ARCO Marine Mercury/Mariner Outboard Starter - 8 Tooth

The ARCO Marine Mercury/Mariner Outboard Starter - 8 Tooth is a dynamically tested OEM replacement starter engineered for Mercury and Mariner outboard motors in the 80–125 HP range. This 8-tooth drive gear starter (Part Number 5392) delivers reliable cold-start performance in marine environments where electrical demand and corrosion present constant challenges. Built to factory specifications, it restores original starting torque and engagement characteristics without modification to existing wiring or solenoid circuits.

Weighing 7.4 lbs and dimensioned at 5 × 4 × 12 inches, this starter integrates directly into OEM mounting points on Inline 4-cylinder and 80 HP Jet configurations. The 8-tooth pinion gear matches factory ring gear ratios for precise engagement and full electrical load transfer. ARCO recommends using a fully charged battery during operation—weak battery voltage can damage both the starter and solenoid by causing excessive current draw and heat stress. Salt spray and moisture corrosion at electrical connections significantly reduce circuit amperage; thorough cleaning of all battery terminals and engine ground points before installation ensures the full starting circuit current reaches the starter motor without resistance losses.

This starter serves commercial fishing operations, recreational boaters, and marine service technicians who require predictable starting reliability in salt-air environments. Whether replacing a failed starter on a 100 HP Mariner inline or upgrading a 125 HP Mercury powerhead, this ARCO unit provides OEM-level performance and fit. Its tested, ready-to-install condition eliminates guesswork and core returns typical of refurbished units.

The marine outboard starter market demands both electrical reliability and corrosion resistance; this ARCO starter addresses both through robust construction and proper installation practices. Confirm your specific engine displacement and year against documentation before ordering to ensure 8-tooth compatibility—9-tooth variants exist for different HP ratings.