Sierra International MP39090 Ignition Switch 3 Position Magneto Review

Uncovering the Sierra International MP39090 Ignition Switch 3 Position Magneto: Real Review

For anyone dealing with marine engines or older workshop equipment, a reliable ignition switch is non-negotiable. This is where the Sierra International MP39090 Ignition Switch 3 Position Magneto comes into play, a robust component designed for durability and straightforward functionality. My own journey to this particular switch began with a frustrating failure on an older boat’s outboard motor; the original ignition switch had corroded beyond repair, leaving me stranded and with a critical need for a replacement that could withstand the harsh marine environment. I considered a generic automotive switch, but the thought of its susceptibility to saltwater and vibration quickly dismissed that idea. The prompt arrival and solid feel of this Sierra International unit offered an immediate sense of relief and professionalism.

Real-World Testing: Putting Sierra International MP39090 Ignition Switch 3 Position Magneto to the Test

My testing grounds for this ignition switch were primarily my workshop and a small coastal inlet where I keep my boat. Installation was straightforward on the boat’s console; the 7/8″ hole size accommodated the existing opening perfectly, and the long 1-1/8″ maximum panel thickness length meant it secured snugly to the fiberglass. The 6 screw tab terminal system, while requiring a bit of wire management, was secure and allowed for positive connections for ignition, start, and choke functions. I experienced no issues with it during initial setup, finding the three distinct positions – Off-Run-Start – to be clearly defined and satisfyingly tactile.

Over the course of several weeks, I put this switch through its paces. This involved numerous starts and stops of the outboard motor, including a few instances where I had to rapidly engage the starter. The switch handled these demands without any sign of faltering, and the push to choke feature worked smoothly every time, ensuring easy cold starts. I also intentionally exposed it to a light sea spray and the general humidity of a marine environment; the maximum corrosion protection that eliminates oxidation and the inner seal between the cylinder lock and contact plate seem to be holding up remarkably well, with no signs of pitting or degradation. The non-conductive housing also provided peace of mind, eliminating any concerns about accidental shorts against the metal console.

In terms of durability, after dozens of engine cycles and a couple of minor bumps against my toolbox in the workshop, the switch remains as solid as the day I installed it. There’s no looseness in the tumbler, and the detents for each position feel as crisp as they did initially. Maintenance has been non-existent, which is precisely what I want in a marine component; it’s designed to be installed and forgotten, save for its regular operation. Compared to a previous, less robust switch I replaced on a different project, this Sierra International MP39090 Ignition Switch 3 Position Magneto is clearly a step up in build quality and perceived longevity.

Breaking Down the Features of Sierra International MP39090 Ignition Switch 3 Position Magneto

The technical specifications of the Sierra International MP39090 Ignition Switch 3 Position Magneto are geared towards reliable performance in demanding applications. Its 3-Position Magneto design, coupled with a 6 screw tab terminal system, offers a versatile setup for various ignition circuits. The switch is rated for 7 Amps at 12 VDC for the choke, 15 Amps at 12 VDC for ignition, and a substantial 30 Amps at 12 VDC for the solenoid. These ratings are crucial for ensuring that the switch can handle the electrical loads without overheating or failing, particularly during the high current draw of engine starting.

Functionally, this ignition switch excels at its primary task. The Off-Run-Start positions are clearly delineated, providing unambiguous control over the engine’s state. The push to choke mechanism integrates seamlessly, making it effortless to enrich the fuel mixture for cold starts, a feature I particularly appreciated during those early morning fishing trips. Its performance has been consistently reliable; starting the engine is a decisive action, and turning it off is equally abrupt. The maximum corrosion protection is not just marketing jargon; the visible sealing and material choices suggest a design intended to withstand the elements.

From a design and ergonomics standpoint, the Sierra International MP39090 Ignition Switch 3 Position Magneto is built with practicality in mind. The marine grade glass-filled Polyester housing feels sturdy and substantial, contributing to its overall durability. The anodized steel back up nut and the hex plastic face nut with snap-on rubber cap provide secure mounting and a degree of weather resistance. While not an intricately designed piece, its form follows function perfectly, offering a no-nonsense interface that is easy to operate even with gloves on or in choppy conditions.

In terms of durability and maintenance, this switch is built to last in its intended environment. The materials used, particularly the marine grade glass-filled Polyester, are inherently resistant to UV, saltwater, and general wear and tear. I anticipate this unit will provide years of service with proper installation. There are no complex moving parts that require regular lubrication or adjustment, making it a low-maintenance component. The only potential point of concern would be the rubber cap on the face nut, which, like any rubber component, could degrade over extended UV exposure, but it is easily replaceable if needed.

The Sierra International MP39090 Ignition Switch 3 Position Magneto comes as a single unit; there are no included accessories or direct customization options for the switch itself. However, its 6 screw tab terminal system means it readily interfaces with standard marine-grade wiring and connectors. Compatibility is not an issue; it’s designed to be a direct replacement or upgrade for existing ignition systems that use similar specifications.

Pros and Cons of Sierra International MP39090 Ignition Switch 3 Position Magneto

Who Should Buy Sierra International MP39090 Ignition Switch 3 Position Magneto?

This Sierra International MP39090 Ignition Switch 3 Position Magneto is an excellent choice for boat owners, mechanics working on marine applications, and those maintaining older equipment that requires a reliable, weather-resistant ignition switch. It’s particularly well-suited for anyone looking to replace a failed or corroded switch on an outboard motor or similar marine craft where durability and resistance to the elements are paramount. Individuals who are comfortable with basic electrical wiring and want a dependable component without frills will find this switch to be a perfect fit. However, those seeking a plug-and-play solution with a pre-attached wiring harness might need to procure separate connectors. For users who can handle simple wiring, consider pairing it with marine-grade butt connectors and heat shrink tubing to ensure a watertight and vibration-resistant connection.

Conclusion on Sierra International MP39090 Ignition Switch 3 Position Magneto

The Sierra International MP39090 Ignition Switch 3 Position Magneto stands out as a highly capable and durable component for marine and workshop applications. Its robust construction, coupled with effective corrosion resistance and well-defined electrical ratings, makes it a reliable workhorse. The simple, functional design ensures ease of use, and the push to choke feature adds a valuable layer of convenience for engine starting. Priced at $61.99, it represents a solid investment in reliability, especially when considering the potential costs associated with ignition system failures in harsh environments. I would absolutely recommend this ignition switch to anyone in need of a dependable replacement or upgrade for their marine or workshop equipment. It’s a no-nonsense, built-to-last part that delivers exactly what it promises.