Thermostat – Fits Johnson Evinrude 6-250 HP V4/V6 (Replaces Johnson/Evinrude 5005440, 434841) 25-400HP Tighten both plugs to be

Tighten both plugs to be snug

Brand Part Number Yamaha 63D-W0078-01-00 Yamaha 63D-W0078-03-00 Sierra 18-3415 Sierra 18-3434

It should be snug but not overly tight

start the engine at idle and confirm a steady stream of water from the tell-tale port

check or replace the filter every 100–200 service hours

Thermostat – Fits Johnson Evinrude 6-250 HP V4/V6 (Replaces Johnson/Evinrude 5005440, 434841) 25-400HP Tighten both plugs to beProduct Details This replacement Thermostat Fits Johnson Evinrude 6 250 HP V4 V6 Outboard Motors is designed for a broad range of 2 stroke and 4 stroke engines. It is engineered for Johnson Evinrude 6250 HP 2 Stroke V4 V6 models (19732006) and 9. 915 HP 4 Stroke models (19942001). It also serves as a compatible replacement for select Mercury Mariner and Yamaha outboards. This part directly interchanges with Johnson Evinrude 5005440 434841, Mercury