OceanFlyer Grand Banks 49' Classic Operating Manual page 80

4S1: Sea Strainer Cleaning and Seacocks
The sea strainers on this boat are
secure and reliable. They protect the
engine, generator and refrigeration
cooling systems from water-borne debris
which might block internal equipment
passages. If a sea strainer needs
cleaning (see above regarding
inspection) here is the procedure:
1) Follow the hose from the
strainer to the valve at the hull.
On one side of the valve will be a
handle.
2) Turn the valve lever so it is
perpendicular to the thru-hull or
hose (parallel to the hull).
3) Unscrew the top of the sea
strainer. Then remove the strainer by pulling it out the top of the assembly. Rinse the strainer
thoroughly and, if necessary, remove any debris from the glass housing.
4) Reinsert the strainer, tighten the top cover and turn the valve back on (in line with the
thru-hull itself or its hose).
Failure to re-open the valves will overheat the engine or damage the
pumps!
This entire operation will take 5-10 minutes at most, and will assure you of cool engines.
4S: Sea Strainers & Through-Hulls
Section 4S: Sea Strainers & Thru-Hulls 4.47
The main engine strainers are in the engine room forward centerline.