Lesser-known cause of two-stroke wear: ring sticking often begins as varnish from oxidised fuel and oil residues on cool cylinder walls, not from soot. In seasonal use typical in the Nordics, equipment sits with aged petrol; ethanol blends draw moisture and can phase-separate, leaving pockets that wash oil off and promote scuffing at the first restart. Detergent solvency in the oil helps keep deposits soft and mobile so rings can seal instead of scraping. Using a suitable two-stroke lubricant, such as 2T Eco Green, supports cleaner ports and steadier compression.