My 502 mag (1998) was running warm so I removed the sea water pump and impeller. Had a few pieces gone and they were not in the housing.

How do I back flush? I thought it was from one of the hoses going into the thermostat housing but there are (4) two on each side. Which hose do I use and how? Just stick a garden hose in the hose?

Thanks,

Padraig

Just disconnect the water hose going into the oil cooler and reach inside the oil cooler. Any Impeller pieces bigger than 1/4 inch will get stuck there.