is 51040 for Yamaha 2-stroke or 4-stroke engines?
The switch is used with compatible Yamaha 2-stroke and 4-stroke remote control-box applications.

Does this ignition switch have push-to-choke?
Yes. 51040 is specifically a push-to-choke ignition switch.

How does the push-to-choke feature work?
On a compatible engine, pressing the ignition key inward activates the engine's choke or starting-enrichment circuit.

Does 51040 replace Yamaha 703-82510-43-00?
Yes. 703-82510-43-00 is the manufacturer reference listed for Pro Marine 51040.

Does it replace 703-82510-45-00?
Yes. 703-82510-45-00 is included in the verified interchange family for this push-to-choke switch.

Does it replace 703-82510-40-00?
Yes. 703-82510-40-00 is also included in the verified interchange list.

What is MP51040?
MP51040 is an aftermarket cross-reference number associated with this Yamaha push-to-choke ignition-switch family.

Is this the complete Yamaha remote control box?
No. This listing is for the ignition / main switch assembly, not the complete throttle and shift remote-control box.

Can I choose this switch just by horsepower?
No. Yamaha used different ignition switches across its engine lineup. Use the OEM number on your existing switch or Yamaha parts schematic to verify fitment.

What if I cannot find my original Yamaha part number?
Use the Yamaha OEM parts schematic with your exact model and year to identify the correct ignition-switch number before ordering.

Searchable Part Numbers

51040, MP51040, 703-82510-40-00, 703-82510-41-00, 703-82510-42-00, 703-82510-43-00, 703-82510-44-00, 703-82510-45-00

Searchable Terms

Yamaha ignition switch, Yamaha key switch, Yamaha push to choke switch, Yamaha push-to-choke ignition switch, Yamaha 703 ignition switch, Yamaha 703 key switch, Yamaha control box ignition switch, Yamaha outboard ignition switch, Yamaha 2 stroke ignition switch, Yamaha 4 stroke ignition switch, Yamaha main switch assembly, Yamaha 15HP ignition switch, Yamaha 300HP ignition switch, 703-82510 ignition switch, Pro Marine 51040