MSD Ignition Timing Curve Visualizer

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If you’re running a high-performance jet ski engine, there’s a good chance you’ve come across the MSD 42351 Multi-Channel Ignition Control Module. Though once a popular aftermarket ignition solution for racing and freestyle jet skis, this ignition system has long been discontinued and is no longer supported by MSD. Despite that, many high-output builds still rely on it — and tuning it properly is essential to get the most out of your engine.

That’s why we’ve built this interactive MSD ignition timing curve visualizer, designed specifically for users of the 42351 module.

How It Works

This tool lets you replicate the ignition’s RPM-based timing curve based on the DIP switch settings located under the aluminum plate on the MSD unit. As you toggle the switches and adjust your base timing, the graph updates in real time to show how timing changes across the RPM range — including proper behavior for start retard below 1500 RPM.

Whether you’re dialing in your tune or just trying to understand what the ignition is actually doing, this tool gives you a clear visual of your setup.

MSD 42351 Manual

For full wiring diagrams, DIP switch reference charts, and setup procedures, you can download the original MSD 42351 installation manual here:

📄 Download MSD 42351 Manual (PDF)

This includes details on setting the start retard, holeshot rev limiter, max timing, and rev limit functions.

Why This Matters

As a performance engine builder, we continue to support riders using older ignition systems like the MSD 42351 — even though they’re no longer manufactured. This tool is just one example of how we’re committed to keeping legacy hardware alive and running strong.

If you’re looking to upgrade or replace your ignition setup, or need a custom-tuned high-performance jet ski engine, get in touch — we build some of the most powerful and reliable motors in the industry.