Piston Kit 3.217 0.30 5006665

Function and technical context

This piston kit for 2-cylinder outboard engines operates at the heart of the combustion system, being the mechanical element responsible for compressing the air-fuel mixture and transforming the energy from the explosion into rotational movement of the crankshaft. The diameter of 3.217" with an oversize of 0.030" (0.030") is specifically designed for cylinder boring, restoring the fit tolerances and compression required in blocks that exhibit cylinder wall wear. The kit includes both the piston and the rings (compression and oil control rings), ensuring optimal sealing between the piston and cylinder. A worn or out-of-tolerance piston causes direct loss of compression, increased fuel consumption, difficulty starting and irregular acceleration, making its replacement critical to restore engine performance. This component is compatible with OMC replacement references 0396581 and 5006665, the latter being the manufacturer's updated reference that supersedes the former.

When should this part be replaced?

The most common symptoms indicating the need to replace the piston and its rings in 2-stroke outboard engines are: presence of blue or whitish smoke in the exhaust (evidence of oil burning due to ring wear), notable loss of compression measured with a compression gauge below the manufacturer's reference values, and elevated fuel consumption with loss of power across the entire operating range. In engines subjected to intensive use, it is recommended to verify piston measurements and the condition of the rings at each seasonal service or after cylinder boring. Taking preventive action at the first signs of wear avoids secondary damage to the cylinder, crankshaft and connecting rod bearings, which entail considerably more expensive repairs.

Compatible Johnson/Evinrude Engines

Equivalent manufacturer references