Sea-Dog 420350-1
Stamped brass; long shaft; 3 screw terminals. For standard keyed marine ignition; stamped-brass housing and long mounting shaft.
Identify Sea-Dog Marine Ignition Switches by Shaft & Choke
An unmarked boat ignition switch should be identified by its shaft length, back-terminal arrangement and whether pressing the key engages a choke. Sea-Dog makes a brass long-shaft model, covered and uncovered polymer versions, and short-shaft magneto-style choke switches. Similar keyed faces do not establish interchangeability.
Identify the original key switch
The table compares exact manufacturer numbers and separates electrical ratings from mechanical fit. On small screens, scroll horizontally to see all specifications.
| Sea-Dog MPN | Operation | Shaft | Max. panel | Connections | Cap |
|---|---|---|---|---|---|
| 420350-1 | Off–Ignition–Start | Long | 1⅛ in | 3 screw terminals | No boot |
| 420360-1 | Off–Ignition–Start | Long | 1⅛ in | 3 screw terminals | No boot |
| 420365-1 | Off–Ignition–Start | Long | 1⅛ in | 3 screw terminals | Boot included |
| 420366-1 | Off–Ignition–Start | Short | ⅝ in | 3 screw terminals | Boot included |
| 420381-1 | Off–Ignition–Start + push-to-choke | Short | ⅝ in | 6 screw terminals | No boot |
| 420382-1 | Off–Ignition–Start + push-to-choke | Short | ⅝ in | 5 screws + 1 boss | No boot |
| 420383-1 | Off–Ignition–Start + push-to-choke | Short | ⅝ in | 6 wires | No boot |
Important fit distinction: The choke models 420381/382/383 are not simply alternative body colours of the ordinary three-position switches. They add push-to-choke control and use different six-connection arrangements. All listed ignition shafts are 13/16 inch diameter; the maximum allowed panel thickness varies with shaft length. The switch includes two keys, but key compatibility with an old ignition is not assumed.
Electrical rating: Sea-Dog specifies 15A at 12V DC for the ignition circuit and 30A at 12V DC for the solenoid circuit. The push-to-choke models add a 7A at 12V DC choke circuit. The listed standard and choke versions have different electrical connections.
Manufacturer dimension and specification references: brass ignition, polymer ignition, screw-terminal choke, wire-lead choke. These include the original switch and breaker drawings.
What to inspect before replacement
- Read the original ignition switch's complete number and confirm whether the engine uses a magneto-style choke circuit.
- Identify long versus short shaft: 1⅛-inch maximum panel thickness for long versions, ⅝-inch for short versions.
- Count and compare electrical connections: three screw terminals, six screw terminals, five screws plus boss, or six wire leads.
- Verify whether the original requires a protective boot and whether the selected product supplies one.
- Isolate electrical power, follow the engine wiring diagram and confirm the choke and starter circuits before connecting anything.
Matching part-number listings
Each card opens an exact UsedRVParts product listing. Check the stated condition and current availability; viewing and pickup in Kelowna are by appointment.
Sea-Dog 420360-1
Polypropylene; long shaft; 3 screw terminals. Polypropylene long-shaft ignition switch with no rubber cap included.
Sea-Dog 420365-1
Polypropylene; long shaft; 3 screw terminals. Long-shaft polypropylene ignition switch supplied with protective rubber boot.
Sea-Dog 420366-1
Polypropylene; short shaft; 3 screw terminals. Short-shaft polypropylene option for a thinner panel; rubber boot supplied.
Sea-Dog 420381-1
Polypropylene; short shaft; 6 screw terminals. Magneto-style push-to-choke switch with six screw connections.
Sea-Dog 420382-1
Polypropylene; short shaft; 5 screws + 1 boss. Magneto-style choke switch with a five-screw and one-boss arrangement.
Sea-Dog 420383-1
Polypropylene; short shaft; 6 wires. Magneto-style push-to-choke switch with six wire leads rather than screw connections.
Related Sea-Dog electrical guides
Continue with compact SD-13 breakers, panel-mount SD-17 breakers, surface-mount SD-17 breakers. For more general electrical switching see our Sea-Dog toggle-switch identification guide. For inline fuse components, visit the Sea-Dog AGC fuse-holder identification guide.
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