The Descale Service is performed to remove accumulated marine growth, rust, calcium and mineral deposits from the internal water passages.
The service is done by removing the thermostats and lower unit and pumping a Rydlyme Solution up through the water pickup tube. The solution will flow through the power head and cooling passages breaking down any deposits and allowing better water flow.
The solution should be run through the engine for 2 - 4 hours depending on the build up. When complete, the outboard is flushed with fresh water and reassembled.