Saltwater flushing - DT65

[kyle_a]

I've got a 1997 DT65. The cooling systems appears to be working, as I've not had any heat related issues. The "telltale" water stream is intermittent on this outboard. I am going to replace the impeller. I started an inspection by removing the thermostat housing and testing the thermostat. I see a moderate amount of salt buildup in the cooling system. Is there something better that water to flush the motor with? Is there anything I can spray into the passages while i have them open to help disolve the salt that is already there? I've tried the search function, but it fails with "security token not attached" Thanks.

[wjm7947]

You should be flushing with ear muffs and a good flow of water. Your motor should be run for 10 minutes. That will let heat build up and the thermostat to open wide and flush the head and entire motor.

[kyle_a]

So riddle me this: Is the telltale stream supposed to run 100% of the time, or does it only flow when the thermostat is open? Thanks.

[pinecpt]

Should run 100% of the time.

[Harper]

Yep, tell tale is only an indication a working water pump, not of a properly operating cooling system. In other words, even if the thermostat failed in a closed postiton, causing the engine to overheat, the tell tale would have still been pumping away as if all was A-okay. You'll notice while flushing the motor on the muffs, that the water coming out of the tell tale is cold, while the water coming through the prop is warm, having gone by the opened thermostat and through the engine's cooling passages.