Mercury Tell Tale / Cooling

diver 1 · 21 January 2016, 20:03

Bit puzzled about the tell tale / water pump on my 1998 3 Cyl Mercury Outboard.. Went out on it on Sunday, all fine, pumping water well as usual, nothing abnormal.

Got home, put it on muffs as I always do to flush through, but no tell tale.

Removed cowl and unplugged tell tale hose from engine block, all fine (no blockage)

Removed gearbox, checked impeller, all fine.

Removed thermostat, cleaned and tested thermostat and housing, all fine, working correctly.

Put hosepipe up through leg of engine into hole water pump goes into, water circulates around engine and exits tell tale as normal, all fine.

When re-assembled still can't get ANY water to come out of the tell tale, just coming out of gear casing area.

Is it because the weather is cold and its taking longer for engine to warm up, thermostat is staying closed to circulate warm water around engine, has something internal frozen and cracked, is the wear on the water pump hosing and wear plate too excessive..? Bit stuck without taking it on the water for a proper test.

Any thoughts / suggestions would be appreciated!

Cheers

A1an · 21 January 2016, 20:10

Did you just use the muffs?

I know my honda 15hp and Yam 20hp struggle to pump water from tell tale whilst on the flush muffs. Stick them in a tank and they pump water with ease.

Try a tank before digging any deeper.

diver 1 · 21 January 2016, 20:23

Thanks Alan, I've read that tonight whilst reading up on it. However I've always flushed this engine on muffs and its always been pretty instant to pump water. Perhaps you're right, something has changed, a great excuse to go for a blast on it after work tomorrow :-) (or a slow splutter using the donkey if the cooling still doesnt work)

jeffstevens763@g · 22 January 2016, 08:23

my muffs dont work low water pressure, i had a flake of salt in my tell tail dont know about the merc but my suzuki had a end piece that comes out to clear it then back blew mine with compressed air you could do it with water too.
cheers

diver 1 · 22 January 2016, 17:59

Stripped it and re-assembled 3 times, testing after each attempt. Now working perfectly again, no idea what problem was. Possibly me turning off engine too quickly and not allowing it a few seconds to fill the engine water ports with water and open thermostat. Anyway thanks, fine now. Looking forward to taking my mrs and 9 month out tomorrow for a slow plod up the harbour. Hoping to test the new Raymarine and new bench seat I've built

diver 1 · 24 January 2016, 20:10

Engine fine again now both on and off muffs. Think it might have hoovered up some fine sand or weed in Christchurch the other week and my messing around eventually cleared out the blockage.

Raymarine Dragonly seems to work well, better than Lowrance unit I reckon