Engine Installation

Overview
Of the personal projects I've done over the years, this project stands out as one of the most challenging. In short, it involved replacing the engine on a 1983 Ericson-35 sailboat. The process includes steps like removing the old engine, selecting a compatible replacement, and rummaging through enough documentation to drive even the most sane person crazy. Below are photos documenting key parts of the process.

Figure 1: Original Engine (Non-functional)

Figure 2: Replacement Engine | M-25XPB

Figure 3: Engine Bay and Footprint Template

Figure 4: Crane Fitting and Placement

Figure 5: Completed Installation — Plumbed, Wired, and Mechanically Coupled

Custom Mounts and Alignment
One major challenge was fabricating a new mounting surface. The replacement engine’s mounting feet were in different locations, so half-inch aluminum plates were cut, positioned, and secured on top of the existing fiberglass bed. Using a template ensured precise alignment along all three axes. Accuracy here was critical. The engine’s drivetrain had to perfectly align with the propeller coupling plate to prevent excessive transmission wear and cockpit vibration.

Wiring, Plumbing, and Fitment
Additional hurdles included adapting wiring harnesses, plumbing, and throttle cables to fit the new engine. Anti-siphon mechanisms were installed to protect the cylinders from seawater in rough conditions, a raw water strainer was installed, and new exhaust hoses and fuel lines were run.

Unexpected Setback
Upon engine startup, excessive cockpit vibration raised alarms. After troubleshooting, the cause was traced to a minutely bent propeller shaft. This runout was on the order of thousandths of an inch but we new it needed to be fixed. On the bright side, this was unrelated to the installation work. Nonetheless, fixing it required pulling the brand-new engine back out, replacing the shaft, and reinstalling the engine a second time. The running joke is that we can now install it blindfolded.

Takeaways
Despite the challenges, this project was an incredible learning experience and deeply rewarding. Hearing the engine run smoothly on the water for the first time was a proud milestone.

Preparations
Before engine removal, each hose, wire, and component was carefully documented and understood to ensure accurate mapping onto the replacement engine, particularly since the layouts were not identical. Although the engine bay may appear chaotic at first glance, every element serves a critical function within the system.