Yamaha f60 cooling issues

[Kotoun75]

hello all,

total weekend mechanic, who is stuck on a cooling issue.

I have a outboard 60 4 stroke that sometimes over heats.

Water pump is good, thermostat is good.

Water flow is inconsistent. did the Neurta Salt flush yesterday but have a few questions:

1. there are two routes that cooling tubes take, one down the ports side and one up the starboard side in to what i believe is the fuel cooler. flow seems to be great on the port side one but the starboard side one is very hard to blow/suck on. is this normal?

2. Where the thermostat goes there is the hole where it is and then a smaller one that i believe the thermostat allows flow into once it gets to a certain temp. should i pour the Neutra salt down that hole as well?

3. over heat alarm goes off when attached to muffs but not as much when engine in a water garbage can. thoughts?

[panasonic]

Sounds like a build up of crap, salt, what ever. Seeing you already have a garbage bucket rigged up why not recirculate the disolving solution. Attach a small hose to the tell tale so it goes back in the bucket and run the engine at idle. If it starts to overheat shut down let cool down and try again...and so on.

There had been many posts on fuel coolers on here and what people had to do too clean them out. I don't know your perticular set up but it sounds like a partial blockage to me. You may have to resort to compressed air to clear out the passages or component disassembly to find it.

I am sure others will chime da once with other options to try as well.

How do you know the water pump is good?

[99yam40]

I had some luck with dropping the lower unit, hooking up a water hose to the pipe heading up to the power head, teed in an air hose to the water hose also, removed the stat housing , turned on water full blast, and then shot blasts of air from time to time into the water running up the motor.
this helped move debris around in the passages and flushed it out of the motor.

if there is solid deposits plugging passages you may need to take apart motor and manual clean it out if chemicals do not get it good enough.

there were a few threads on Rydlyme marine descaler that looked like it did a good job of cleaning cooling systems

[boscoe99]

You say

"I have a outboard 60 4 stroke that sometimes over heats."

Is this when the boat is in the water or is it when the motor is being run on flush muffs or in a barrel?

If it does not over temp when the boat is in the water, you don't have a problem.

Water through those tubes has nothing to do with the motor being cooled. Don't go chasing ghosts.

[Kotoun75]

Thermostat smaller hole

What about this second hole down the side of the thermostat? Should I put some chemicals down there?

[Kotoun75]

You say

"I have a outboard 60 4 stroke that sometimes over heats."

Is this when the boat is in the water or is it when the motor is being run on flush muffs or in a barrel?

If it does not over temp when the boat is in the water, you don't have a problem.

Water through those tubes has nothing to do with the motor being cooled. Don't go chasing ghosts.

Sometimes on the water. That's the issue I'm chasing as it's very inconsistent. Seems to happen just ever once in a while

[boscoe99]

If the water pump is in good condition and the thermostat is in good condition, what did the cavity into which the thermostat resides look like?

If you see evidence of any buildup then I would try the Rydlyme as 99yam suggests. In a barrel as panasonic suggests so that the solution can be circulated over and over again without being wasted. Let the barrel of water get warm in which case it might do a better job of removing scale and deposits. Might even want to remove the thermostat just for the cleaning process to help the stuff recirculate just a bit better.

Presumption being that you have tested the thermosensor and that it is working properly.

[boscoe99]

[TownsendsFJR1300]

You haven't answered, how do you know the water pump is good??

When was it last replaced? Has it sat for a long time unused?

.

[Kotoun75]

water pump was replaced March April is and has been used at least every other week

[TownsendsFJR1300]

Tks.

I gather the WP HOUSING, (not the cup), did not suffer any heat / overheat / warping issues?

[Kotoun75]

That would be above my skill level

[99yam40]

impellers can and do loose vanes some times.
inspection of the pump would not hurt.
kind of sounds like you are not who changed the water pump,
and may not even know if the impeller only was changed or if a complete kit was installed
not to mention is the housing was inspected

[arny]

I would take a look on the anode in exhaust cover.If broken,it can close the cooling passage.You may possible "fishing" it out.