Suzuki Outboards – Fighting Corrosion
Monday, February 16th, 2015
Comprehensive Construction
This system starts with the construction of Suzuki Outboard Motors. Suzuki outboard engines are cast from extra-strong, high grade aluminum alloys. Next comes a multi-step surface treatment, beginning with a thorough cleaning of the aluminum alloy castings in a special chemical bath that removes any impurities or contaminants that might interfere with the adhesion of the surface coatings.
Once cleaned, the engine castings are submerged in an electrified bath of CrO2 (chromium oxide), or Alodine. This process alters the chemical composition of the surface, creating an invisible barrier that becomes an integral part of the casting to seal out corrosion.
Suzuki Outboards then receive an extremely hard and resilient baked-on epoxy resin primer engineered especially for marine applications. The epoxy primer completely covers all surfaces. Once fully primered, the engine is given a final coat of a specialized Melamine resin marine grade paint. The Melamine paint cures to a tough yet lustrous finish to completely seal the engine castings from the saltwater environment. The result is an engine that is effectively triple-sealed against saltwater.
The Little Things Mean a Lot
This comprehensive surface treatment is only part of Suzuki’s anti-corrosion system. Along with these procedures, several special sacrificial zinc anodes are strategically placed both externally and within the cooling water passages. These replaceable zinc anodes take on the brunt of saltwater’s corrosive action, sacrificing themselves over time to preserve the overall integrity of the engine.
To help the zinc anodes work most effectively, Suzuki Outboard Motors incorporate several special external and internal bonding wires on all models (except the 5 and 6 hp models), uniting all major engine parts. This seemingly simple but important step ensures that any corrosive action is directed away from metal engine components and toward the anodes.
Finishing Touches
Another key element in Suzuki’s anti-corrosion system is specialized marine-grade stainless steel, used for propellers, propeller shafts, driveshafts, shift rods and more. Stainless steel is also used for bolts, nuts and washers exposed to saltwater.
To further prevent galvanic corrosion, key bolts, nuts and washers are also coated with chrome plating or Dacromate, a specialized corrosion-fighting marine primer, to create a barrier between dissimilar metals. Cylinder head bolts and exhaust cover bolts are chrome-plated for added durability. Finally, exposed portions of primered stainless steel and tempered steel bolts, nuts and washers are sealed with a final coat of Melamine resin paint.
As part of the Suzuki advanced anti-corrosion system, the water pump housings on all prop-driven Suzuki outboards are also durable, corrosion-resistant stainless steel. This feature ensures that corrosion does not form within the water pump – and thus will not interfere with the all-important cooling function of the engine.
In addition to all of these corrosion fighting features, the one-piece engine hood and baffled air induction systems on Suzuki outboard engines effectively seal the powerhead from saltwater. This advanced anti-corrosion system has earned Suzuki engines an enviable reputation for reliability, durability and corrosion resistance from coast to coast – especially where corrosion is worst.
