obstructed cooling system

[mikebart]

I have a 1997 inshore 90 hp outboard. The cooling system is obstructed, but not sure how to clear it. the hose from the engine block to the hose nipple is clear (visually verified). hooked hose up to the flushing connection at base of cowling and water flows with the exception of the hose mentioned above, the water just barely trickles out. Any suggestions are greatly appreciated.

mike

[jb123]

i use a heavier monoflament or wire leader, which is usually on my boat to clear the clog there, but ensure your impeller / pump is in good working order also.

[Ken]

mike,
Take the hose loose from the nipple and hang it over the lower cowling. Tape it so that it points down. Hook up the motor flusher and run to see if water flows freely out of the hose. If it does, then there is a restriction in the nipple.
Is your motor overheating? Any alarms? If the stream of water coming out the tell/tale hose is weak (assuming there is adequater water pressure and volume at the water pump intake), then you could have a weak water pump and/or restricted water jackets. If it has been at least three years since last water pump repair, it would be a good idea to do it now - need to check for lower unit bolt thread corrosion anyway.
There should be a bolt/plug on top of the head assy that you can easily remove and look down into the water jacket and observe salt/sand deposits. You might want to remove the thermostat cover and inspect it also. I would try flushing the entire cooling system with either "Salt-Away" or "Salt-Terminator".
Good luck,
Ken K