Blew piston on mag side cylinder looks excellent no scratches at all, bottom of piston skirt says SBT so Iím assuming the engine has been opened up before. The pistons have 100 scribed on them so my question is can I use same sleeves and can I go with larger pistons? And pistons both dark and oily so doesnít that mean they were running rich? Can you blow an engine running rich? Thanks for your help! Also is there any warranty on pistons or just motor rebuilds? I donít know anything about the ski!