Building a 44ft Quad-Tune Pontoon: Mounting Twin 250HP Engines

In this episode of B is for Build, the team takes on the Herculean task of mounting twin 250 horsepower Mercury Verado engines on a massive 44-foot quad-tune pontoon yacht. Yes, you heard that right - a pontoon boat with not one, but two powerful engines, totaling a whopping 500 horsepower. This is not your average leisurely cruise on the lake; this is a bold move that pushes the boundaries of traditional pontoon boat configurations. Will it work? Well, that's the million-dollar question, and the team is ready to find out.

The process begins with meticulous welding of the boat, followed by the construction of a hot tub enclosure and custom decking. Water testing is crucial to ensure the boat's integrity, with special attention given to making sure every pontoon section is airtight. Structural supports are added to facilitate moving the boat around the shop and eventually onto a shipping truck. The engines, purchased used, present a new challenge for the team, as they dive into the world of boat engine mechanics with little prior experience.

With a mix of CAD designs and good old-fashioned trial and error, the team sets out to mount the engines in a unique outboard-inboard configuration. The redesign of the engine mounts using quarter-inch aluminum and additional supports showcases their commitment to getting it right. As the first engine is successfully mounted, the team faces unexpected hurdles and adjusts their approach on the fly. Stay tuned as B is for Build navigates uncharted waters in their quest to bring this unconventional pontoon yacht to life.

Watch Building My Dream Yacht From Scratch Pt 5 - Innovative Inboard`ish-Outboard Engine Mounting! on Youtube

Viewer Reactions for Building My Dream Yacht From Scratch Pt 5 - Innovative Inboard`ish-Outboard Engine Mounting!

"Don't make bathtubs" - include drainage holes in engine mounts
Use Tef Gel or Anti Seize on bolts to prevent galvanic corrosion
Check Fuel Supply Units before launching
Consider adding a bow thruster for better maneuverability
Install a bilge pump inside the hot tub compartment
Add a skid plate for buoyancy, stability, and storage
Ensure hot tub has its own bilge
Consider a Transom Plate for even distribution of engine force
Weld aluminum band over butt joints on pontoons
Use aircraft-grade bolts for engines