How can I determine whether my piston is reusable so as to replace just the piston rings?

The most common problem of a piston that needs replacement is in case there are scratches on its body.

What other parts I may need to replace when replacing the piston rings?

To replace the piston rings you need to disassemble the engine, so you also need to replace the cylinder gasket.

$14.07

In stock

Piston Ring Set for OLEO-MAC 251S, 254F, 350AF, 950FS, 950S, 951, DYNAMAC DY51 Chainsaws [#5400015] and related spare parts.

This listing is about a brand new after-market top-quality Piston Ring SetTips for safely installing piston rings made by the well-known OEM firm CABER which fits the following OLEO-MACSpare parts for OLEO-MAC machines models, and DYNAMAC DY51, and replaces OEM Part #5400015:

Specifications
Country of Origin	Italy
Product Code	1002440
Compatible Brand	OLEO-MAC
Compatible Models	OLEO-MAC 254F, 350AF Super, 251S, 950FS, 950S, 254, 951, DYNAMAC DY51
OEM Part #	5400015, 005400015