How to: Removing salt and scale from cooling system passages with vinegar

[Mr. Demeanor]

The test was to see the effectiveness of using vinegar to remove salt and scale deposits from a marine engine.
The test subject is a salt water used 1994 Yamaha 130 V4 with unknown history of maintenance until about 18 months ago. At that time I purchased the engine and have used it about 80% in salt and flushed thoroughly after every use. I recently ran the boat for about 50 miles in fresh water and then a nice salt water run about a week ago.

I filled a large heavy duty garbage can about 2/3 full with water and added 4 gallons of vinegar. The boat has a nosecone and uses a transom mounted water pickup so I disconnected the house, primed the pump, and dropped it into the water then lowered the lower unit as far as possible.

Yes, that is a little grass stuck in the t-stats. Last time out I ran through a lot of floating grass in Charlotte Harbor that gets pickup up by my transom mount pickup.

These are pics of the test subject, thermostats, and housings prior to the test.