Back flushing cooling system

[Dade22]

Can someone explain how to back flush cooling system in 2003 22v for debris?

[boatwakes]

Remove the hose that comes out of the raw water pump and goes to the engine block. Remove the hose where it connects to the thermostat housing from the raw water pump. Use a garden hose to feed water into the hose you removed from the thermostat and watch what comes out the other end you removed from the raw water pump. If its a Mercruiser, your raw water pump is on the actual front of the engine (back of the boat) on the bottom of the port side. Indmar or Marine Power use a raw water pump driven by the crankshaft.