Mercury – 811635K2 Distributor Cap and Rotor Kit | GM 3.0L 4-Cylinder Engines | Delco EST Ignition | 811635K2

Overview

Anyone who’s spent time around boats knows how good it feels when your engine fires up right away — that quick spark, the smooth idle, the steady rhythm that tells you everything’s working like it should. The Mercury 811635K2 Distributor Cap and Rotor Kit helps keep that moment dependable every time you turn the key.

Built for GM 3.0L four-cylinder MerCruiser sterndrive engines running Delco EST ignition systems, this kit replaces both the cap and rotor with factory-quality parts made to handle real marine use. Heat, vibration, and moisture don’t stand a chance — this setup is designed to last and keep your spark clean.

Key Features

• Purpose: Replaces worn ignition components to keep spark timing crisp and consistent.
• Fitment: Designed for GM-based 3.0L 4-cylinder engines with Delco EST ignition, including MerCruiser 3.0L sterndrive models.
• Build Quality: The cap is molded from a durable PBT/PET blend that won’t warp, crack, or distort under engine heat.
• Electrical Contacts: Solid brass terminals stand up to corrosion and keep the electrical flow clean.
• Durability: Balanced strength-to-weight ratio gives it long life and resistance to vibration and thermal stress.

Engine & Boat Compatibility

• MerCruiser 3.0L 4-cylinder sterndrive engines
• Delco EST ignition systems
• Used on smaller cruisers, bowriders, and fishing boats

Performance & Practical Benefits

A good ignition system doesn’t just start the engine — it sets the tone for how your day goes on the water. The 811635K2 kit restores strong, even spark delivery, helping the engine start faster, idle smoother, and respond better when you throttle up.

You’ll feel the difference right away. The brass contacts don’t pit or corrode like cheaper versions, so the current stays steady. The housing material stays firm even after long hours of heat, preventing small misfires that can steal performance or fuel economy. And because it’s OEM, everything lines up perfectly — no trimming, no guessing, just a clean install and a confident first start.

Why Buy OEM

With ignition parts, it’s not just about getting a spark — it’s about getting the right one. Mercury’s OEM components are built specifically for marine use, where heat, vibration, and moisture can ruin lower-quality parts. Every cap and rotor is tested under those conditions before it earns the Mercury name.

Aftermarket versions might save a few dollars, but they rarely match the tight tolerances or brass contact quality that OEM offers. When you go with genuine Mercury, you’re choosing something that’s already proven — something built to keep you off the dock and out on the water.

FAQ

Q1: What engines does the Mercury 811635K2 fit?
A: It fits GM 3.0L 4-cylinder engines with Delco EST ignition, including MerCruiser 3.0L sterndrive models.

Q2: Does this include both the cap and rotor?
A: Yes. The kit includes both — ready to install straight out of the box.

Q3: Can I use it in saltwater?
A: Absolutely. The corrosion-resistant brass and durable plastic housing handle both salt and freshwater conditions.

Q4: Is it easy to install?
A: Very. It’s a direct replacement for the factory part — no modification or adjustment needed.

Q5: When should I replace it?
A: Check it every season or around every 100 hours of run time, especially if you notice misfires or hard starts.