My little 1993 6hp Johnson got hot last weekend when i tried to take the Mrs
on an afternnon sail.
Luckily noticed the lack of "pee" from the little outlet that let's one know
the cooling system is doing it's thing before it actually overheated and
shut it down.
Anchored off to the side of the canal leading out to the Banana River and
immediately a young couple offered a tow.
Nice people, boaters. Not all but more than not.
Ordered a new impeller (knew I was pushing the age on the old one) and
replacement parts for the thermostat. When I disassembled the thermostat, it
was clogged with salt, cleaned it up and replaced all parts. On inspection,
the parts didn't need replaced so I have spares. The impeller was old and
stiff but hadn't failed. Reassembled everything.
Fired it up in a bucket and after a few minutes the pee stream stopped
again. Pulled the lower unit again and rigged a small bilge pump (powered
with a jump start power pack) to flush the cooling system through the water
tube that normally goes to the water pump. Flushed the system with vinager
for about 3 hours. Cleaned the thermostat again and this time it was fouled
with sand, which I guess had been trapped from an old grounding (I've had
the motor for 3 years and always on the sailboat whose rudder is about 2
foot deeper in the water than the motor so this must happened in the distant
past on another boat) so I guess the vinager flush dissolved the salt that
had the sand trapped in the system.
Flushed it all a couple more hours and reassembled. Fired it up and it pees
freely now and is cooling well.
So, my new plan is to flush EVERY DAMN TIME I use the motor in salt water
like I know I'm supposed to and do a periodic vinagar rinse.