2004 SR Johnson 4 Stroke 9.9-15HP Outboards Service Manual, Page 144Get this manual
POWERHEAD WATER COOLING SYSTEM
WATER COOLING SYSTEM
Operation
The water cooling system consists of the water pump (in the gearcase), water tube (between gearcase and powerhead) and thermostat (in the cylinder)This system cools both the powerhead and the exhaust and is shown in schematic form belowIf overheating occurs, the components of the cooling system must be inspected for blockage, corrosion build-up or damageComponent inspection Refer to page Water pumpImpeller 8-8 Water Tube 8-8 Thermostat 6-34 Cylinder Head 6-10 Cylinder Block 6-23