- Water Crafts
currently: 96 XP, 2018 GP1800
Past skis:4 spx,gsx,rxdi,rxt215,rxt255is,xp,gp1200r,SSXI,waveventure
My mechanic who rebuilt my entire engine said use a tank or two of castor oil before switching to synthetic? This is a premix ski. What is the benefit? Will it hurt it if I just use synthetic right from the start?