Sierra 18-5268 Tune Up Kit Gm

Revitalize Your GM Marine Engine with Reliable Tune-Up Essentials

Keeping your GM-based marine engine running smoothly means staying ahead of ignition wear and tear. Harsh saltwater environments accelerate component degradation, leading to misfires, rough idling, and reduced power output. This tune-up kit equips you with high-quality replacements to restore peak performance, ensuring dependable starts and efficient combustion every time you hit the water.

Engineered for durability in demanding boating conditions, these parts resist corrosion and handle high-vibration scenarios better than stock alternatives. Boaters trust them for everything from weekend cruises to extended fishing trips, where reliability isn't optional.

Complete Kit Contents for Thorough Maintenance

• Contact Set: Precision-aligned points deliver consistent spark timing, minimizing dwell variation and extending breaker arm life.
• Condenser: Suppresses arcing for cleaner operation, preventing pitting on contacts and maintaining strong spark energy.
• Distributor Cap: Molded with deep segments to prevent cross-firing, featuring robust terminals that withstand moisture and fuel vapors.
• Rotor: Spring-loaded brass tip ensures solid connection, reducing carbon tracking and improving high-RPM performance.

Every component arrives pre-inspected and matched for seamless integration, saving you time during service intervals.

Perfect Fit for GM Marine Powerplants

Designed specifically for GM V6 and V8 blocks commonly found in sterndrive and inboard setups, this kit matches OEM specifications without the premium markup. It supports a range of applications from 1970s classics to mid-90s models, including popular configurations with Delco distributors. Verify your engine's firing order and dwell angle—typically 28-32 degrees for most V8s—to confirm compatibility during routine checks.

Pro tip: Pair with fresh spark plugs gapped to 0.035 inches for optimal results, transforming hesitant throttles into responsive power delivery.

Why Regular Tune-Ups Matter on the Water

Freshwater corrosion is sneaky, but saltwater is ruthless—it etches terminals, swells phenolic materials, and invites electrical gremlins. Neglected ignition systems cause incomplete burns, spiking fuel use by up to 20% and fouling plugs prematurely. A fresh tune-up sharpens throttle response, quiets pinging under load, and extends overall engine longevity.

Schedule this service every 100 hours or annually, especially if you're trailering through coastal areas. It's a small investment that prevents towboat calls and keeps your adventures uninterrupted.

Step-by-Step Installation Guide for DIY Boaters

1. Prep Work: Disconnect the battery, remove the distributor cap, and note rotor position for timing reference. Clean the base with electrical contact cleaner.
2. Replace Points and Condenser: Gap the contact set to 0.016-0.019 inches using a feeler gauge. Secure the condenser wire away from moving parts.
3. Install New Cap and Rotor: Lubricate the rotor spring lightly with dielectric grease. Ensure terminals seat fully to avoid arcing.
4. Reassemble and Test: Reinstall the cap, set initial timing to 8-10 degrees BTDC at idle, and road-test (or water-test) for smooth operation.
5. Final Checks: Inspect for play in the advance mechanism and recheck dwell after 10 hours of runtime.

Tools needed: Timing light, dwell meter, socket set, and torque wrench. Total time: Under an hour for experienced wrenches.

Long-Term Performance Tips

Shield your investment with marine-grade dielectric grease on all terminals—it repels moisture without migrating. During winterization, spray the distributor exterior with corrosion inhibitor. Monitor vacuum advance hoses for cracks, as they directly impact timing accuracy. For high-hour engines, consider upgrading to Pertronix electronic conversions later, but stick with points kits for authentic reliability now.