my 26' tolly has a freshwater cooling system. i put new water lines on
last year so everything is in great shape.

took it out last weekend in the fairway to practice docking. engine
kept stalling at slow speed (600 rpm). got it back into the slip and
found the bilge pump was running. opened the bilge and found the
cooling water line from the throughull to the cooling water pump had
completely collapsed even though it was wire reinforced. the end of
the line had ripped away from the throughhull and water was streaming
in.

i shut the seacock and let the boat pump out put a new water line on,
started the engine and it ran like a charm with no overheating.

looking at the collapsed line...i remembered that the previous week
the marina had filled with seaweed. some of this probably got stuck on
the strainer and blocked the inlet.

before i put the new water line on, i backflushed the strainer with
water and got good flow. but will keep an eye out for seaweed in the
future.