Thought I would pass this info along. Last year I bought a 91 600 lc4 from a buddy that lost compression . Finally tore it apart about a month ago to round up parts and get it running. Piston and bore where ok but rings were rusted and stuck, pulled old rings off and cleaned ring grooves out of all rust and gunk figuring a new set of rings and good to go. Couldn't locate a set of rings for the stock 95mm piston from several KTM dealers or aftermarket manufactures. Did some research and found that Yamaha XT/Grizzly 600's have the same bore as the 600 KTM's, picked up a set off e-bay for $28 with shipping. Put everything back together today and now runs like a champ!